Proceedings o f a Panel Vienna, 18-22 March 1974 p organized by the — Joint FA O /IA E A Division of Atom ic Energy in Food and Agriculture Requirements for the Irradiation of Food on a Commercial Scale

V i w j INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1 975

REQUIREMENTS FOR THE IRRADIATION OF FOOD ON A COMMERCIAL SCALE

PANEL PROCEEDINGS SERIES

REQUIREMENTS FOR THE IRRADIATION OF FOOD ON A COMMERCIAL SCALE

PROCEEDINGS OF A PANEL ON THE COMMERCIALIZATION OF IRRADIATED FOOD ITEMS ACCEPTED FOR HUMAN CONSUMPTION ORGANIZED BY THE JOINT FAO/IAEA DIVISION OF ATOMIC ENERGY IN FOOD AND AGRICULTURE AND HELD IN VIENNA, 18-22 MARCH 1974

INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 197 5 REQUIREMENTS FOR THE IRRADIATION OF FOOD ON A COMMERCIAL SCALE IAEA, VIENNA, 197 5 STI/PUB/394 ISBN 92-0-111275-0

Printed by the IAEA in Austria

M a rch 1 9 7 5 FOREWORD

In the task of securing enough food for the world’s increasing population, it is absolutely essential to cut down the present huge losses occurring during the storage and transport of foods. As a method of food preservation, irradiation is a promising addition to such conventional methods as heat treatment, refrigeration, and the application of chemicals (preservatives, fumigants). It is widely accepted that, in parallel with the world-wide introduction of the traditional methods, all promising new techniques, including the use of nuclear energy, should be carefully studied for their practical suitability. However, in spite of thorough research over a long period, only a few pilot-plant-scale sources and only one commercial-scale food irradiator exist at present in the world, although various irradiated foods are now legally permitted for human consumption in a number of countries. The Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA), in keeping with their statutory obligations, are studying this situation, intent on analysing the reasons for the apparent contradiction between the urgent need for, and the lagging introduction of, food irradiation on a practical scale. As a part of their continuing programme on this subject, which has produced a number of books published by the Agency, the Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture held a panel on 18-22 March 1974 in Vienna attended by 16 experts and seven representatives of international and inter-governmental organizations (FAO, IAEA, WHO and EC). The papers presented, together with a summary of the discussions, conclusions and recommendations, are included in the present book, which gives an up-to-date picture of the present situation in those countries foremost in developing and applying this technique and indicates the direction of future work.

CONTENTS

PAPERS PRESENTED C on sid eration s fo r an analysis o f the value o f p o ta to irradiation in Spain ...... 3 F. de la Cruz, N. Or tin Suñé United States potentials and problems for insect disinfestation o f wheat and sprout in h ib itio n o f p o ta to e s b y irradiation ...... 13 J. Deitch Preparations for marketing irradiated potatoes and onions in the Federal Republic o f G erm an y ...... 31 J.F. Diehl Present status and prospects for the commercialization in Hungary o f irradiated food item s fo r hum an c o n s u m p t i o n ...... 37 J. Farkas Petitions and clearances for irradiated food items: Implementation.of legislative requ irem en ts in m arketin g t e s t s ...... 61 E. Eisenberg, E. Foa, M. Lapidot, R. Padova, K. Rosenberg, I. Ross Irradiation treatment for sprout inhibition in potatoes: Prospects for application in B elgium ...... 69 W. Schietecatte, L. Nys P rospects o f o n io n irradiation in I n d i a ...... 89 P. Sudarsan Background to the establishment o f the first food irradiation plant in Japan ...... 113 K. Umeda Commercialization of irradiated potatoes, mushrooms, onions and spices in the N etherlands ...... 133 D. de Zeeuw P reparation fo r the in tro d u c tio n o f fo o d irradiation in Brazil ...... 141 L. Zonenschain

STATEMENTS AND STATUS REPORTS Statement of the WHO representative on the wholesomeness of irradiated foods ...... 157 M. Sentid P ublic a ccep ta b ility o f fo o d irradiation ...... 159 G. Propstl Notes on the food irradiation programme in Italy with particular reference to potatoes . . 167 D. Baraldi Preparations for commercialization of irradiated food items in the Czechoslovak Socialist R e p u b lic '...... 175 P. Horacek Status o f the fo o d irradiation program m e in Israel ...... 179 M. Lapidot Possibilities and problems of introducing radiation preservation of foodstuffs in Uruguay . 181 F.G. Merino Status o f p o ta to irradiation in F rance ...... 1'83 F. Sandret P ota to and o n io n irradiation in the N eth erlands ...... 185 H. Sparenberg T h e e c o n o m ic feasibility o f o n io n , p o ta to and w h eat irradiation in India ...... 197 P. Sudarsan C on su m er attitu des tow ards fo o d irradiation in the N e th e r la n d s ...... 203 J. G. van Kooij S U M M A R Y A N D R E C O M M E N D A T IO N S ...... 207 L IST O F P A R T I C I P A N T S ...... 2 17 PAPERS PRESENTED

CONSIDERATIONS FOR AN ANALYSIS OF THE VALUE OF POTATO IRRADIATION IN SPAIN

F. DE LA CRUZ, N . ORTIN SUNE Junta de Energía Nuclear, Madrid, Spain

Abstract

CONSIDERATIONS FOR AN ANALYSIS OF THE VALUE OF POTATO IRRADIATION IN SPAIN.

The irradiation of potatoes to inhibit sprouting could be of value for the preservation of approximately

50“/o of the late potato production. The cost of irradiation should be competitive with that of treatment by chem ical sprout inhibitors. Considering the present organization and location of the storage units, the

use of a fixed irradiator seems inadvisable; it wculd be better to use m obile irradiators for continuous operation, if possible with conveyor belts. Irradiation of potatoes is of particular interest in the case of

potato crisp manufacturers, who have to store the potatoes for a longer period than required in the case of

food potatoes. The irradiation process could be Df com mercial value for the preservation of select

varieties, thus furthering the marketing of special product presented in high-quality form.

1. INTRODUCTION

The production and marketing of potatoes in Spain has been studied, taking into account the various harvesting periods and present methods of storage and distribution. To assess the possible value of a national system of storage-distribution units and special factories for the treat­ ment of potatoes by irradiation the authors have carried out a survey based on a series of personal interviews.

2. POTATO PRODUCTION IN SPAIN

Potatoes are produced throughout Spain; the wide range of varieties produced has been thoroughly studied by centres for research and .crop improvement.

2.1. Varieties

The cultivated potato varieties are grouped in the following manner1 in accordance with the laws now in force (Order of 6/9/72):

High-quality potatoes: Arran Banner; Avenir; Bintje; Claudia; Claustar; Desiree; Duquesa; Estrella de León; Jaerla; Kennebec; K err's Pink; King Edward; Perilland Doll; Red Craig1 s Royal; Red Pontiac; Royal Kidney; Turia; Urgenta; and Up to date.

1 Taken from Harvesting and Marketing Í chedules. Fruit and Horticultural Products, Ministry of

Agriculture (1973).

3 TABLE I. PRODUCTION OF POTATOES IN SPAIN (Campaign 1970-71)

V ery e a rly Early M i d -s e a s o n L ate T o t a l R eg io n ° lo t °Io t °Jo t % t °1°

1 Castilla la Nueva - - 2 1 8 2 9 3 . 1 1 3 9 6 0 5 5 . 9 1 9 0 8 7 0 8 . 9 3 5 2 3 0 4 6 . 6

2 Castilla la Vieja - - 6 9 3 0 . 1 1 1 2 0 8 8 4 . 7 4 8 4 4 0 5 2 2 . 6 5 9 7 1 86 1 1 . 3

3 L e o n e sa - - 6 7 7 0 1. о 2 3 0 1 5 0 9 . 7 3 9 3 2 3 0 1 8 . 3 6 3 0 1 50 1 1 . 9 E N SU ORTIN and CRUZ LADE

4 Extremadura - . - 2 6 8 2 0 3 . 8 17 6 4 0 0 . 7 2 9 8 0 0 1 . 4 7 4 2 6 0 1 . 4

5 Andalucia Occidental 9 5 0 ' 1 . 1 1 0 3 0 57 1 4 . 6 3 1 91 0 . 1 4 3 2 4 4 2 . 0 1 5 0 3 8 7 2 . 8

6 Andalucia Oriental 2 4 2 2 0 3 0 . 7 5 2 6 4 4 7 . 5 1 0 3 0 77 4 . 3 3 0 1 4 0 1 . 4 2 1 0 0 8 1 4 . 0 '

7 L e v a n te 3 0 0 0 . 4 2 0 2 9 80 2 8 . 8 8 4 8 7 5 3 . 6 8 1 2 2 4 3 . 8 3 6 9 3 7 9 7 . 0

8 Cataluna-Baleares - - 1 1 1 7 4 7 1 5 . 9 1 5 4 9 9 0 6 . 5 8 6 2 3 4 4 . 0 3 5 2 9 71 6 . 7

9 A r a g ó n - - 7 0 7 8 1 . 0 8 1 2 6 4 3 . 4 6 4 3 1 2 3 . 0 1 5 2 6 5 4 2 . 9

10 Rioja-Navarra - - 4 2 0 0 . 1 1 3 0 4 1 6 5 . 5 . 7 9 3 4 0 3 . 7 2 1 0 1 7 6 4 . 0

11 Vascongadas - - 4 3 2 2 0 . 6 6 7 2 9 8 2 . 8 3 6 3 8 7 1 . 7 1 0 8 0 07 2 . 1

12 Asturias-Santander 2 1 0 0 . 3 4 3 2 4 8 6 . 1 1 9 9 8 63 8 . 4 1 0 5 4 0 6 4 . 9 3 4 8 7 2 7 6 . 6

13 G a lic ia 1 5 5 2 . 9 5 7 8 8 0 8 . 2 1 0 3 0 5 8 8 4 3 . 5 5 1 4 3 3 5 2 4 . 0 1 6 0 4 3 5 3 3 0 . 3

14 Canarias 5 1 6 2 3 6 5 . 5 6 4 7 6 0 9 . 2 1 5 0 5 0 0 . 6 8 6 0 0 0 . 4 1 4 0 0 33 2 . 6

TOTAL 7 8 7 9 8 7 0 4 2 4 8 2 3 7 0 0 9 6 2 1 4 7 5 2 7 5 3 0 0 6 6 9 OAOS N IN A P S IN POTATOES

Taken together, the regions shown produce the following yields in the different har­ vests: Very early (ET): 96.2? 0 Early (TE): 76.7# Mid—season (ME):74*0$ Late (TA): 73.9$ 0 о К? Й ' к f i

FIG. 1. The major potato producing regions of Spain. 6 DE LA CRUZ and ORTIN SUÑÉ

Ordinary potatoes: Alava; Alpha; Gineke; Goya; Olalla; Palogan; Sergen; Victor; etc.

The designation "high-quality potatoes" refers, in addition to variety, to dimensions of between 30 and 40 mm.

2.2. Geographical distribution of production

Table I shows the production figures for the different harvests in Spain (campaign 1970-1971), indicating the volume by region and per­ centage of the total. Figure 1 gives data for those regions of Spain with the highest production, indicating also the percentages of the different harvests: very early, early, mid-season and late.

FIG. 2. Tim e-table of potato production and periods of maximum harvest. POTATOES IN SPAIN 7

2.3. Harvesting schedule

The percentage distribution of the different harvests relative to the total production is as follows:

Very early potatoes: 1.5%; Early potatoes: 13.3%; Mid-season potatoes: 44.7%; Late potatoes: 40.5%.

Thus, 85.2% of the total is produced in the mid-season and late harvests, collected after 15 June. Figure 2 is a schematic time-table of potato production showing the periods of maximum harvest and indicating the quantities corresponding to each type of harvest.

2.4. Consumption

Of the total production of potatoes (see Table I) some 13.2% (700 000 t) are used for cattle feeding and some 2.6% (140 000 t) are used in industry; the rest is used for human consumption. The average assumed values for human consumption vary between 100 and 250 g per inhabitant per day, no account being taken of consumption in rural areas.

3. PRESENT METHODS OF PRESERVATION

3.1. General considerations

In Spain the preservation of food potatoes - when necessary - is based generally on the use of chemical sprouting inhibitors, in particular IPC, which is supplied to storage-distribution units under various commercial names. In view of the different harvest periods found in Spain and taking into account the maximum harvest periods, the following points should be s t r e s s e d :

(a) Very early, early or mid-season potatoes are not preserved since these are not subject to sprouting in storage, being marketed and consumed before sprouting takes place; (b) Only about 50% of the yield of the late Spanish harvest needs preserving, the remaining 50% being marketed and distributed before sprouting can take place.

The food potato is seldom refrigerated. This treatment is normally applied to the seed potato.

3.2. Storage

Since the potato is cultivated over the whole of Spain, there are large numbers of stores situated throughout the country. Figure 3 indicates the most representative ones, which are used by the more important distri­ butors in the marketing process and are fitted with special installations for ventilation and aeration; some of them are palletized as well. E A RZ n OTN UNE N SU ORTIN and CRUZ LADE

FIG. 3. Location of the major storage units. POTATOES IN SPAIN 9

3.3. Losses during storage

Where chemical sprouting inhibitors are used, present losses can be estimated at some 3-5% of the stored 50% of the late harvest.

3.4. Cost of treatment

The cost of treatment with IPC is estimated at about Ó.10-0.15 pesetas/kg of potatoes, including the cost of the product and all the operations involved in its application. The cost of refrigeration for seed potatoes is 0.20-0.30 pesetas/kg per month. If the refrigeration temperatures required are not too low, the cost of this treatment for food potatoes is of the order of 0.15 pesetas/kg per month, although, as already mentioned, refrigeration is very rarely employed in potato marketing.

4. ASSESSMENT OF THE VALUE OF A CHAIN OF STORAGE- DISTRIBUTION AND MANUFACTURING UNITS FOR THE PRESERVATION OF POTATOES BY IRRADIATION

To furnish a realistic estimate of the value of introducing irradiation preservation of potatoes in Spain information was gathered from a number of storage-distribution enterprises that can be regarded as representative of Spanish potato marketing. The survey was also extended to manu­ facturing concerns. The results of these inquiries are summarized below; of course, they are based on the assumption that irradiation treatment is technologically feasible and on the fact that Spain has approved human consumption of irradiated potatoes.

4.1. Storage-distribution units

Figure 3 indicates the location of the storage enterprises consulted, while Fig.4 shows the areas from which they obtain their supplies. Some 170 000 tonnes of potatoes are marketed by these enterprises annually. No disadvantage is anticipated as a result of treatment by irradiation. The optimum period for delayed sprouting, taking into account the marketing cycle, is estimated at 4-6 months. In principle, the maximum price that could at present be paid for irradiation treatment would be 0.10 pesetas/kg of potato, assuming six months' storage without sprouting. In some isolated cases it is believed that irradiation treatment, by extending the storage period of late potatoes, would reduce the price of early potatoes. It is not thought that the irradiation of potatoes would affect production since consumers prefer early potatoes, even though late potatoes may still be available on the market. The type of irradiation facility preferred is the continuous, mobile, type, if possible with conveyor belts. Some of those who replied (25%) thought that if storage could be pro­ longed by the use of irradiation, it would be possible to market more potatoes. The remainder did not believe that greater quantities would be marketed since the present distribution requirements are being met. E A RZ n OTN UNE N SU ORTIN and CRUZ LADE

FIG . 4 . Areas supplying the storage-distribution units. POTATOES IN SPAIN 11

4.2. Manufacturing concerns, potato crisp factories

The large-scale industrial production of potato crisps in Spain can be estimated at about 60 000 - 70 000 t annually, not including the output of small concerns, which produce and supply directly to the public. There is a fairly large number of these firms in Spain. These industrial concerns make use of installations that produce potato crisps at a rate of about 2 t/h and are operated for approximately 3800 hours per annum. Normally, very early potatoes are not used because of their high price and unsuitable processing characteristics. The early potato is used to á small extent but an effort is being made to eliminate it from the manufacturing process. The mid-season potato covers about 25% of the needs, the remaining 75% being met by late p o ta to e s . One of the manufacturing concerns stated that it stores some 30 000 t of potatoes a year, with a maximum storage peak of 13 000 t. The most suitable varieties for the process are Turia, Kennebec and Desiree. The losses over a period of eight months are small since the factory stores are fitted with equipment for aeration and humidity and temperature control. When required, IPC is used to inhibit sprouting.

ACKNOWLEDGEMENTS

The authors wish to express their thanks to Mr. Lobo, Head of the Seed Potatoes Department (Select Seed Institute) and to Mr. Gandarias and Mr. Chara of the National Potato Group (National Association of Fruit and Horticultural Products) for information provided. Thanks are also due to the following potato groups: Comercial Agrícola Riojana, Ibérica Almacenista de Patatas, Julian Sanz. Finally, the authors wish to thank Mr. Berja, Deputy Director General (Technical) of Alimentos Ligeros S.A., for information provided.

UNITED STATES POTENTIALS AND PROBLEMS FOR INSECT DISINFESTATION OF WHEAT AND SPROUT INHIBITION OF POTATOES BY IRRADIATION

J. DEITCH US Department o f Com m erce, Domestic and Business Administration, Washington, D.C., United States of America

Abstract

UNITED STATES POTENTIALS AND PROBLEMS FOR INSECT DISINFESTATION OF WHEAT AND SPROUT INHIBITION OF POTATOES BY IRRADIATION.

The paper discusses the production, harvest and storage of wheat and wheat flour and white potatoes in the United States o f Am erica. Also described are the approved petitions for wheat and wheat flour and white potatoes, production tests and studies of irradiated products and results. The paper examines the public attitude, support for and interest in food irradiation in the United States.

WHEAT

Harvest and storage

Prospects in the United States of America for insect disinfestation of wheat by irradiation can best be gauged by examining the wheat and flour operations in the United States and the extent of the insect problem. Wheat is grown in almost every state in the USA. About 60% of the country's wheat crop is produced in the central part of the country, from Texas to the Canadian border. In 197 3 the United States produced 46 million m etric tons of wheat, which is about 15% of world production. Harvesting of wheat starts as early as May in the south-west and pro­ ceeds north through August. Some of the harvest may be stored on the farm for later sales at a better price, or sold to a flour mill. Most wheat, however, is trucked and sold by the farmer to one of the 20 000 local elevators that are located conveniently in the wheat-growing areas. From the local elevator the wheat is transferred by rail, truck, sometimes by barge to mills but primarily to the large centrally located storage centres. Some storage terminal elevators can store as much as 40 to 50 million bushels (1.08 - 1.35 million metric tons) of wheat. The care and handling of wheat at the large terminal elevators is highly mechanized and is much the same throughout the USA. Before wheat is stored it is tested and evaluated for quality, foreign matter and for infestation. Some terminal operators prefer to fumigate wheat during loading into the storage bins, while others treat the wheat only if there are signs of infestation during storage or when the wheat is transferred to carriers for shipment to flour mills or for export. The condition of the wheat is carefully checked by instruments for excess moisture or for tem­ perature changes that may indicate insect infestation. If fumigation or cool­ ing is required, the wheat is treated as a part of the procedure of rotating

13- 14 DEITCH the wheat from one storage bin to another, which helps to keep the wheat in prime condition. Cooling wheat below 10°C (50°F) by forced aeration during the winter is very effective in controlling insect growth. The wheat stays cold for many months, preventing insect propagation. Fumigants most commonly used are the 80 - 20 preparation of carbon tetrachloride and carbon disulphide, methyl bromide, and phosphine gas, which is solid in tablet, pellet or granular formulation of aluminium phosphide. The fumigants not only destroy live adult insects, but if used properly are effective in killing eggs, larvae and pupae of the species that develop inside the wheat kernel. Terminal grain operators and wheat m illers agree that insect infesta­ tion of wheat and of flour in the United States is now minimal and very much controlled due to well-constructed facilities and improvements in grain handling. Vigorous sanitation regulations and guidance promulgated by the United States Department of Agriculture and the Food and Drug Administra­ tion as well as modern milling equipment are important factors in the production of flour today that is virtually insect free.

;

Flour production

Millers test each wheat shipment before it is accepted for unloading in the m ill's storage elevator, and reject wheat that shows signs of insect infestation. Rejected wheat is returned to the seller who may fumigate it or sell it as animal feed. Flour mills do not have large storage capacities and require shipments from storage terminals during the year. Large mills using as much as 2 million bushels (0.054 million metric tons) of wheat a month seldom store wheat longer than 2 to 3 months. Wheat intended for longer storage is fumigated. Smaller millers who may have capacities for 6 months' storage or longer have told me that they fumigate wheat they plan to store longer than two months with phosphine as the wheat is transferred into their storage silos. Millers in the northern locations also depend on cooling wheat to prevent infestation.

Wheat for export

The purchase of large quantities of wheat by the Soviet Union from the United States in 1972 led the Chairman of the Joint Committee on Atomic Energy, Congress of the United States, to inquire about the possible use of radiation in providing insect-free wheat to Russia. In response, members of the US Government Interdepartmental Committee on Radiation Preserva­ tion of Food met in May 1973 with a representative of a major grain dealer and exporter, who stated that insect infestation of wheat being exported to Russia was not a problem. The wheat being shipped was relatively free of insects and the use of an FDA approved chemical pesticide, malathion, as required in the purchase contract, was effective in controlling infestation. The cost of the malathion treatment was 1/4 of one cent per bushel and could be applied without expensive or elaborate equipment. When it was suggested that treatment by radiation would cost no more than the cost of malathion, WHEAT AND POTATOES IN USA 15 the firm 's representative contended that a $200 000 to 400 000 capital outlay for radiation equipment would be prohibitive. In addition, there would be need for irradiation facilities at storage terminals located at many different ports along the Atlantic Coast and along the Southern Coast in the Gulf of M e x ico . The United States exports about 50% of its annual wheat production to countries in South America, Europe and Asia. The wheat is usually chemically treated to control insects and no change from this treatment is at present planned.

Status of wheat irradiation in the USA

Interest and activity in the US regarding disinfestation of wheat by irradiation can be summed up as follows: In August 1963 the Food and Drug Administration approved a petition, submitted by Brownell, Horne and Kretlow, for the use of gamma radiation to process wheat and wheat pro­ ducts with a dose of 20 000 to 50 000 rads for the control of insect infesta­ tion [1]. Approvals of electron beam radiation followed in 1964 and 1966. In 1967 FDA revised the regulation to change the general reference from "wheat and wheat products" to "wheat and wheat flour" in an effort to limit the application of irradiation. Irradiated foods are required to be labelled "Treated With Ionizing Radiation", or the terms, "gamma", "electron" or "X-radiation" may be substituted for ionizing as appropriate. Wholesale packages and invoices or bills of lading of bulk shipments must also include the phrase, "Do Not Irradiate Again. " The wheat petition concluded that a dose of 20 000 rads is effective in breaking the reproductive cycle of insects infesting wheat and wheat pro­ ducts; that doses of 50 000 rads or less have no detrimental effects on organoleptic, nutritional, or other qualities of bakery products made from irradiated wheat or wheat flour. To determine the dosage necessary to control insects in a commercial- scale irradiator, the US Department of Agriculture in 1968 used its bulk grain irradiator to treat 122 metric tons of wheat, heavily infested with rice weevils, lesser grain borers and flat grain beetles. Dosages of 27.4 and 41.2 krad were effective in greatly reducing all three species. However, it was noted that much of the initial insect population was destroyed by mechanical handling during treatment and that reinfestation of the wheat from outside sources occurred [2, 3]. In two more recent studies conducted by the US Army Natick Labora­ tories bakery products made from irradiated flour were rated highly satis­ factory. Two 66-ton lots of enriched bleached hard winter wheat flour were irradiated, one in 1967 and the other in 1969. After irradiation the flour was stored from one to four years at 21°C (70°F) and evaluated periodically [4 ,5 ]. The irradiated flours were shipped to military bases in the USA and overseas for use and evaluation and found to be equal in quality to the non- irradiated standard stock flour. The bread, rolls and pastry items baked with the irradiated flour were rated by the consumer to be similar to the baked products made from standard stock flour. Laboratory analysis revealed no significant difference between the irradiated and non-irradiated flour in chemical or vitamin content. 16 DEITCH

POTATOES

The harvesting and storage of potatoes in the United States has several characteristics that discourage the use of irradiation for sprout inhibition of potatoes. Included are such factors as: year-round harvest of potatoes, favorable storage climate in the northern sections of the country, properly equipped storage facilities and a system of bulk storage suited to the use of chemical sprout inhibitor. I will briefly illustrate these points.

Potato production and storage in the USA

■Potatoes are grown com m ercially in every state in the country and are harvested in one or more states every month of the year. Harvest during the winter months begins in the southern-most parts of Florida and California and proceeds northward during spring and summer. These are the early or new potatoes seldom held for storage. The fall crop, which represents about 70% of commercial production, is harvested from September to December in the northern areas. Last year (1973) potato production in the United States was over 13 million metric tons. Thus, year-round harvests provide a plentiful supply of potatoes for table use and for processing. Harvesting of potatoes is done today almost entirely by mechanized equipment that loads the potatoes in bulk directly into trucks built especially for hauling potatoes. The trucks are equipped with hoppers that unload the potatoes rapidly onto conveyors leading into bulk storage bins. The ability to harvest large volumes of potatoes in a short time has made it possible to delay harvesting for greater maturity and in general provide a more uniform and improved quality potato for storage. Practically all potatoes held for'extended storage are fall crop potatoes which are both grown and stored in the northern areas. Relatively cool temperatures for 7 to 8 months of the year, together with increased availability of proper storage facilities, have minimized spoilage and sprout­ ing. Early potatoes (those harvested in winter, spring or summer) are not usually stored or held except for relatively short periods. However, early potatoes of good quality can be stored 4 to 5 months without sprout inhibitor at 4 to 5°C (40°F) if properly cured before storage. Storage in the north is becoming less below-ground and partially below- ground storage and more above-ground storage. Increasing use of large volume, bulk handling systems have led to the construction of large single or multiple bin above-ground storage. Bins may have potatoes piled 6 metres (20 ft) high. Floor areas may range from 360 to 4500 m2 (4000 to 50 000 f t 2).

Treatment processes

The bulk system of storing potatoes is not suited for sprout inhibition by irradiation, but lends itself well to the use of the chemical CIPC (chloro-N-isopropyl-phenyl carbamate) because it can be applied in the forced air circulation system. Radiation, on the other hand, would necessitate moving the potatoes ~ transferring them into containers that could be moved through the irradiator and then back onto the potato pile. This would not only involve additional labour but the handling would be WHEAT AND POTATOES IN USA 17

likely to cause injury to some potatoes and require additional suberization, the process whereby the potato heals its cuts and bruises. Potatoes are stored immediately after harvest for suberization for 2 weeks or as long as 2 months. Because both CIPC and radiation prevent healing and thereby enhance rotting, their application as sprout inhibitors must be done after the curing period. If irradiation is to be used as a sprout inhibitor, potatoes to be treated would best be stored in pallet boxes suitable for conveyance through the irradiator. Storage in pallet boxes has certain advantages. A ton of potatoes could be moved quickly as often as necessary without handling or injury to the potatoes. Different lots or varieties of potatoes could also be separated and accessible during storage. Pallet box storage, however, has not been widely accepted. This is due largely to the high initial cost of a pallet box installation, which is estimated at 2 to times the initial cost of a good bulk storage system [6].

Potato use in the USA

The largest use of potatoes in the United States today is for processed potato products. Less potatoes are being sold for fresh table stock and more, over half, for processing. It is estimated that by 1980 two-thirds of the US potato production will be used for processing into frozen products (french fries, diced, mashed, potato puffs, au gratin, cakes, etc.), potato chips, dehydrated products (granules, flakes, slices, diced, etc. ), canned potatoes and flour and starch. The large potato processors are located mainly in the northern potato growing areas. They have indicated that they can store potatoes up to 11 months in satisfactory condition by providing proper air circulation, temperature and humidity in the storage areas and by using CIPC. Two doses of CIPC may be applied to potatoes that will be held through the summer months until the next harvest. Application is usually performed by licensed custom applicators at a cost of 3.3 cents per cwt for a single dose or 6. 6 cents for a double application. Some processors prefer to operate during the cool periods and close their plants during the summer months. Processors located in urban areas do not store large amounts of potatoes because storage space is limited. Instead they purchase from a potato broker who arranges shipment from potato packers and storage on a monthly or bi-monthly basis.

The status of potato irradiation in the USA

The use of radiation to prevent sprouting in white potatoes is of interest to the military because it uses large quantities of potatoes that are often held for a considerable length of time. As part of its work in food irradiation, US Army Natick Laboratories conducted potato research and petitioned the Food and Drug Administration for the use of irradiation to inhibit sprouting of white potatoes. FDA issued a regulation in July 1964 approving the use of cobalt-60 to provide a dose of 5000 to 10 000 rads to potatoes. The use of caesium-137 was approved in October 1964. To accommodate designs of commercial irradiators, the maximum dose was increased in November 1965 to 15 000 rads to allow for dose attenuation through potato bulk in pallet boxes holding up to a ton of potatoes. 18 DEITCH

The Army performed two production tests of irradiated potatoes — one in 1967 and one in 1969 ~ to demonstrate that irradiated potetoes can be held from one crop year to .the next and retain high quality. A quantity of 180 tons of Idaho Russet Burbank potatoes, harvested in October 1966, was irradiated during the period 9 January to 15 February 1967 and stored at 10°C (50°F) and 90% relative humidity. The potatoes were used and evaluated monthly during the period February to November 1967 at four military installations in different sections of the country and overseas (Alaska and G uam ). Reports from kitchen personnel, the soldier preference tests and veterinary reports indicated the results were generally satisfactory: (a) That the condition, quality and acceptability of the irradiated potatoes resembled those of non-irradiated potatoes customarily used; and ' (b) That the peeling and trimming losses of the irradiated potatoes were about the same as those normally experienced with non-irradiated p ota toes. Responses from personnel, participating in the tests yielded similar ratings on the hedonic scale for irradiated and non-irradiated potatoes. In the second study 11 tons of Idaho Russet Burbank potatoes were irradiated during December 1968 at a dose rate of 5000 to 15 000 rads and compared with potatoes from the same harvest that were sprout inhibited by CIPC. Evaluations conducted by the Army and Air Force during July and August 1969 indicated irradiation being equally effective with CIPC in sprout inhibition and no differences in acceptability as a result of either - trea tm en t.

The Pillsbury experiment

A comprehensive study comparing effect of gamma radiation and chemical treatment on the quality of stored potatoes for fresh market and processing usage was conducted in 1965-1967 by the Pillsbury Company under the sponsorship of the US Atomic Energy Commission. The study is significant in that the evaluations were made by potato firms who process and market potato products — dehydrated, frozen, potato chips and fresh potatoes [7]. Approximately 72 tons of potatoes from the Pontiac and Kennebec varieties harvested in October 1965 were stored for suberization. After suberization, the potatoes were randomly selected for cobalt-60 irradia­ tion, CIPC treatment and untreated control. Radiation was applied approxi­ mately one month after harvest and CIPC was applied approximately two months after harvest. MH-30 (maleic hydrazide) treatment was applied in the field to a section prior to harvest. A quantity of Russet Burbank potatoes was also included for radiation and untreated control. The potatoes were stored in pallet boxes at approximately 13°C (55°F) and 75% relative humidity with sufficient air flow to maintain optimum quality. Evaluations were made over a period of eleven months for produc­ tion of dehydrated flakes and dice, for use as potato chips, frozen french fried and for table stock potatoes. Sprouting was completely inhibited during the eleven month storage period in both the irradiated and the CIPC-treated groups. By the nine-month evaluation from time of harvest the potatoes had started to develop sweet, earthy and sprouting-type flavours and odours, together with textural WHEAT AND POTATOES IN USA 19 changes resulting in pastiness. These changes are apparently associated with the normal aging process of untreated tubers during storage but developed to a much lesser degree because of the sprout-inhibition trea tm en t. All potatoes experienced some shrinkage. The MH-30 treated potatoes developed more shrinkage than the irradiated or CIPC-treated potatoes,, while the non-irradiated were poorest in quality and were removed from the test after the seven-month evaluation. The irradiated Russet Burbank held up well through nine months frorrrharvest but were generally unsuitable for table stock after this period.

Results of boiling tests (Tables I, II)

Irradiated and CIPC-treated Kennebecs, at final withdrawal eleven months from time of harvest, were considered of good to acceptable boiling quality. The Pontiacs, irradiated and CIPC treated, were judged of acceptable boiling quality through the nine-month period. After 8 months from harvest the MH-30 treated potatoes were not satisfactory for table use because of sprouting. This occurred within 3 months for the untreated Kennebec and Pontiac potatoes. Russet Burbank potatoes were evaluated for boiling and baking quality because this variety is frequently used for both preparation methods. The irradiated potatoes performed acceptably and equally well for boiling or baking through seven months from harvest. At the nine-month évaluation the potatoes were noted for earthy, and sprouting type odours, lack of potato-like flavour, and a generally grayish translucent internal appearance. The non-irradiated Russet potatoes performed very well for boiling or baking six months from harvest, even though a few sprout nibs were, observed at the three-month period and sprouting had developed considerably during storage. Table stock acceptancy would be limited to about three' months from harvest if no sprout inhibitors are used.

Evaluation of dehydrated potato dice and flake (Table III)

The irradiated and CIPC-treated Pontiacs made acceptable dice through 10 months from time of harvest with slightly better quality indicated for the irradiated. Dice from the irradiated Kennebec potatoes were only marginally acceptable after the ninth-month test. Quality of flakes from both varieties and treatments were only marginal after 8 months.

Evaluation of frozen french fries

The companies that produced the frozen french fries received the treated and the control potatoes at intervals of 6 months to 10 months after storage from time of harvest. The potatoes were held at conditioning temperatures of 18 - 24°C (65- 75°F) with relative humidities of 7 5 to 85% for periods up to 26 days to reduce the sugar content before being processed into frozen french fries. Based solely on the results and conditions of this one experiment, the processors concluded that ionizing radiation was not the most desirable Continued on p.24. to TABLE L SUMMARY OF RESULTS OF BOILING TESTS о

W ith d ra w a l T r e a t m e n t Pontiac variety Kennebec variety p e rio d

Seven month Irrad iated No sprouts; quite sweet flavour. No sprouts; a few areas of softening and shrivelling but definitely not excessive.

CIPC No sprouts; quite sweet flavour. No sprouts; a few areas of softening and

shrivelling but definitely not excessive.

M H - 3 0 1/16 in arrested sprouts; very sweet, 1 /8 to 1/2 in arrested sprouts; slightly slightly fermented flavour; shrivelling; slightly earthy flavour;

texture not uniform - some hard and slightly mealy and pasty texture.

softer areas adjacent.

C o n tr o l 1/2 to 2 in sprouts on all; black ring 1/2 to 2 in sprouts on all pieces;

present in 50% of potatoes; extremely about lO'To internal sprouting; much H C IT E D

shrivelled appearance with very tissue breakdown - considerably dark skins; earthy odour; either softer than other treatments; mild or fermented flavour; soft and moderate shrivelling; gray-white

pasty texture; interior colour interior colour; very earthy odour rates 6 . and flavour; soft and moderately pasty texture.

Eight month Irra d ia te d No sprouts, generally very good No sprouts; very good external

appearance and firmness; very appearance. slight sweet flavour.

CIPC No sprouts; slightly shrivelled, No sprouts; slightly shrivelled;

darker and wrinkled appearance — slight surface greening; not quite not as good as irradiated sample; as good interior quality as irradiated.

softer than irradiated sam ple. MH-30 Up to 1/2 in arrested sprouts, rosette Up to 1 /2 in rosette sprouts; slight to

type; considerable interior darkened moderate skin shrivelling; interior

spots; slightly musty odour and flavour; quality satisfactory but not quite as. texture too soft; slightly shrivelled good as irradiated.

and wrinkled appearance.

N in e m o n t h Irradiated No sprouts; moderately sweet flavour; No sprouts; slightly gray and translucent slightly pasty texture. interior colour; slightly sweet and earthy odour and flavbur; slight to moderately soft and pasty but generally quite good

internal appearance.

CIPC No sprouts; moderately sweet flavour; No sprouts; white, natural colour; SA U IN POTATOES AND WHEAT

slightly pasty texture. slightly sweet flavour; slightly grainy •

t e x tu r e .

M H - 3 0 Sprouts on 80% — appear arrested, except Up to 1 /4 in rosette sprouts; slightly a few up to 3 /4 in rosette type; shrivelled exterior; slightly gray interior

moderately shrivelled appearance; colour; slight to moderately sweet

moderately sweet with slightly earthy and earthy odour and flavour; moderately flavour, slight to moderate pastiness; soft and pasty texture; very slight

very slight chem ical skin bitterness. chem ical skin bitterness.

T e n m o n th Irra d ia ted No sprouts; slightly yellow interior No sprouts, slightly watery and grayish

colour; slightly earthy and sweet appearance of starch cells; slightly odour and flavour; slightly pasty earthy sprouting-type flavour; texture

texture; slight external shrivelling. not uniform with some firmer and some pasty areas.

CIPC No sprouts; slightly yellow interior No sprouts; very slightly earthy,

colour; slightly earthy and sweet sprouting-type flavour; texture not odour and flavour; slightly pasty uniform with some firmer and some

texture; slight external shrivelling. pasty areas.

CO to TABLÉ I (cont. ) to

Withdraw al T r e a tm e n t Pontiac variety Kennebec variety p e rio d

T e n m o n t h M H -3 0 Moderate sprouting up to 1 /2 in height; Sprouting up to l/2 in height; slightly yellow interiorcolour; sweet slightly sweet and sprouting-type flavour; and sprouting-type flavour; very slight not uniform texture with some firm, some chem ical bitterness in skin. pasty areas.

Eleven month Irrad iated No sprouts; slightly earthy, sweet and No sprouting; slight to moderate earthy and sprouting-type odour and flavour; sprouting-type flavour; slightly gray colour;

slightly pasty, cohesive texture; slightly texture quite watery, pasty, chunky grayish-yellow, translucent colour and cohesive; consider unacceptable for

and appearance interior. table stock.

CIPC No sprouts; slightly earthy, sweet and No sprouting; slight to moderate earthy

sprouting-type odour and flavour; . and sprouting-type flavour; slightly H C IT E D

slightly pasty, cohesive texture. gray colour; texture quite watery, pasty, chunky and cohesive; consider

unacceptable for table stock.

Eleven month M H - 3 0 Moderate sprouting up to 1 /2 in in Several 1/2 in sprouts; internal black height; internal black spot apparent; ring and moderately gray colour; grayish-yellow interior; sweet, earthy moderately sweet, earthy, and sprouting-type odour and flavour; sprouting-type flavour; texture quite watery,

watery texture, very poor water holding pasty, chunky, and cohesive; consider

c a p a c it y . unacceptable for table stock.

Note: Data in Tables are from Pillsbury Study [7]. WHEAT AND POTATOES IN USA 23

TABLE II. SUMMARY OF RESULTS OF BAKING AND BOILING TESTS RUSSET BURBANK VARIETY

W ith d ra w a l T r e a t m e n t p erio d

Pre and post

tr e a tm e n t

Irrad iated No sprouting; generally very good

quality. 1/8 in sprouts on a few B o ile d p ie c e s . C o n tro l

Irra d ia ted

Baked C o n tr o l

S ix m o n th

Irrad iated No sprouting; some grayish-black

B o ile d interior rings present.

C o n tr o l 1/8 to 1 in sprouts on all pieces;

slightly softer than irradiated; ‘ some grayish-black interior rings

p rese n t.

Irrad iated No sprouting; slightly musty odour

and flavour; some grayish-black

Baked interior rings present.

C o n tr o l 1/8 to 1 in sprouts on all pieces;

slightly softer texture than irradiated.

Seven month

Irrad iated No sprouting B o ile d C o n tr o l Sprouts on all pieces; very shrivelled, dried-out appearance;

grayish-black interior colour.

Irrad iated No sprouting; slightly soft texture. Baked C o n tr o l Sprouts on all pieces; shrivelled, dried-out appearance; soft and spongy texture; fermented flavour.

N in e m o n th

B o ile d Irra d ia ted No sprouting; translucent interior colour; earthy and slightly sprouting-

type odour; lacks flavor; interior darkens considerably on cooling.

B aked Irra d ia te d No sprouting; translucent grayish interior colour; lacks flavour. 24 DEITCH

T A B L E II (cont. )

T r e a t m e n t C o m m e n ts p erio d

T e n m o n th

B oiled Irra d ia ted No sprouting; translucent grayish

interior colour; sweet, earthy,

sprouting-type odour; lacks flavour.

Baked Irra d ia ted No sprouting; very thick and tough

skins; translucent grayish interior

colour; sweet, slightly musty and sprouting-type odour and flavour; texture not uniform.

method for sprout inhibition for long-term storage of potatoes for french fry processing. There was more rot and breakdown in the irradiated potatoes and the colour of the fries made from the irradiated lots seemed darker than those from the potatoes treated with CIPC or MH-30.

PUBLIC ATTITUDES

To discover the attitudes of the American public toward radiation- processed foods a study sponsored by the Atomic Energy Commission was conducted in 1966 covering low-dose irradiated finfish, crabs, bananas, Hawaiian papayas and tropical mangoes [8]. It involved interviews with consumers, retailers of local fish and fruit stores, and buyers at the chain store, restaurant and institutional levels. The study surveyed 627 consumers as a representative sample of the total household population in the United States and 310 fruit and fish buyers of individual food stores, local and national supermarket chain stores and restaurants and institutions. The study revealed that very few people are aware of radiation preservation of food, but only a. small percentage stated they were definitely against irradiated foods: 11% of consumers and 8% of the food trade. After information about the process and reassurance as to safety and Government approval was provided, about 80% were willing to accept the concept. Almost half of the food trade interviewed said they would buy, sell and use irradiated foods if the Food and Drug Administration approved them. The relevancy of these data today, after 8 years of rapid changes in social values, m aybe questionable. But what is significant in the study is the fact that knowledge about food irradiation is almost non-existent. This must be rectified by wide dissemination of information on the benefits of food irradiation. Commercialization cannot take place without knowledge and acceptance by consumer, packer, wholesaler and retailer. TABLE III. SUMMARY OF RESULTS OF POTATO DICE TECHNICAL EVALUATION

W ith d r a w a l T r e a t m e n t Pontiac variety Kennebec variety p e rio d

Seven month Irra d ia ted Generally good. A few dark pieces.

CIPC Partially collapsed appearance; Slightly deeper yellow colour than

hard, tough pieces not rehydrated other treatments.

sufficiently; musty odour; quite dark

yellow colour.

M H - 3 0 Quite collapsed appearance; brown A few dark pieces. HA AD OAOS N SA U IN POTATOES AND WHEAT centres; burnt, stale odour and flavour.

C o n tro l A few black pieces; musty odour and Slightly dry and some pieces show

fla v o u r . cell collapse.

Eight month Irra d ia ted A few brown centres present; slightly Generally very good; a few brown

sweet flavour. centres noted.

CIPC Several brown centres present; generally A few dark areas; a few firm

slightly more yellow than irradiated p i e c e s . sample; slightly sweet and earthy flavour;

a few firm pieces.

M H - 3 0 1 Many brown centres present with some also Gray colour; many brown centres black; very earthy and sweet odour and and black areas; earthy odour;

flavour; a few firm pieces. blank flavour; a few firm pieces.

N in e m o n th Irra d ia ted A few small black spots present; slightly Some moderately firm pieces; earthy and sprouting-type flavour; slightly collapsed structure;

a few firm pieces. slightly yellow centres and gray

colour; slightly earthy and sprouting- type odour and flavour. T A B LE III (cont. ) to as

W ith d ra w a l T r e a t m e n t Pontiac variety Kennebec variety period

N in e m o n th CIPC Deeper yellow colour than irradiated sample; Some moderately firm pieces; slightly earthy and sprouting-type flavour; slightly collapsed structure;

a few firm pieces. slightly yellow centres and gray colour; slightly earthy and sprouting-type

odour and flavour.

M H - 3 0 Much internal blackening; strong earthy Some moderately firm pieces;

and sprouting-type odour and flavour; grayish-black streaking in pieces.

a few firm pieces.

T e n m o n th Irra d ia ted Some dark pieces; generally slightly yellow Many firm pieces; dark brown

interior; slightly earthy and sprouting- centres; strong musty flavour and H C IT E D

type flavour. o d o u r.

CIPC A few firm pieces. Slightly sprouting-type odour; a few brown centres.

M H - 3 0 Shrivelled appearance; gray colour; Several firm pieces; slightly sweet and sprouting-type odour and sweet and sprouting-type odour; flavour; a few firm pieces. a few brown centres. WHEAT AND POTATOES IN USA 27

An interesting aspect of the study was the research that specifically assessed consumer reaction to six possible label phrases: (1) "Treated with ionizing radiation" (2) "Treated with ionizing energy" (3) "Processed with ionizing radiation" (4) "Irradiated" (5) "Pasteurized with ionizing radiation" (6) "Pasteurized with ionizing energy". The reaction to the word "radiation" was the most negative. The women verbalized thoughts of the bomb, radioactivity, and a negative scared feeling about anything that employed this word. The labels evoking the most positive response were: "Pasteurized with ionizing energy" "Processed with ionizing energy". However, the Food and Drug Administration has made its determination that the word "pasteurization" involves heat treatment and it is misleading to use the word with irradiated foods. The acceptable label for irradiated foods has been defined as "Treated with ionizing or gamma irradiation" or "electron radiation" if an electron accelerator is used. Adverse reaction to the word "radiation" will have to be changed by education to reflect a process that is safe and beneficial to the consumer.

SUPPORT FOR FOOD IRRADIATION

Our National Food Irradiation Program has considerable support in the Congress of the United States. The Joint Committee on Atomic Energy, of the Congress, which is composed of 18 members from both Houses, has jurisdiction on matters pertaining to development and employment of atomic energy and has consistently supported appropriations for continuance of the food irradiation programme. While the Food and Drug Administration, as a regulatory agency, assumes a conservative position, ahighly placed spokesman has indicated that petitions on food irradiation containing sufficient evidence of safety will be approved. It is time, he remarked, that food irradiation should be given the chance to succeed or fail in the marketplace on its own merit. Earlier in the food irradiation programme commercialization in the United States was just around the corner. During the past several years the realization has grown that food irradiation's contribution of increased quality of product and benefit to health notwithstanding, commercialization will depend on a demonstration of economic advantage; and that supporting work for Food and Drug Administration approval should be based on product technology that promises com m ercial potential. Commercial potèntials will differ by country and by product. Food irradiation's com m ercial feasibility should be determined on a product basis in the socio-econom ic structure of the individual country. In the USA the com m ercial interest lies in high-dose irradiated sterilized shelf-stable meats, poultry and fish products and in low-dose irradiation of fresh meats, poultry and fish for extended shelf-life and for reduction or elimination of food-born microorganisms of public health significance. This was established by surveys conducted in 1971 and 19.72 [9,10]. ■ 28 DEITCH

In the 1971 survey sponsored by the Atomic Energy Commission twenty companies were visited — packers and retailers of meat. The purpose was to determine if the meat industry is interested in a process for extending the market life of fresh meats and poultry through the use of radiation, added phosphates and a combination of vacuum and air packaging. The process was developed by Dr. Walter Urbain and associates at Michigan State University for the purpose of enabling centralization of cutting and packaging operations. Most of the firms visited expressed interest in commercialization of the process and many of the companies said they would be willing to join in a pilot-plant operation. The 1972 study was conducted by US Army Natick Laboratories. Visited were 10 meat packers, three seafood-processing companies, two food retailers and distributors and two trade organizations. The companies were briefed on the status of the food irradiation programme, including whole­ someness, technology, economics, availability of irradiation facilities, and representative radappertized foods were demonstrated. On the basis of personal discussions and official replies by letter from 14 companies it was concluded that there is a definite industrial interest in shelf-stable, safe, high quality meat, poultry and seafood products because currently used thermal processing of shelf-stable foods has severe limitations. In addition to radappertization (radiation sterilization), the firms showed interest in low-dose irradiation for the reduction or elimination of food-born microorganisms of public health significance and for extension of the refrigerated shelf-life of the products. The Army is at present conducting large-scale 'wholesomeness' testing of irradiated sterilized beef as required by the Food and Drug Administra­ tion. This is a five-year programme involving 46 500 animals and is pro­ gressing satisfactorily. Target date for submission of the petition is 1977. On the more immediate horizon are two petitions close to submission by the Atomic Energy Commission. One is for the approval of irradiated strawberries for shelf-life extension by reducing decay due to surface mould. The other is for papayas treated with radiation to control fruit-fly infestation for export. The US Department of Agriculture and the Hawaiian fruit industry are particularly interested in approval of the papaya petition because irradiation will give good security against infestation and replace the less-desirable ethylene dibromide fumigation and vapour heat treatment [11]. Irradiation of papayas may become the first commercial application in the United States of America. Irradiation sterilized beef may follow, after 1977, to open the door to commercialization of other irradiated meats, poultry and fish products.

CONCLUSIONS

The use of irradiation for insect disinfestation of wheat or sprout inhibition of white potatoes is not likely to become com m ercial in the United States in the near future. The reason is abundance of product, efficient nation-wide distribution system, properly equipped and ample storage facilities plus areas of relatively cool climates — factors that have reduced the problem of insects in wheat and flour and sprouting in potatoes to manageable proportions that can be controlled by chemicals satisfactorily. WHEAT AND POTATOES IN USA 29

Although the need for food preservation by irradiation has had low priority,* due mainly to ample refrigerated storage and a good distribution system, the rapidly rising cost of food may accelerate adoption of food irradiation. US industry is interested in food irradiation where the technology can be profitable, where it can replace a less efficient method or contribute to product quality improvement. Perhaps implied in the US experience, and as it may apply to programmes of other nations, is the fact that food technology needs continual reassess­ ment. In the context of reassessment several questions may be raised. Is the technology as it relates to specific applications of interest to industry, and will analysis of cost versus benefits indicate a feasible commercial product? Each country must look to its own requirements in deciding the future of food irradiation.

RE FERENCES

[1] BROWNELL, L .E ., HORNE, T ., KRETLOW, W .J ., Petition for the Use of Gamma Radiation to Process

Wheat and Wheat Products for the Control of Insect Infestation, July 1962. [2] TILTON, E .W ., BROWER, J.H ., "Status.of US Department of Agriculture research on irradiation

disinfestation of grain and grain products", Radiation Preservation of Food (Proc. Symp. Bombay, 1972),

IAEA, Vienna (1973) 295.

[3] COGBURN, R.R. , TILTON, E .W ., BROWER, J.H ., Bulk-grain gamma irradiation for control of insects

infesting wheat, J. Econ. Ent. 65 3 (1972) 818.

[41 WIERBICKI, E ., Production Tests and Evaluation of Irradiated Flours, US Army Natick Labs. (1971).

[5] WIERBICKI, E ., KILLORAN, J.J., HEILIGMAN, F ., Irradiation Disinfestation of Flour, Production Tests

and Military Evaluation, US Army Natick Labs. (1973). [6] US DEPARTMENT OF AGRICULTURE, Pallet Boxes for handling and storing potatoes, Rep. AM S-455 (1961).

[7] KWIAT, E .V ., Pillsbury Company, Effect of Gamma Radiation and Chemical Treatment of Quality of

Stored Potatoes for Fresh Market and Processing Usage, Rep. CO O -1539-1 (TID 4500) (1968). [8J YANKELOVICH, D ., Cost-benefit Study of Selected Products in Atomic Energy Commission Low-dose

Food Irradiation Program, Rep. N YO -3666-1 (TID 4500) (1966). [9] URBAIN, W .M ., Excerpts from report on visits to selected packers and food retailers, Minutes of

21st meeting, Interdepartmental Com m , on Radiation Preservation of Food, US Dept. Commerce,

April 1973. [10] WIERBICKI, E ., JOSEPHSON, E .S ., Special report, meat packers, seafood processors, retailers and trade organizations surveyed for interest in radappertization, Minutes of 21st M eeting, Interdepartmental

Com m , on Radiation Preservation of Food, US Dept. Commerce, April 1973. [11] MOY, J.H ., e ta l., "Tolerance, quality and shelf-life of gamma-irradiated papaya grown in Hawaii,

Taiwan and Venezuela", Radiation Preservation of Food (Proc. Symp. Bombay, 1972), IAEA, Vienna

(1973) 375.

PREPARATIONS FOR MARKETING IRRADIATED POTATOES AND ONIONS IN THE FEDERAL REPUBLIC OF GERMANY

J. F. DIEHL Institute of Radiation Technology, Federal Research Centre for Food Preservation, Karlsruhe, Federal Republic of Germany

Abstract

PREPARATIONS FOR MARKETING IRRADIATED POTATOES AND ONIONS IN THE FEDERAL REPUBLIC OF

GERMANY.

Extensive laboratory studies, wholesomeness tests, consumer trials and experience with storage and processing of irradiated tubers on a semi-industrial scale have set the stage for the general introduction of potato irradiation in the FRG. Advantages of the process are seen primarily in the health field: irradiation as an alternative to the currently practised use of chem ical sprout inhibitors. Interest in onion irradiation is based more on econom ic considerations.

1. EARLY INTEREST IN FOOD IRRADIATION

The potential of the food irradiation process was recognized early in Germany. In 1955 the late Professor Kuprianoff, then director of the Federal Research Centre for Food Preservation at Karlsruhe, published the first report on this new preservation method in a German scientific journal [1]. At his insistence, a radiation laboratory was created at Karlsruhe in 1956. Its radiation sources consisted of a powerful X-ray machine (120 kV) equipped with a conveyor system and a van de Graaff accelerator. This laboratory became the nucleus of the Institute of Radiation Technology, which began to operate in 1966, with a linear accelerator as an additional radiation source. Nine scientists were assigned to the Food Irradiation Section of this institute. From the beginning, studies on the irradiation of potatoes were a major activity of this group. The results of these studies will be described in some detail. Efforts devoted to the radiation-preservation of onions, mushrooms and wheat were more limited and will be discussed very b r ie fly .

2. POTATOES

2.1. Benefits of irradiation

The inhibition of potato sprouting can be achieved with chem icals, such as IPC (isopropyl-N-phenylcarbamate) and CIPC (isopropyl-N- (3-chlorophenyl)-carbamate); This method is certainly less expensive than irradiation. The great advantage of irradiation Js the fact that it leaves no foreign residues. The wholesomeness of irradiated potatoes

31 32 DIEHL has been studied much more thoroughly than that of CIPC and IPC. I doubt that these chemicals, which act as inhibitors of mitosis, could pass the mutagenicity tests demanded of irradiated foods. To my knowledge, these substances have never been subjected to such tests. Another advantage of irradiation is its ability to prevent both external and internal sprouting. Chemically treated potatoes sometimes develop internal sprouts. When chips or other sliced products are made from such tubers, they have holes, resulting in a downgrading of quality. A third method of sprout inhibition is cold storage. Under household conditions this is not feasible. Adequate cold-storage facilities are not available for the large quantities of potatoes stored for commercial purposes - and it would be very expensive to build and operate them. In contrast, irradiated potatoes will not require special storage facilities. Cold-stored potatoes have increased levels of reducing sugars, which impairs their suitability for some purposes.

2.2. Technological considerations

In considering possible applications of the radiation process for sprout inhibition, we must differentiate between potatoes sold for house­ hold storage and those determined for commercial storage. In contrast to irradiation, chemical treatment does not permanently inhibit sprouting. For long-term home storage potatoes have to be powdered repeatedly with suitable chemicals. Uneven distribution is unavoidable under these circumstances, and the consumer who uses this method probably ingests considerable quantities of residues of the sprout inhibitor. Irradiation has very convincing advantages in this case — from the viewpoints of health, as well as convenience and effectiveness of the treatment. Our early interest in potato irradiation was only directed towards the use of potatoes for household storage. After extensive laboratory studies [2-5], the acceptability of irradiated potatoes was tested in a consumer trial in 1968/69 involving 34 families [6]. Irradiated and unirradiated tubers were distributed and stored in the basements of the private homes. Participants were asked periodically to evaluate the potatoes and the various meals prepared therefrom. During the first few months irradiated and unirradiated lots were rated about equally. Later, when the unirradiated tubers began to sprout, irradiated ones were rated higher. We concluded that irradiated potatoes were well suited for home s to ra g e . In recent years a pronounced change has occurred in the marketing of potatoes. Fewer families store a supply for the whole season in their homes. On the other hand, sales of industrial potato products have increased dramatically: potato crisps, prefried pommes frites, heat sterilized or frozen boiled potatoes, potato powders for the preparation of pancakes, soups etc. To be able to produce all year round, industrial potato processors depend on a continuous supply of unsprouted potatoes. The climate of Central Europe permits storage of potatoes during the winter months without major difficulty. Cold air is blown into the store­ houses, primarily during the night when outside temperatures are low enough. No sprouting occurs as long as a storage temperature of 3-4°C can be maintained. When the outside temperature rises in the spring sprouting is suppressed by blowing chemical sprout inhibitors into the Ю ТА TOES AND ONIONS IN FRG 33 storehouses as an aerosol-fog. Due to a high vapour pressure, these chemicals gradually disappear into the environment. When potatoes are to be stored for a long time (until summer) repeated applications of sprout inhibitor are necessary. Under these circumstances it appeared advisable to study the suitability of irradiated potatoes for industrial processing. A first experiment in the 1970/71 season, involving 10 t of potatoes, resulted in disappointment [7]. After 6 months of storage irradiated potatoes showed a higher amount of rot than chemically treated ones, and pommes frites and dried potatoes prepared from irradiated tubers were downgraded because of grey dis­ coloration. Irradiation was carried out with X-rays (bremsstrahlung; linear accelerator with tungsten target) at a layer thickness of 20 cm. Under these conditions the dose distribution was very uneven (Dmax : Dmin about 2.5) and some of the tubers received too high a dose. The necessity of transporting the potatoes from the harvesting area to our Institute for irradiation and transporting them back to the storehouse - distances of several hundred kilometres in both directions - was a serious handicap in this experiment. The mechanical stress of transportation, together with partial overirradiation, certainly contributed to the unsatisfactory results obtained. In the following year the conditions of irradiation were modified (layer thickness 5 cm, Dmax : D^,, about 1.2) and different potato varieties were used. Although the potatoes again had to be transported over long distances, losses due to rot were not higher in irradiated lots, when compared with chemically treated lots. Chips and heat-sterilized vacuum-packed potatoes prepared from irradiated tubers compared favourably with those prepared from chemically treated tubers [8]. It is not possible to discuss all the details here - but I may summarize our experience by saying that it is quite possible to produce high-quality products from irradiated tubers - even after long-term storage - if suitable potato varieties are chosen and if proper conditions of irradia­ tion, transportation and storage are maintained.

2.3. Attitude of health authorities

According to §4c of the German Food Law, foodstuffs may not be treated with ionizing or ultra-violet radiation unless permission has been granted. In addition to general permissions according to §4c, limited permissions for experimental purposes are possible according to §20a. Such a limited permission was granted in 1968 to allow the consumer trial mentioned above. Although an extensive animal feeding study with irradiated potatoes had been carried out with no indication of harmful effects [9] and although general clearances for irradiated potatoes existed at that time in Canada, the United States of Am erica, the Soviet Union and Israel, it took almost a full year before our Federal Ministry of Health could be convinced that irradiated potatoes were sufficiently harmless to permit a consumer trial involving 50 families (34 families actually participated). Similarly limited permissions were granted in 1970 and 1971, when chips and other products produced industrially from irradiated potatoes were to be evaluated by consumers. In all these instances the irradiated tubers or products produced therefrom were given free of charge to the partici­ pating fam ilies. 34 DIEHL

In 1973 permission was obtained to irradiate 80 tons of potatoes, to produce chips and to sell them. Unfortunately, we could not make use of this permission. No radiation source exists in the FRG that is capable of irradiating such large quantities. We had planned to borrow the French mobile irradiator IRMA for this purpose, but unexpected delays in the transportation of the heavy vehicle to Germany made it necessary to cancel the project when winter weather interfered. I think it is fair to say that the attitude of our Federal Health Ministry towards food irradiation in general and potato irradiation in particular was a rather negative one in the beginning. The growing number of clearances in other countries (Netherlands, Denmark, Spain, France, Italy) and the favourable im pression created by the very thorough whole­ someness studies carried out under the auspices of the International Project in the Field of Food Irradiation (OECD/IAEA) appear to have changed this situation. Present efforts of the European Commission to clear the way for potato irradiation in all countries of the Community will hardly be opposed. The lack of com m ercial-size radiation sources for the food industry continues to be a serious problem. The Health Ministry hesitates to give a general permission according to §4c of the Food Law as long as no radiation facilities exist that could make use of such a permission. Their argument: "The food industry is apparently not interested". On the other hand, industry will not invest into the construction of large-scale radiation facilities as long as permission for food irradiation is lacking.

2.4. Methods for the identification of irradiated potatoes

Many officials of health authorities are concerned that food irradia­ tion may not be sufficiently controlled if it is not possible to recognize irradiated foodstuffs. I do not share this concern. In contrast to food additives, which may be used illegally by some 'backyard'-manufacturers, irradiation cannot be used clandestinely. Radiation protection laws exist in all countries, which guarantee strict governmental control of all radiation facilities. It should not be difficult to oblige the operators of food irradiation plants to keep records that indicate which items have been irradiated when and at what dose level, and to label the irradiated packages accordingly. Nevertheless, in the hope that this might help to overcome the hesita­ tion of some officials, we have tried to develop methods permitting identi­ fication of irradiated foodstuffs. In the case of potatoes the problem has been solved. A very reliable but rather time-consuming histological method is available, which is based on the inability of irradiated potato tissue to form periderm cells in response to mechanical injury [10]. Another, much faster but somewhat less reliable method is based on measurements of electrical conductivity in the tubers [11].

2.5. Outlook

Chances for practical application of potato irradiation will depend mainly on two factors: POTATOES AND ONIONS IN FRG 35

(a) The future evaluation of the wholesomeness of chemical sprout inhibitors. (As long as their use is allowed, industry will prefer them as they are cheaper than irradiation.) (b) The legal permission for irradiating foodstuffs other than potatoes. (As long as only potato irradiation is allowed, radiation sources can be used only during 2 or 3 months per year. This makes irradiation very expensive. Only when other products can be irradiated during the rest of the year will food irradiation become economically interesting.)

In the meantime, we continue to gather information on:

(1) The relationship between potato variety, chemical composition, rotting tendency, and discoloration of some products made from irradiated potatoes [12]; (2) Storage behaviour of irradiated potatoes under commercial storage conditions; (3) Consumer response to irradiated potatoes and to products produced from irradiated potatoes.

We will also continue to provide information on food irradiation to the authorities and to the general public. In our experience the willingness to accept food irradiation is directly related to the information level. It will be very important to carry on public information campaigns before introducing irradiated foodstuffs in the market. I should mention at this point that our institute at Karlsruhe has not been the only one in the FRG to prepare the way for potato irradiation. Much of our knowledge is based on the extensive studies carried out by Patzold [13] and Heilinger [14] at the Agricultural Research Centre (FAL) at Brunswick.

3. ONIONS, MUSHROOMS, WHEAT

After carrying out some laboratory experiments in previous years irradiation of onions was practised on a sem i-com m ercial scale in the 1971/72 season. 400 kg were irradiated and transported to a commercial storehouse, together with 200 kg of unirradiated onions. After 8 months of storage, all of the unirradiated samples were spoiled, while 70% of the irradiated onions were still of marketable quality [8]. Under the present conditions storage losses are considerable and the price of onions goes up accordingly during the winter months. The improvement of keeping quality due to irradiation should be of interest both to the trade and to consumers. As irradiation of onions is already permitted in Canada, Italy, Israel and Thailand, we hope that our Health Ministry can be convinced at least to give a limited permission that would allow a large-scale consumer test. At a later stage we expect the clearance of onion irradiation at the level of the European Community. We have no technological experience of mushroom irradiation. We have developed a simple colour test for the identification of irradiated 36 DIEHL mushrooms [15]. Some preliminary studies concerning the effect of radia­ tion on the m icroflora of wheat and on the baking quality of wheat irra­ diated with doses between 50 krad and 1 Mrad have been carried out, with our collaboration, at the Federal Grain Research Centre at Detmold [16]. The prospects for comm ercial wheat irradiation are comparable with those for potato irradiation: as long as currently practised methods of chemical treatment are permitted, industry shows little interest in the more expensive radiation treatment. Growing concern over environmental chemicals may change this situation.

REFERENCES

[1] KUPRIANOFF, J ., Lebensmittelkonservierung durch ionisierende Beta- und Gamma-Strahlen,

Z. Lebensm. -Untersuch. -Forsch. 100 (1955) 275-303. [2] BERGER, A ., Lagerverhalten rontgenbestrahlter Kartoffeln, Atompraxis 6_ (1960) 301-8.

[3] BERGER, A ., Einfluss weicher Rontgenstrahlen und mechanischer Effekte auf das Keimen von

Kartoffeln, Eur. Potato J. 4 (1961) 211-23. [4] BERGER, A ., HANSEN, H ., Zur Qualitâtserhaltung dlinnschaliger Kartoffeln durch Rontgenstrahlen niederer Dosis, Z. Lebensm. -Untersuch. -Forsch. 117 (1962) 215-25. [5] HANSEN, H ., GRÜNEWALD, T h ,, Die Abhangigkeit der zur Keimhemmung erforderlichen

Strahlendosis von der Kartoffelsorte, Dtsch, Lebensm. Rundsch. 60_ (1964) 50-1.

[6] GRÜNEWALD, T h ., Verbrauchertest mit bedtrahlten Kartoffeln, Ber. Bundesforschungsanstalt fur Lebensmittelfrischhaltung, BFL 1/1970, 48 p.

[7] PENNER, H ., et a l., Untersuchung der industriellen Verarbeitbarkeit bestrahlter Kartoffeln,

Ber. Bundesforschungsanstalt für Lebensmittelfrischhaltung, BFL 2/1972, 50 p.

[8] PENNER, H ., e ta l., Untersuchung der industriellen Verarbeitbarkeit und des Lagerverhaltens

bestrahlter Kartoffeln und Zwiebeln, Ber. Bundesforschungsanstalt für Lebensmittelfrischhaltung, BFL 4/1972, 37 p.

[9] LANG, K ., BASSLER, K. H ., "Nutritional value of irradiated potatoes ", Food Irradiation (Proc. Symp. Karlsruhe, 1966), IAEA, Vienna (1966) 167-69.

[10] PENNER, H ., Histologischer Nachweis einer erfolgten Bestrahlung von Kartoffeln, Z. Lebensm.- Untersuch. -Forsch. 144 (1970) 99-101.

[11] SCHERZ, H ., Conductivity Measurements as a Method for Differentiation between Irradiated and Non-irradiated Potatoes, Rep. EUR 4953 (1973) 24 pp.

[12] RUMPF, G ., Gas chromatographic studies on the suitability of irradiated potatoes for storage and processing, Potato Res. 16 (1973) 296-301.

[13] PXTZOLD, C ., "Vor- und Nachteile verschiedener Kartoffelkeimhemmungsverfahren einschliesslich

Strahlungsanwendung ", Die Bestrahlung von Kartoffeln, Kommission der Europaischen Gemeinschaften, Informationshefte des Büro Eurisotop 45 (1970) 8-35.

[14] HEILINGER, F ., "Einfluss von Rontgenstrahlen auf Keimung und Kohlenhydratstoffwechsel der

Kartoffelknolle", Die Bestrahlung von Kartoffeln, Kommission der Europaischen Gemeinschaften, Informationshefte des Büro Eurisotop 45 (1970) 36-62,

[15] MÜNZNER, R ., Nachweis einer Strahlenbehandlung bei Champignons, Z. Lebensm.-Untersuch. - Forsch. 151 (1973) 318-19.

[16] OCKER, H .D ., SPICHER, G ., Auswirkung einer Bestrahlung von Weizen mit Elektronen auf die Mikroflora, Getreide Mehl 20 (1970) 50, PRESENT STATUS AND PROSPECTS FOR THE COMMERCIALIZATION IN HUNGARY OF IRRADIATED FOOD ITEMS FOR HUMAN CONSUMPTION

J. FARKAS Central Food Research Institute, Budapest, Hungary

Abstract

PRESENT STATUS AND PROSPECTS FOR THE COMMERCIALIZATION IN HUNGARY OF IRRADIATED FOOD

ITEMS FOR HUMAN CONSUMPTION. The paper summarizes research in Hungary on the irradiation of potatoes, onions and mushrooms and the present status of approval by the health authorities. The results of two econom ic feasibility studies, based on the assumption of the establishment of irradiation plants in Budapest, are described. The factors hindering com mercialization of radiation techniques in Hungary and the conditions of the acceleration of this process at home and abroad are discussed.

Research in the field of food irradiation has been in progress in Hungary for 15 years. The centre of research in this field has been the Central Food Research Institute, which possesses an RH-gamma- 30 type laboratory, self-shielded 60Co gamma radiation source of at present about 15 kCi activity and a pilot plant for food irradiation. The panoramic gamma source of the latter, provided with storage pond, contains at present a load of about 60 kCi 6QCo. The materials to be irradiated are moved through the irradiation chamber by an overhead conveyor. The speed of the conveyor may be programmed over a wide range. Of the irradiation techniques that have been granted authorization from the public health aspect in one or several countries, only wheat disinfestation has not been studied in Hungary. The reason for this is that the technical and economic feasibility of wheat disinfestation has been subjected to thorough investigation in a number of countries, in particular in the USA and Canada. The reproduction of experiments carried out elsewhere does not seem necessary because the results established abroad are considered valid for Hungarian conditions. However, the inhibition of sprouting in potatoes and onions and the retardation of changes in Agaricus bisporus after picking have been thoroughly investigated. In the following a short review is given of the experience gained in this field in Hungary and on the present status of the authorization of these techniques from the public health aspect. The factors hindering the industrial realization of these irradiation techniques in Hungary and prospects for the future are also discussed.

37 38 FARRAS

1. EXPERIENCE GAINED IN RELATION TO THE TECHNICAL FEASIBILITY OF IRRADIATION TECHNIQUES

1.1. Inhibition of the sprouting of potatoes

The yearly average loss on storage of potatoes amounts to 8-12% of the total quantity available, which is 160-300 thousand tonnes of potatoes per year [1,2]. The storage period of potatoes in Hungary lasts from the middle of August to the middle of June the following year. The trade norms permit a loss of 13.3% for outdoor storage between January and the end of May and 15.6% for cellar storage. If the storage period is extended beyond May, a further loss of 5.7 or 6.3% may be accounted for. Thus the total loss amounts to about 20% of the original weight. One of the largest firm s engaged in the inland marketing of fruit and vegetables, Zoldért, expects a loss of 5-15%, but a loss of 40-48% has been experienced in exceptionally bad years. Potato irradiation experiments, performed between 1963 and 1970 in Hungary, have shown that the sprouting of potatoes during storage may be retarded through gamma radiation doses of 5-15 krad [3-6]. It was found that the inhibitory effect was equally successful for cellar storage at 5-10°C, in cases at room temperature, or for traditional storage in clamps. No substantial difference in the dose requirement for the various potato varieties investigated was observed. In conformity with experience gained abroad [7], the radiation treatment of potatoes was found effective even when carried out several months after harvesting. Sprouting was totally inhibited when potatoes were radiation treated at the beginning of April with a dose of 10 krad, though this preceded sprouting only by about two to three weeks [8]. In this experiment the radiation-treated potatoes, subsequently stored at room temperature, yielded about 30% more hand-peeled potato than unirradiated samples of the same variety. Observations on the changes in sugar content of potatoes made by foreign authors [9-11] were confirmed in Hungarian experiments. The reducing sugar and saccharose contents of irradiated potatoes were found to increase temporarily upon treatment, but after storage for several months by the beginning of spring the sugar content became equal to that of untreated potatoes or diminished to an even lower level [6]. Preliminary experiments carried out at the National Institute for Nutrition [12] have shown a reduced solanine-forming capacity in irradiated potatoes. In accordance with experience gained abroad, it was observed at this Institute that irradiation reduced the vitamin С content of potatoes by about 20%; however, during storage the vitamin С content of irradiated potatoes decreased at a slower rate than that of untreated ones and after a storage period of about 5 months the vitamin С content of treated and untreated potatoes did not differ [13]. The m icrobiological stability of potatoes was also investigated in Hungary. Figure 1 was plotted using the results of experiments performed with five potato varieties by Sárvári et al.[6]. The figure shows the propor­ tion of m icrobial spoilage in potato lots irradiated in November 1968 and stored for 6 months till the beginning of May 1969, and the frequency distribution of storage diseases by microorganisms. Of the varieties tested, Gülbaba is that cultivated over the largest area. The other varieties were bred at the Potato Research Division of the Agri- COMMERCIALIZATION IN HUNGARY 39 cultural University, Keszthely, Hungary, and are less susceptible to virus diseases than Gülbaba [14]. As seen from Fig.l, there was a substantial difference in the suscepti­ bility of the varieties tested to microbial spoilage. Radiation doses of 10 and 15 krad not only increased the susceptibility to spoilage of the variety shown, К 59838. Variety К 630 proved to be particularly liable to spoilage and most unsuitable for storage. As can be seen, rotting was caused mainly by Fusaria. Spoilage caused by Phytophtora infestans played a less important part. Bacterial rot was limited mostly to damaged, tubers, prone to secondary infection. The appearance of Erwinia atroseptica was only s p o ra d ic .

BACTERIAL ROT AFTER \ FUSARIUM ROT □WOUNDING

Erwinia atroseptica j Phytophtora infestans

%

30

IN EARTH-COVERED 20 STACKS

10

^ —» 0 5 10 15 0 5 10 15 0 5 10 15 krad

К 5 5 0 К 59.636 К 5 9 0 К 6 3 0 GULBABA

F IG .l. Frequency distribution of diseases causing spoilage in potatoes during the six-m onths’ storage period.

Data taken from Ref. [6 ]. 40 FARRAS

□ WEIGHT OF SPROUTS

g WEIGHT-LOSS AND SPOILAGE

STORED 5 MONTHS I и n l i i April I IN WOODEN CRATES AT 7-11’ C UNDER 70 -95% RH

г ю u h

0 5 1015 0 5 1015 0 5 1015 krad

FIG. 2. Storage losses derived from weight loss, spoilage and the weight of sprouts as a function of the radiation dose and storage tim e. Data taken from R ef.[6]. COMMERCIALIZATION IN HUNGARY 41

Similar results have been obtained in recent experiments with potatoes irradiated at the beginning of the storage season (August) [15]. After a 3-month storage period subsequent to radiation treatment the number of Fusarium -infected tubers in the lot treated with 5-10 krad was about three to four times that in the control lot. Infection with Phytophtora and Alternaría was not affected by irradiation. These observations confirm reports published much earlier of a lowered resistance to m icrobial infection in radiation-treated potatoes (e.g. Ref.[16]). This necessitates very careful handling of the potatoes to be irradiated before, during and after the treatment to avoid strong mechanical impact that could cause damage and open a path for m icrobes. It is of interest that in case of-irradiation in the spring [8] spoilage in potatoes vibrated for 20 minutes was significantly increased during the subsequent two months, but not m ore extensively than in the untreated control. The total loss in storage is composed of loss of weight, microbial spoilage and the weight of sprouts. The proportion of each component in the gross loss depends on the variety, the storage conditions, the time of storage and the radiation dose. The storage-loss reducing effect of irradiation was mainly observable when storage was extended into spring or early summer, since irradiation prevented losses from sprouting and intensive shrivelling during this period. Figure 2 shows the results of experiments conducted during the storage season 1968/1969 [6], giving the weight losses of five potato varieties as a function of storage time and radiation dose. The figure indicates within the total loss as related to the original weight, the weight loss, the proportion of decayed tubers unsuitable for use and the loss manifested in the weight of sprouts. As seen, 6 months of outdoor storage in clamps at lower tempera­ ture and with less ventilation were required to reach the gross loss level reached in 3 months by potatoes stored in wood cases in a cellar. Sprouting started during December-January. Without considering variety К 630, which proved to be unsuitable for storage, gross losses worked out as follows:

Untreated potatoes stored in clamp 8-11%, in cellar 18-32% Potatoes given 5 krad stored in clamp 4-7%, in cellar 13-15% Potatoes given 10 krad stored in clamp 3-6%, in cellar 9-14% Potatoes given 15 krad stored in clamp 1-4%, in cellar 10-13%.

These results show that the average storage loss was reduced by about 10% in case of cellar storage and by about 5% in case of clamp storage (from ábout 23 to 13% and from about 9 to 4%, respectively).

1.2. Inhibition by irradiation of sprouting in onions

The average loss on storage of onions in Hungary amounts to about 10% [1]. Experiments to investigate inhibition of sprouting in onions were started in 1966 [17] and followed up subsequently [18, 19]. These studies support the observation first published by Mullins and Burr [20] that the efficiency of sprout inhibition in onions by irradiation, in contrast to that in potatoes, depends largely on the period of time elapsing between harvesting and irradiation. Therefore the radiation treatment of onions should be performed within 6 weeks after harvesting. 42 FARKAS

M AKÔl STRIôUNOVSZKU

FIG .3. Weight proportion of onions of com mercial value in lots as a function of (a) radiation dose, (b) irradiation time, and (c) storage period [18]. COMMERCIALIZATION IN HUNGARY 43

In the experiments conducted during the storage season 1970/1971 the generally cultivated Makó variety, grown from seed-onions, and the Strigunovszkij variety, of one year vegetative period and grown from seed, were irradiated with 0, 5,.10 and 15 krad and stored. Storage was carried out at 4- 10°C and 78-85% relative humidity promoted sprouting and moulding. Complete inhibition of sprouting was not achieved by the radiation treat­ ment performed 2 weeks after harvesting; however, the proportion of sprouted onions was substantially reduced by treatment with 5 krad, the treatment found most successful. The sprouting of the Makó variety, that more inclined to sprouting, was reduced from 85 to 14% by 5 krad 2 weeks after picking, according to the last evaluation in May-June. Sprouting of the lots treated 6, 9 and 20 weeks after harvesting amounted to 53, 67 and 75%, respectively. We were surprised to discover that radiation doses of 10 and 15 krad were not more effective in inhibiting sprouting than 5 krad, on the contrary their, effect was consistently somewhat lower. The inhibitory effect of irradiation did not manifest itself in the total inhibition of sprouting, but rather in the inhibition of growth of the sprouts, which hardly developed at all. M icrobial spoilage was not promoted by radiation treatment, the Makó variety suffering lower spoilage loss when radiation treated than when u ntreated. Since even those onions that were otherwise unspoiled were useless due to sprouting and consequent complete withering, only sound, unsprouted onions were considered to be of commercial value. The weight-proportion of onions of com m ercial value as a function of radiation dose and time, and of storage time is shown in Fig.3. When the storage was extended to the end of May, by the beginning of June the gross storage loss of onions irradiated 2 or 5 weeks after harvesting with 5 krad amounted to about 35-40% of the loss in untreated samples. Calculating with a gross loss on storage of about 20%, this type of treatment resulted in an increase in storage life of about 6 weeks.

1.3. Retardation of changes in Agaricus bisporus after picking by irradiation

Agaricus bisporus is the most significant of the mushrooms cultivated in Hungary. More than 250 000 m2 are under mushroom cultivation and the greater part of this area is cultivated by a single enterprise. The yield per year is more than 1300 tonnes [21]. However, the great problem of mushroom cultivation is the rapid ageing and decrease in quality of the picked mushrooms, which has a very limiting effect on the time and space of marketing. In 1967, soon after the publication of the first investigations into the radurization of mushrooms [22, 23], research in this field was started at the Central Food Research Institute [24, 25]. In the course of these experiments it was established that gamma radiation inhibited the opening of the caps, the elongation of the stem, and moulding and reduced the browning during storage. Thus, in the case of storage at 5-8°C and 70-90% relative humidity the storage stability of mushrooms was increased from 3 to 9 days by a treat­ ment with 25-krad gamma radiation. To extend the storage life of mushrooms at higher temperatures much higher radiation doses were required (100-300 krad). At 16-18°C and about 65% relative humidity a radiation 44 FARKAS

FIG.4. Mushrooms given 0, 25, 100 and 300 krad after 10 days ’ storage at 5 - 8°C and 70 - 90 °jo r e la tiv e humidity [24].

t

20V. 30% 40% SLIT ~ WIDTH

FIG. 5. Effect of ionizing radiations on the increase in storage period of mushrooms till reaching 20, 30 and 4 0 % opening of the caps for mushrooms picked at two stages of maturity: 1. half-ripe; 2. ripe [24]. COMMERCIALIZATION IN HUNGARY 45

dose of 300 krad increased the storage life of mushrooms from 1 to 3 days. In this case the only limiting factor was advancing weight loss, because on the basis of other quality characteristics the mushrooms could be stored for 6 d a ys. Figure 4 shows mushrooms after 10 days' storage at 5-8°C and 70-90% relative humidity, treated with 0, 25, 100 and 300 krad [24, 25]. The organoleptic quality of the mushroom was not reduced by radiation treatment, indeed, the treatment helped to retain aroma and flavour substances. The efficiency of irradiation depended on the maturity of the mushroom at picking. As seen in Fig.5, the effect was more extensive when not quite ripe mushrooms were picked, in the stage of 'export maturity'. The effectiveness of irradiation was not reduced even if it was not carried out immediately upon picking, but after cold storage for 2 days. This fact would permit of the irradiation of mushrooms in a radiation facility some distance from the place of cultivation. More detailed further experiments supported the above results [26-28].

2. STATUS OF LEGISLATION AND CONSUMER TRIALS

On the basis of the promising research results in December 1969 the Hungarian Ministry of Public Health granted permission to conduct consumer trials on 5 tonnes of potatoes irradiated with 10 krad for the first time in Hungary. The trial consisted of giving equal amounts of treated and untreated potatoes to institutional catering in one of the high schools, or distributing to families on the basis of voluntary application for further storage and home use. In the spring these potatoes were prepared for consumption in various ways and the high school students and the participating fam ilies were asked to evaluate the dishes on special forms. The consumer trial was concluded with good results [29]. The publications on the wholesomeness testing of potatoes found in the technical literature were summarized at the Central Food Research Institute in 1971 [30]. Taking into account these data and the common application of the vegetable-marketing enterprise Zôldért and the Research Institute, the Ministry of Agriculture and Food, by mutual agreement with the Ministry of Public Health, approved of the irradiation of 200 tonnes of potatoes at a dose level not higher than 15 krad for marketing during 1972. Because of delay in granting approval, only 50 tonnes were irradiated in January 1972. These potatoes were stored in bulk in the cellar of the pilot plant of the Institute parallel with an equal quantity of untreated potatoes serving as control. The two experimental batches were marketed by Zôldért in one of the large stalls at a market place in Budapest in May 1972. The price of the irradiated potatoes was the same as that of potatoes sold in the state retail trade. The radiation sprout-inhibition treatment was declared on the labels. The marketing trial showed that consumers had no aversion to buying radiation- treated potatoes. The Hungarian authorities approved of the irradiation of 10 000 tonnes potatoes during the storage season of 1973/1974. So far this approval has only partially been made use of. Commissioned by the Hungarian Refriger­ ation Industry, the pilot plant of the Institute irradiated with an average dose of 8 krad a total of 40 tonnes consisting of two varieties. These and the 46 FARRAS control batches are stored and will be processed by the refrigeration industry into pommes frites for the home market during the spring of 1974. The aim of this trial is to establish the suitability of radiation-treated potatoes for processing by the refrigeration industry. Zôldért planned the irradiation of 300 - 1000 tonnes of potatoes during autumn 1973. The intention was to treat the potatoes in one of its own potato-storage facilities with a transportable radiation source До be constructed during 1973, and not at the pilot plant of the Institute. The irradiation equip­ ment was not ready for operation at the time intended and therefore the treatment was postponed to the next year. Approval for the irradiation treatment of onions for human consumption to inhibit sprouting on a pilot-plant scale was first requested in 1973. The competent health authority approved of the irradiation of 20 tonnes of onions during 1973, on condition, however, that the irradiated onions were mixed prior to marketing with a four-fold amount of untreated onions. Five tonnes of onions were treated at our pilot plant in October 1973 with an average dose of 6 krad. To establish the suitability of irradiated onions to processing and losses on storage, peeling, etc. and their quality, this amount of treated onions will be dehydrated together with the same amount of untreated onions. This product will be marketed during 1974 under the conditions of the a p p rov a l. So far no application has been made for permission to market irradiated Agaricus bisporus nor have marketing trials been conducted. As can be seen from the foregoing, the competent Hungarian health authorities have not adopted a negative attitude to the radiation treatment of food. They would be willing to approve the marketing of irradiated foodstuffs on the basis of toxicological tests performed abroad if detailed documentation of investigations were available and the successful application on an industrial scale of food items hitherto approved in other countries could be demonstrated However, this has not been possible so far.

3. PROBLEMS OF ECONOMIC FEASIBILITY

Several investigations have been conducted into the economic feasibility of the food irradiation processes in question. One of these studies analysed the expenditures of setting up potato-irradiation equipment [31], another estimated the economic feasibility of sprout inhibition in both potatoes and onions [32], while two studies made cost-benefit analyses of multipurpose radiation facilities [21, 33]. These investigations,were based on the assump­ tion of the establishment of 60Co gamma-radiation sources. Kiss et al. [21] suggested the establishment of a gamma-radiation source of 200 kCi for the treatment of plant produce. This gamma-irradiation plant would, not be an independent establishment but would function within the organizational and administrative framework of an existing fruit and vegetable marketing enterprise. The goods to be irradiated would be placed in bulk into containers made of wooden laths of about 0.5 m3 capacity, folded when empty. Depending on the product density, these containers could hold 100-300 kg of the goods either in bulk (potatoes, onions) or in smaller cases (mushrooms, etc.). The inhomogeneity of dose would not exceed ± 25%. TABLE I. MODEL IRRADIATION PROGRAMME: TIME REQUIREMENT OF GOODS TO BE IRRADIATED (hours work)

Ite m Jan . F e b . M a rch A p r il M a y June July A u g . S e p . O c t . N o v . D e c . Yearly total ALI ON I HUNGARY R A G N U H IN N IO T A IZ L IA C R E M M O C P o ta to ------50 1 5 0 1 5 0 3 5 0

O n io n ------1 00 1 0 0 - - 2 0 0

M u sh ro o m 1 00 1 00 1 0 0 1 0 0 - - - 1 0 0 50 50 50 5 0 7 0 0

Straw b erry - - - - 7 2 0 7 2 0 3 6 0 - - - - - 1 8 0 0

T o m a t o ------1 0 0 1 0 0 5 0 ■ - - 2 5 0

Vegetables, peeled and sliced 1 00 1 00 1 0 0 1 0 0 - - - 1 0 0 50 50 1 0 0 1 0 0 8 00

Ground paprika or mixed seasoning 1 00 1 0 0 1 0 0 1 0 0 ------4 0 0

Total of workhours 3 0 0 3 0 0 3 0 0 3 0 0 7 20 7 20 3 6 0 3 0 0 3 0 0 3 0 0 3 0 0 3 0 0 4 5 0 0

Number of shifts 2 2 2 2 4 4 4 a 2 2 2 2 2 2 . 3

Working days 25 2 5 2 5 2 5 30 30 1 5 2 5 2 5 2 5 2 5 2 5 3 0 0

a From July 1 to 15; between July 15 and 31: planned preventive maintenance. 4^ СО

TABLE II. MODEL IRRADIATION PROGRAMME: QUANTITY OF PRODUCE TOBE IRRADIATED (tonnes)

D o se T h ro u g h p u t Item Jan. F e b . M a rch A p r il M a y June July A u g . S e p . O c t . N o v . D e c . Yearly total (k rad ) ( t /h )

P o ta to 10 21 ------1 0 5 0 3 1 5 0 3 1 5 0 7 3 5 0

O n io n 10 21 ------2 1 0 0 2 1 0 0 - - 4 2 0 0

M u sh ro o m 2 5 0 0 . 8 5 8 5 85 8 5 8 5 - - - 8 5 4 2 4 2 4 3 4 3 5 9 5 S A K R A F

Vegetables, 2 5 0 0 . 8 5 8 5 85 8 5 8 5 - - - 8 5 4 2 4 3 8 5 85 6 8 0 peeled and sliced

S traw berry 2 5 0 0 . 8 5 - - - - 6 1 0 6 1 0 3 1 0 - - - - - 1 5 3 0

T o m a t o 2 5 0 0 . 8 5 ------' - 85 85 4 0 - - 2 1 0

Ground paprika 0 . 2 1 21 84 1 0 0 0 21 21 21 ~ - - - " “ " or mixed seasoning

T o t a l _ 1 91 1 91 1 91 1 9 1 6 1 0 6 1 0 3 1 0 2 5 5 2 2 6 9 3 2 7 5 3 2 7 8 3 2 7 8 1 4 6 4 9 COMMERCIALIZATION IN HUNGARY 49

TABLE III. OPERATIONAL COSTS OF AN IRRADIATION PLANT OF 200 kCi ACTIVITY

Operational costs for 4500 working hours C o st it e m s r. • (1000 Forints)

Amortization

3% per year on 4800 x 103 Ft (buildings) 1 4 4

15% per year on4800 x 103 Ft (equipment) 7 2 0

Radiation source replenishment, 12% per annum 1 1 2 8

Expenses pertinent to dose requirement 1 9 9 2

Costs of power requirement (1% of the investment costs

per 4000 working hours) 1 0 8

W a g e s

4 men per shift; 2500 h/a; at 15 Ft 3 3 7 T a x e s , 2 5 % 8 4

Overhead expenses, 100% of wages 3 3 7

Expenses related to the volume of produce 8 6 6

Total operational expenditure 2 8 5 8

Division of expenses based on the model programme of irradiation:

Irradiation expenses per 1 ton of potatoes or onions ’ 8 0 . 1 0 Ft

Total cost of irradiation per 1 ton of mushrooms,

strawberries, tomatoes, peeled and sliced vegetables 5 8 1 . 2 0 Ft

Total cost of irradiation per 1 ton of ground paprika

or mixed seasoning 2 1 4 9 . 2 0 Ft

The products to be treated, their distribution in time and the doses to be applied are shown in Tables 1 and II. In preparing these tables the product- volumes to be irradiated per hour were calculated on the basis of dose requirement, the activity of the source, the radiation efficiency factor (assumed to be 0.2 in this case) and the throughput capacity of the plant [34]. The radiation efficiency factors for package-type equipment was taken into account with values about 0.20 - 0.25, based on data taken from the literature [35, 36]. On a basis of 300 workdays and operation in two shifts with an annual operating time of 4500 hours, the operating costs of the irradiation plant would be as shown in Table III. In calculating these data the total cost of building and equipment investment was assumed to amount to 9.6 million forints (Ft) and the purchase of radiation sources to 9.4 million Ft (1 C i= l rouble plus packaging, transport and loading costs). ел о

TABLE IV. ECONOMIC RESULT OF IRRADIATION CALCULATED FOR THE MODEL PROJECT

Irradiation cost Reduction of losses {°]o) or U n it p ric e Ite m Per to ta l improvement of quality o f p ro d u ce V a lu e o f °Jo reduction of C le a r resu lt o f Q u a n tity D ose Per unit quantity to be irradiated losses irradiation ( t /a ) (krad) (Ft/t) (103 Ft/a) ( F t /t ) ( 1 0 3 F t /t ) ( 1 0 3 F t /a )

P otato 7 3 5 0 10 8 0 .1 0 590 8 3 6 0 0 2 1 0 0 + 1 5 1 0

O n ion 4 2 0 0 10 8 0 .1 0 3 3 7 5 4 3 0 0 9 0 5 + 5 6 8

M u sh ro o m 5 9 5 2 5 0 5 8 1 .2 0 3 4 4 Retaining 1st class 4 0 0 0 0 4 8 0 + 1 3 6 S A K R A F quality (+ 1 0 % ). A ssu m in g 2 0 of the

total to be 2nd class 3 6 0 0 0

Vegetables, peeled and 6 8 0 2 50 5 8 1 .2 0 3 9 5 Retaining 1st class 9 6 0 0 6 5 3 + 2 5 8

s lic e d q u a lity (+ lO^o)

Straw berry 1 5 3 0 2 50 5 8 1 .2 0 890 10 1 3 5 0 0 2 0 6 0 + 1 1 7 0

T o m a t o 2 1 0 2 50 5 8 1 .2 0 1 2 2 Retaining 1st class 5 0 0 0 2 1 0 + 88 quality (+ 20 %

Paprika, mixed seasoning 84 1 0 0 0 2 1 4 9 . 2 0 1 8 0 Extra export price + 10% 4 0 0 0 0 3 3 6 + 1 56

T o t a l 1 4 6 4 9 _ 2 8 58 . - 6 7 4 4 + 3 8 8 6 COMMERCIALIZATION IN HUNGARY 51

Thus the economic result of the establishment of the radiation source, based on the operating model, would be as seen in Table IV. The operating cost of 2.86 million Ft for the irradiation of the annual amount of 15 000 tonnes of produce could be confronted with a surplus receipt of about 6.74 million Ft, which would mean about 4 million Ft profit per annum. The recovery of expenses may be even more advantageous with optimalization of the irradi­ ation programme. In suggesting the radiation treatment of potatoes and onions in Budapest, the largest consumer centre, the following considerations were taken into account [18]: About 40-50 thousand tonnes of potatoes and 4-5 thousand tonnes of onions per year are stored in Budapest. Since the desirable irradiation periods of these two products do not overlap (for potatoes at least two weeks after harvesting till about February, for onions immediately after harvesting till at most within 6 weeks), the onions could be treated first and the potatoes afterwards. When planning the capacity it would be sufficient to take the potatoes into consideration because they represent the larger volume. The irradiation plant was considered to be of optimum capacity when the investment costs (B) could be recovered in the shortest possible time through the difference between the value expressed in Ft (Dp) of reduction

TABLE V. TECHNICAL-ECONOMIC PARAMETERS FOR AN IRRADIATION PLANT FOR POTATOES AND ONIONS TO BE. BUILT IN BUDAPEST

Irradiating potatoes only:

Total amount to be irradiated 22 x 10s t/a

Operation time 1640 working hours Activity of the source A = 71 kCi 60Co Investment expenses В = 1 6 . 6 X 1 0 6 Ft

Operation costs (irradiation) U = 2 . 3 5 X 1 0 6 Ft/a Reduction in storage losses D = 1.76 x 10st/a (8%)

Ft value of reduction of losses Dp = 4.37 X 10® Ft/a Throughput of the irradiation plant К = 13 t / h Specific operational costs u = 1 0 6 . 8 F t /t

Recovery time of investment — ^ — = 8 . 2 a

If prior to the potato-irradiation period 5520 t of onions are irradiated at the capacity dimensioned for potatoes, assuming a reduction of losses of 494 t/а, the changes caused by

irradiation of onions would be

AU = llxlO 3 Ft/a

AD = 1.24x 10s Ft/a

Recovery time : сл to

TABLE VI. HUNGARIAN COST ESTIMATES OF VEGETABLE IRRADIATION

S o u rce Total operating cost Unit cost as R a d ia tio n U n it c o s t Irradiation strength Total investment p er y e a r per cent of e f f i c i e n c y Plant utilization T h ro u g h p u t p la n t 60C o a v e ra g e fa c to r (k C i) f h /a ) ( t / a ) (103 Ft) (103 US $) (103 Ft) flO3 US $) (Ft/t) ($/t) retail prices

1 5 0 0 0 S A K R A F 4 5 0 0 in c lu d in g

Multipurpose 2 0 0 0 . 2 0 among others 1 9 0 0 0 760 2 8 5 8 1 4 2 8 0 . 1 3 . 2 0 p : 2 . 2 irradiator [21] 350 h for potatoes 7400 t potatoes p & 0 p & о o : 1 . 9 200 h for onions 4200 t onions 5 8 1 2 3 . 2 5 m : 1 . 4 5

700 h for mushrooms 595 t mushrooms m u sh r. m u sh r.

P o ta to 71 0 . 2 5 1 6 4 0 2 2 0 0 0 1 6 6 0 0 6 6 3 2 3 5 0 9 4 1 0 6 . 8 4 . 2 7 3 . 0 irradiator [32]

V e g e t a b le 71 0 . 2 5 1 8 5 3 22 000 t potatoes 1 6 6 0 0 6 6 3 2 3 6 0 9 4 . 5 86 3 . 4 4 p : 2 . 4 irradiator [32] 5 520 t onions o : 2 . 0 COMMERCIALIZATION IN HUNGARY 53 in potato and onion losses (D) achieved by irradiation and the operational costs of the plant (U). In the calculations the considerations of Kukacka and Manowitz [35], Urbain [37], del Val Cob and de la Cruz Castillo [38] were followed. The efficiency factor of 0.25 was used and 42 Ft/C i unit cost was calculated for the purchase of the radiation source. The result obtained by calculations, a detailed account of which cannot be given here, has shown that the optimum recovery time will only be achieved if the potato quantity marketed between the 4th and 10th month of storage (22 thousand tonnes) was radiation treated. As shown by the data summarized in Tables V and VI, for the irradiation of potatoes and onions in Budapest a radiation source containing about 70 kCi would be required. The investment expenses of the plant were calculated to be about 16.6 million Ft. The irradiation expenses, if only 22 thousand tonnes of potatoes were irradiated, would amount to 2.35 million Ft/a, the reduction in losses achieved by irradiation to 4.37 million Ft/ a, and the amount of potatoes saved to 1.67 thousand t/a. The invested costs could be recovered in 8.2 years. If, prior to the potato treatment season, about 5500 tons of onions were also irradiated and assuming the amount of onion saved from spoilage to be 494 t/a, the irradiation costs would be 2.36 million Ft/a and the reduction of losses 5.61 million Ft/a. The investment costs could be recovered in this case in 5.1 years. Recovery in 5 years, or even 8 years is acceptable for a facility for the purpose of storage. The investment recovery index is insensitive to the interests of the national economy, such as the prevention of losses of agricultural produce. It does not respond even to such extreme situations (a) when, e.g., a staple food has to be imported, or (b) when demand for the food cannot be met because large quantities of produce perish due to inadequate storage. In calculating the recovery index a capacity utilization of about 30% per annum was taken into consideration. The recovery of the irradiation plant is favourable in comparison with other investments in the food industries of a seasonal character (canning industry, sugar industry, etc.). If the irradiation plant can be utilized as a multipurpose package-irradiation plant, the economic indices become even more favourable. To be able to determine the place and extent of irradiation of potatoes and onions marketed outside Budapest and its immediate surroundings, the costs and other consequences of transport must be taken into consideration. This is a question of transport programming and will be attended to in due c o u r s e .

4. FACTORS SLOWING DOWN THE COMMERCIALIZATION OF IRRADIATION TECHNIQUES

The interplay of a number of intricate factors hinders the com m ercial­ ization in Hungary of techniques for the irradiation of foodstuffs, the unrestricted marketing of which has been approved in several countries. The introduction of large-scale industrial potato irradiation is hindered by the circumstance that potato cultivation in Hungary is declining. Yields are low and increase slowly, thus cultivation is economically not attractive and the cultivated area is decreasing steadily. The amount of potatoes 54 FARKAS

m me ¡m tm m un uns !9q j

FIG.6. Sowing area, total crop and yield per hectare of potatoes in Hungary.

consumed per annum is estimated to be about 2 million tonnes [1, 2]. The home production is only able to satisfy demand in favourable years and potatoes have to be imported in other years (Fig.6). The month to month variation in potato and onion prices in Budapest is shown in Fig.7. The drop in potato prices in April is probably due to the rapid decline of quality in the spring, while the sudden increase in June can be ascribed to the turn of season. In contrast to the 80-106Ft/t irradiation expense estimated in the previous section, some Hungarian storage experts consider 40 Ft/t (about 1% of the average retail price) to be an acceptable cost. This is probably because they do not reckon with the substantial loss accompanying spring storage and do not consider the increase in price at the very end of the se a so n . The industry processing potatoes for food purposes, an important requirement of which is the uniform quality of the raw material throughout the year, is still in an early stage and its development is actually retarded by difficulties in the raw material supply. Potatoes used for industrial pro­ cessing have to be stored at higher temperatures in order to retain their COMMERCIALIZATION IN HUNGARY 55

FIG.7. Price of potatoes in Budapest, 1972-73.

sugar content at a lower level, or reduce it, thus sprout inhibition is particu­ larly important. The fact that the use of chemical sprout inhibitors is also very low in Hungary may be explained by the lack of a potato-processing industry necessitating sprout inhibition. The projected amount of potatoes used in the next few years for the manufacture of food products is not expected to exceed 50-60 thousand tonnes [39], amounting to about 2.5-3% of the national consumption. The insufficient cultivation is in the majority of cases accompanied by out-of-date, primitive conditions of storage, presenting one more obstacle in the way of introducing irradiation. Even in 1971 stopgap arrangements were applied to store more than two-thirds of the potatoes destined for winter storage [40]. At the same time storage is rather decentralized and broken up into small quantities. Storage in clamps limits the period of irradiation inhibition of sprouting to the few weeks immediately following harvesting. This would permit of a very poor utilization of the equipment constructed to treat potatoes and irradiation immediately after harvesting rather than after letting them rest for some time entails the danger of microbial spoilage of the treated p ota toes. The construction of up-to-date storage facilities is an essential con­ dition of the application of irradiation to inhibit sprouting. In the long-range storage development project only the modernization of bulk storage is con­ sidered, while in view of radiation treatment storage in large cases seems to be most favourable. The advantage of this type of storage lies in the possibility of harvesting the potatoes in the field in these cases and using them for transport, irradiation and storage. Thus damage due to handling and storage would be reduced, which is very important in the case of radiation treatment. Storage in cases prevents the spreading of spoilage, permits the control of stored potatoes and provides constant accessibility. 56 FARKAS

хЮ

ISO -

' WO -

1 a 80 1 >3 I Í0 - 1 ! 1 I I i . I m e- wet- wes 1967 W6S weg W70 -1960 -1965

FIG. 8. Onion crop in Hungary [18].

Storage in large cases has not been considered; however, it has not yet been the subject of a detailed economic study in Hungary. Data on onion cultivation are shown in Fig.8. One third of the annual produce of about 120 thousand tonnes is exported, the other third being processed by the food industry (for canning and dehydration) and only the remainder is marketed for home consumption. In this case, too, difficulties arise from the limited period of radiation treatment, if the treatment of onions cannot be combined with the treatment of other produce. Another problem would also be raised by the treatment of onions, which is valid for mushrooms as well, these two products being important export items. Their irradiation could be only realized in concert with foreign partners. So far the irradiation of mushrooms has been approved only by the health authorities of another exporting country, the Netherlands. The advantages of the irradiation of mushrooms, the retardation of ageing, could only be utilized with m ore up-to-date packaging. The weight loss, which becomes quite substantial after some time with the open cases used at present, could be slowed down by a better method of packaging. The construction of radiation sources should be taken into account in the national storage development project; however, this would require a more advanced status of approval by the health authorities and more encouraging export prospects. The introduction of methods reducing storage losses is frequently hindered by a psychological-econom ic factor, namely the storehouse and trade employees take the 'allowed' part of losses for granted and inevitable and are not interested in an extensive reduction of losses — even though this is of great national importance.

5. FUTURE TASKS

To realize the technical and economic advantages inherent in irradiation techniques a great deal of co-ordinated development work is required both in Hungary and abroad. COMMERCIALIZATION IN HUNGARY 57

The modernization of storage and packaging techniques is a precondition for realization in Hungary. The establishment of radiation sources has to be taken into account, far m ore seriously than so far, in the co-operative storage development programme. However, development in this field in Hungary is dependent on the international status of food irradiation. This technique can only occupy its due place in the world and in a sm all country like Hungary if the international attitude to public health clearance undergoes a profound change. The basic conditions are that the food-irradiation technique is considered a physical method of preservation and obtains the approval of the health authorities. Legislation that prohibits food irradiation in general and grants permission only for the treatment of certain products necessitates endless wholesomeness testing of individual foodstuffs and this hinders not only the establishment of irradiation plants, but puts a check on com mercial experiments as well. Economic estimates clearly show that the plant-utilization problems arising from the seasonal character can only be overcome if a suitable variety of processable raw materials are available. In view of the above the importance of international collaboration on the health and legal aspects of irradiation cannot be sufficiently stressed. The International Food Irradiation Project, as laid down in Karlsruhe, promises a measure of success; however, the redoubled support of individual govern­ ments and of the specialized UN agencies and in particular WHO seems extremely desirable.

REFERENCES

[1] KSH Mezógazdasági Adattár (Collection of Agricultural Data) Current Statistical Communications,

Central Office of Statistics, Budapest (1967-70). [2] SÂRVÂRI, I ., A burgonyanemesités és termesztés komplex kutatása (Complex research of the breeding

and cultivation of potatoes), Országos Kutatási Program, Keszthely, 1970. [3] PARÂDI, E ., A burgonya csirázásgátlása besugárzással (Irradiation of potatoes to inhibit sprouting), Atomtech.Tájékoztató 1_ (1964) 800-6. [4] HORVÂTH, L., VARSANYI, I., TOLNAI, L.. Kisérletek a burgonya tárolási veszteségének csókkentésére (Experiments into the reduction of potato storage losses) unpublished, 1965. [5] SIMON, J., BECZÂSSY, K ., A burgonya tárolhatóságának és ipari feldolgozásának fokozása ionizáló sugárzások alkalmazásával (Application of ionizing radiations to improve storage stability and suitability

to processing of potatoes), Res.Rep.Kozponti Elelmiszeripari Kutató Intézet, Budapest (1968). [6] SÂRVÂRI, I., SIMON, J., NAGY, Z ., BECZASSY, K ., A burgonya tárolhatóságának és ipari feldolgohatóságának fokozása ionizáló sugárzások alkalmazásával (Application of ionizing radiations to improve the storage stability and suitability to processing of potatoes). Res. Rep. Keszthelyi Agrártudo-

mányi Egyetem Burgonyanemesitési és Viruskutatási Csoportja, Keszthely és a Kozponti Élelmiszeripari

Kutató Intézet, Budapest (1969). [7] HENDEL, C .E ., BURR, H .K ., Treatments of potatoes with gamma rays: Effects of delay between harvest

and irradiation. Food Technol. 15^ (1961) 218-19.

[8] KISS, I., FARKAS, J., unpublished data. [9] BURTON, W ., HANNAN, R .S., Use of gamma radiation for preventing the sprouting of potatoes, J.Sci.

Food Agrie. 8 (1957) 705-15. [10] HERRMANN, jT, RATHS, J., Stoffwechselverà'nderungen in Kartoffeln nach Behandlung mit ionisierenden

Strahlen, Nahrung 2 (1959) 1062-90.

[11] SCHWIMMER, S., "b u r r , H .K ., HARRINGTON. W .O ., WESTON, W .J., Gamma irradiation of potatoes.

Effects on sugar content, chip colour, germination, greening and susceptibility to mould, Am .Potato J.

34 (1957) 31-41.

[12] LINDNER, K ., SZOTYORI, K ., Ionizáló sugárzással csirázásgátolt burgonya szolaninképzése. II,

(Solanine formation in irradiated potatoes. Part II), Elelm iszerv.Kozl. 17 (1971) 25-29. 5 8 FARKAS

[13] SZ0TY0R1, К ., LINDNER, К ., A burgonyában sugárkezelés hatására végbemenô egyes egészségiigyi jelentoségü biokémiai változások vizsgálata (Study of biochem ical changes of nutritional importance

occurring in potatoes upon irradiation). Res.Rep. Institute for Nutrition, Budapest (1971).

[14] FORSTER, H ., "Burgonyafajták és fajtajelôltek termôképességének vizsgálata" (Investigation into the

yields of new breeds of potatoes) in: 1971 évi Országos Fajtakisérletek, Országos MezÓgazdasági Fajtakisérleti Intézet, Budapest (1973).

[15] BECZNER, J., unpublished data.

[16] SPARROW, A .H ., CHRISTENSEN, E ., Improved storage quality of potato tubers after exposure to 60Co gammas, Nucleonics 12 8 (1954).

[17] LÉVAVÁRY, B ., Vôrôshagyma tárolás alatti kihajtásának gátlása (Inhibition of sprouting during the

storage of onions), Co-operative Bureau for Store Development and Technology, Budapest (1967).

[18] FARKAS, J., Gamma-s'ugárzás hatása a gyôkérzôldségek és a hàgyma tárolási veszteségeire (Effect of gamma radiation on the storage losses of root-crops and of onions), unpublished Res.Rep., 1971.

[19] KÀLMÂN, B., unpublished data. [20] MULLINS, W .R ., BURR, H .K ., Treatment of Onions with gamma rays. Effects of delay between harvest

and irradiation, Food Technol. 15 (1971) 178.

[21] KISS, I., BALAZS-SPRINCZ, V ., FARKAS, J., Üzemi célubesugárzó berendezés zoldség és gyümôlcs

tartósitás céljára (Industrial irradiation plant for the preservation of fruit and vegetables), Review of related literature, Central Food Research Institute, Budapest, 1970.

[22] ST ADEN, O .L ., "Radiation preservation of fresh mushrooms", Mushroom Science (Proc. Symp.

Wageningen, 1965; Proc.Cong.Amsterdam, 1965) £, Centre for Agricultural Publications and Documentation, Wageningen (1965) 457-61.

[23] MACQUEEN, K .F ., e ta l., Gamma irradiation, irradiation of Canadian grown fruits and vegetables using a mobile cobalt-60 irradiator, c .2 .1 6 ., Proc. 2nd Int.Cong.Food Science and Technology, Warsaw,

(1966) c. 2.16, Abstracts of papers, pp. 237-38.

[24] KOVACS, E., VAS, К ., FARKAS, J.. Ionizáló sugárzások alkalmazása a friss csiperkegomba eltartható-

ságának novelésére (Increasing the storage life of cultivated mushrooms by ionizing radiations), Kutatási

beszámoló, Kozponti Élelmiszeripari Kutató Intézet, Budapest (1968).

[25] KOVACS, E., VAS, К ., FARKAS, J., A termesztett csiperkegomba eltarthatósági idejének novelése

ionizáló sugárzással (Increasing the storage life of cultivated mushrooms by ionizing radiations), Atomtech.Tájékoztató 7 (1968) 349-54.

[26] KOVACS, E., VAS, К ., Ionizáló sugárzások alkalmazása a friss csiperkegomba eltarthatóságának

novelésére (Increasing the storage life of mushrooms (Agaricus bisporus) by ionizing radiations), Res.Rep. Central Food Research Institute, Budapest (1969).

[27] KOVACS, E., VAS, К ., Effect of ionizing radiations on some organoleptic characteristics of edible mushroom, Acta Aliment. Acad.Sci.Hung. 3 (1974) 11-17. .

[28] KOVÁCS, E., VAS, К ., Effect of ionizing radiation on post-harvest ripening processes of cultured mushrooms (Agaricus bisporus), with special reference to the rates of respiration and of ethylene production, Acta Aliment.Acad.Sci.Hung. £(1974) 19-25.

[29] SÁRVARI, I., NAGY, Zs., Jelentés a radiologiai eljárással tartósitott és kezeletlen burgonyaminták

konyhatechnológiai és érzékszervi birálatáról (Report on the cooking technological and sensory evaluation of irradiated and untreated potato samples), Keszthelyi Agrártudományi Egyetem Burgonyanemesitési és Viruskutatási Csoportja, Keszthely, unpublished. * [30] FARKAS, J., BARNA, J., Az ionizáló sugárzásos tartósitási módszer bevezetése létjogosultságának

vizsgálata, külônos tekintettel a burgonya besugárzásos kihajtásgátlására (A study into the com m ercial­

ization of food preservation by ionizing radiation, with particular reference to potato irradiation) Elelmez. Ipar 26 (1972) 33-41.

[31] SIMON, J., KIRALY, Z ., BALAZS, V ., Tanulmányterv a burgonya ionizáló sugárzásos nagyüzemi

tárolásának megoldásához szükséges besugárzó rendszer ktalakitásához (Research project of an irradiation plant for promoting large scale potato storage), Kozponti Elelmiszeripari Kutató Intézet, Budapest (1970).

[32] FARKAS, J., BALÁZS-SPRINCZ, V ., ZUKÁL, E., A burgonya és vôrôshagyma ionizáló sugárzásos

kihajtásgátlása hazai alkalmazása várható gazdasági kihatásainak és az e célra szolgáló sugárállomások

lehetséges tipusainak osszehasonlitó müszaki gazdasági elemzése (Comparative technical econom ical analysis of the economic effects to be expected of inhibition by ionizing radiations of sprouting in

potatoes and onions and the possible types of irradiation equipments serving this purpose) Res.Project, Central Food Research Institute* Budapest, 1971. [33] BALÁZSNé, SPRINCZ, V . A sugárzásos élelmiszeitartósitás gazdaságosságának elemzése (Rentability studies on radiation preservation), Elelmiszertudomány 3 (1969) 3-11.

[34] ANON., The Commercial Prospects for Selected Irradiated Foods, US Department of Commerce, Business and Defense Administration, Washington, D .C . (1968). COMMERCIALIZATION IN HUNGARY 59

[35] KUKACKA, L.E ., MANOWITZ, B., Estimating gamma-radiation processing cost. Nucleonics 23 1

(1965) 74-?8 v [36] MACQUEEN, F .K ., "Some considerations which influence the economic feasibility of food irradiation".

Factors Influencing the Economical Application of Food Irradiation (Proc.Panel Vienna, 1971), IAEA,

Vienna (1973) 1. [37] URBAIN, W .M ., "Food irradiation: benefits and limitations", Factors Influencing the Economical Application of Food Irradiation (Proc.Panel, Vienna, 1971), IAEA, Vienna (1973) 101-17.

[38] DEL VAL COB, М ., DE LA CRUZ CASTILLO, F., "The effect of technological parameters on the

economic design of food-irradiation units", Factors Influencing the Economical Application of Food

Irradiation (Proc.Panel Vienna, 1971), IAEA, Vienna (1973) 37.

[39] LORINCZ, J., Tájékoztató jelentés a konyhai munkât megkônnyito kész es félkész burgonyatermékek ipari elóállitásának helyzetérôl és a fejlesztés tovâbbi lehetôségeirôl (Informatory report on the industrial

production of ready-to-cook and ready-to-eat potato products and the possibility of their further

development), MEM Term elés- és Míiszaki Fejlesztési Foosztály, Budapest (1971). [40] BANKE, A ., A mezogazdasági és élelmiszeripari termékek tárolási helyzete hazánkban (Storage of

agricultural produce and food industrial products in Hungary) Raktárgazdálkodás 9 1 (1971) 1 7-2 2 .

PETITIONS AND CLEARANCES FOR IRRADIATED FOOD ITEMS: IMPLEMENTATION OF LEGISLATIVE REQUIREMENTS IN MARKETING TESTS

E. EISENBERG, E. FOA, M . LAPIDOT, R. PADOVA, K . ROSENBERG, I. ROSS . Soreq Nuclear Research Centre, Yavne, Israel

Abstract

PETITIONS AND CLEARANCES FOR IRRADIATED FOOD ITEMS - IMPLEMENTATION OF LEGISLATIVE REQUIREMENTS IN MARKETING TESTS.

Formulation of legislative requirements regarding irradiated food items and their implementation are

basic steps in a com mercialization campaign of such products. The petitions for clearance of irradiated vegetables in Israel are discussed in the light of the attitude of the Ministry of Health to the matter and the

corresponding procedures adopted in the formulation of the petitions. The regulations issued by the Ministry

on food items preserved by irradiation are reviewed, as are the clearances of irradiated potatoes and onions.

The legislative requirements regarding actual irradiation and storage for marketing of the products and the means and procedures adopted to im plem ent these requirements in a series of test marketing periods are presented. Some conclusions are formulated to guide planners of irradiated-food commercialization campaigns.

1. PETITIONS AND CLEARANCES

1.1. Introduction

Petitioning the relevant health authorities for clearance of model products (most likely to benefit economically and technologically from an irradiation process and most likely to demonstrate the acceptability and feasibility of irradiation processes on a com m ercial scale) and obtaining the1 corresponding approvals is one of the criteria considered essential for the systematic implementation of a commercialization campaign for irradiated products [1]. The need for appropriate legislation on irradiated potatoes and onions (chosen locally as model products) at an early stage of the commercialization campaign has, therefore, been'recognized as an important element of the local food irradiation programme [2]. The experience obtained in Israel regarding procedures of petitioning and granting approvals should be instructive in related situations in other countries that desire to com m ercialize irradiated food items and it is, therefore, related below.

1.2. Attitude of the Ministry of Health

The local approach to action furthering irradiated food legislation was based on; (a) The absence of legislation on the marketing of irradiated food for human consumption

61 62 EISENBERG et al.

(b) The acceptance, by the Ministry of Health, of wholesomeness data and clearances from other countries (particularly the USA) as a basis for local approval of food additives. The preliminary discussions with officials of the Israel Ministry of Health regarding possible local legislation on irradiated food were aimed at acquainting the Ministry with the matter and the SNRC with the procedures adopted by the Ministry in related cases. The Ministry of Health then consulted with the special committee on food clearances, presenting before it a résumé of the current status of clearance of irradiated foods in other countries. The easiest and quickest procedure for obtaining suitable legislation in Israel was to treat irradiation not as a process but rather as analogous to a food additive (an attitude somewhat similar to that adopted by the FDA in the United States of America). In the case of a new process new legislation would have been required, involving several years of parliamentary legislative work. The approach adopted allowed the inclusion of irradiated food in regulations within the existing Public Health (Rules as to Food) Ordinance from 1935, which can be amended by the Director General of the Ministry of Health by exercising the powers vested in him under section 3 of the Ordinance. The Ministry of Health agreed to accept a petition for the clearance of irradiated potatoes for human consumption, which was to include a series of essential items of information [3] , provided two additional prerequisites were met: (a) That a need for the treatment under local conditions and its technological effectiveness could be shown (b) That the treatment was economically feasible and a suitable com ­ m ercial customer was interested in the application of the method. These seemingly irrelevant prerequisites are based on an internationally accepted principle [4]. Both were demonstrated satisfactorily for potatoes and onions by data incorporated in the economic feasibility report [5, 6] and by a series of lab-scale experiments [7-17] proceeding in parallel [18]. Another suggestion of the Israeli Ministry of Health was the presentation of documentation on the existence of clearances on the particular food in at least one, preferably two, countries.

1.3. The petition for sprout prevention in potatoes by use of gamma irradiation

The petition [19] for preventing sprouting of potatoes to be used for human consumption by means of gamma irradiation was submitted on 24 February 1966 and was accompanied by á letter that stressed both the two prerequisites mentioned above and the existence of clearances in Canada, USA and USSR. The petition contained the following data requested by the Ministry of Health: type of food to be irradiated, purpose of irradiation, type of radiation source, description of radiation process, packaging materials, dose, and method for determining the dose absorbed by food, together with additional data including: general principles of ionizing radiation and its interaction with matter, influence of gamma radiation on potatoes, wholesomeness aspects and extensive literature references. Also included were all relevant material available on wholesomeness of irradiated foods and the chapters on wholesomeness in petitions from Canada, USA and USSR, giving both the petitions and the text of the clearances by these three countries. LEGAL ASPECTS IN ISRAEL 63

1.4. Issuing regulations on food preservation by irradiation

The Ministry decided that it would consider food irradiation as a process that is forbidden. However, special regulations were formulated to indicate that this is positive legislation with provisos for exemptions. These regulations [20] , cited as Public Health (Preservation of Foodstuffs by Radiation) Regulations, com prise (in addition to definitions) paragraphs entitled "Foodstuffs permitted to be preserved by radiation", "Import of irradiated foodstuffs" and "Marking of irradiated food". These regulations are sufficiently general to allow clearance of many i foodstuffs, provided the petitioner presents the required wholesomeness, technological and economic data. In each particular case, however, the Director General of the Ministry of Health will determine the foodstuff, the type of irradiation and the maximum permissible dose. These will be published as clearances in special schedules. In addition, a written permit must be obtained from the Director General containing detailed conditions on the irradiation process, including the control measures that ensure that the maximum dose is not exceeded in any individual piece of food. The labelling requirement "Foodstuff Preserved by Radiation" was considered rather harsh, mainly because the word "preserved" is generally associated in the mind of the consumer with "unfreshness" and the word "radiation" has many implications. However, considerable foresight was shown by applying the same requirements to locally produced or imported irradiated food, thus establishing criteria for future programmes of import or export of irradiated food. The Ministry of Health, in consultation with a special advisor on carcinogenic aspects of food toxicology, examined the material appended. The final clearance was granted by the Ministry of Health on 5 July 1967, 16 months after the date of submission.

1.5. Clearance of irradiated potatoes as first exemption

The negative aspects of the regulations (the general prohibition, the sentence on the label) were overshadowed to a considerable extent by the fact that the Ministry of Health withheld issuing the regulations until the first clearance (as an exemption) could be issued simultaneously. Indeed, contrary to the issuing of the UK regulations published at about the same time, the local regulations were considered everywhere as a clearance and not as a general prohibition of irradiated food. The schedule, published on 5 July 1967 [20] as a supplement to the regulations, cleared potatoes irradiated with cobalt-60 gamma rays up to a maximum dose of 15 000 rads. )■ 1.6. The petition for sprout prevention in onions by gamma irradiation

The petition [19] for preventing sprouting of onions to be used for human consumption by means of gamma irradiation was accompanied by a letter that stressed the two prerequisites mentioned in section 1.2, noting also the existence of clearances in Canada and USSR. It was submitted on 13 April 1967 (i.e. before the regulations mentioned in section 1.4 had been issued publicly). This petition contained only specific information on the justification and need for the irradiation process in the case of sprout prevention in onions, on the influence of gamma radiation on the onion 64 EISENBERG et al. components and quality, and on the corresponding wholesomeness aspects. Appended to the petition were the Canadian petition, the Israeli petition for clearance of irradiated potatoes and wholesomeness data published in Canada. Because of the more advanced status of onion-irradiation technology in Israel (compared to that of potato-irradiation technology in 1966), the petition contained information on the benefits of irradiation accruing to local onion varieties.

1.7. Clearance of irradiated onions

After considerable scrutiny of the evidence, the schedule of the Public Health (Preservation of Foodstuffs by Radiation) Regulations 5727-1967 was changed to cover clearance of onions irradiated with cobalt-60 gamma rays up to a maximum of 10 000 rads [21]. This was published in the Israel Official Gazette after approval on 14 July 1968, just in time for the irradiation of the onions in the first marketing and consumer-acceptance test series [22].

1.8. Petitions for clearance of other foods and feeds

The open-minded attitude of the Ministry of Health to food irradiation has been accompanied by a reciprocal attitude on the part of the Israel AEC. Any new information available to the AEC is transmitted immediately to the Ministry of Health and vice versa. In addition, new petitions are discussed informally before submission in order to clear any controversial points beforehand. As a result of the publication of the FAO/IAEA/WHO Committee recom ­ mendations regarding clearance of irradiated wheat and wheat products a petition was submitted by the AEC in October 1970 [23]. There was, however, no action because of the absence — at the time — of a public or com m ercial group ready to guarantee application of the process on a commercial scale. The Ministry of Health promised speedy treatment of the petition as soon as negotiations with local packers and distributors of wheat products are completed to assure the Ministry of marketing and consumer-acceptance tests. The Ministry of Health also considered what approach it should take toward irradiated farm animal feed. Feed is not normally dealt with under the Public Health (Rules as to Food) Ordinance and Regulations of the Ministry of Health, but under Ministry of Agriculture Regulations. Since, however, the meat of farm animals raised on irradiated feed is to be consumed by humans, and is thus included in the definition of food1, the Ministry finally decided to accept a petition. The AEC accepted this decision on the grounds that feed clearance by Ministry of Health Regulations would assist in inducing customer acceptance. A petition to clear irradiated poultry feed [24] was hence submitted in October 1972, based on the Canadian petition and clearance [25, 26] and clearance has been obtained in July 1973 [27].

1 "Any article which ordinarily enters into or is used in the composition or preparation of human food ..." [28]. LEGAL ASPECTS IN ISRAEL 65

2. IMPLEMENTATION OF LEGISLATIVE REQUIREMENTS IN MARKETING TESTS

2.1. Legislative requirements

2.1.1. Marketing of irradiated products

A food irradiated for preservation can be marketed, provided the following requirements are met: (a) It is a food considered in the schedule of Regulations and has been irradiated, in accordance with'this schedule (b) It is packed and clearly marked with special label containing the phrase "Foodstuff Preserved by Radiation". The latter requirement is a handicap because the irradiated product cannot be sold in bulk (as customary at the time) and because the word "preserved" implies that the product is not fresh. However, the latter has been overcome in the marketing tests by careful publicity [29].

2.1.2. Irradiation and storage

The aim of these requirements permits [30, 31] is to make sure that the products are irradiated according to the schedule, that they are easily identified, and that their irradiation history is confirmed by written or printed records. These requirements can be summarized as follows: (a) The irradiation must be effected in an approved irradiation facility, which is capable of performing the type of irradiation required by the schedule without exceeding the maximum permissible dose, i. e. ensure the reproducibility of the dose in each individual batch. (b) This latter capability must be easily demonstrable and checkable by dosimetric means. (c) The dose absorbed in each sampling must be measured by a standard and accepted procedure of known reproducibility and error. (d) The dosimetric results must be recorded individually in a special hard cover ledger. (e) The irradiation process parameters must be recorded both by an automatic recorder and in a hard cover logbook. (f) • The irradiation must be performed under the supervision of approved chief operators or engineers. (g) Each batch must be numbered and easily identifiable throughout the irradiation and storage process. (h) The process must be checked frequently by Ministry of Health inspectors. (i) Records must be kept for 7 years. (j) Any product found to be unsaleable according to the above require­ ments must be destroyed.

2.2. Implementation of requirements in marketing tests

2.2.1. Control of irradiation process and identification of product batch

In the lab-scale test series the potatoes were packed in commercial sacks and the onions in commercial boxes [32]. They were irradiated batch- wise in the irradiator of the SNRC reactor pool [33] . The irradiation 66 EISENBERG et al.

process was controlled by timing the irradiation (after performing dosimetric measurements on actual batches of 30Ü-400 kg each) using a stopwatch and this time was recorded automatically on a Rustrack recorder. Various means to ensure prevention of underexposure and overexposure have been described elsewhere [32] , as have the dosimetric procedures adopted. The individual batches were identified by suitable tags, which allowed rejection — at a later time — of batches that had not received the proper dose (as established by dosimetric means and by reference to the irradiation process logbook). In the bench-scale test series the potatoes and the onions were irradiated in 20 kg boxes in a continuous motion irradiator [32] . Before and after irradiation the potatoes were placed in 400 kg pallet boxes, which were tagged to correspond to a particular group of about 20 irradiation boxes. Onions were left in the commercial boxes. The irradiation process (after clearance of the irradiation facility by the Ministry of Health) was controlled by electrical and mechanical means, which determined the duration of passage through the irradiation field [32] , and was also recorded using an automatic timer, a recorder and a logbook. Dosimetric procedures differed in certain aspects from those used in the batch process [32]. The product batch was identified by numbered tags that corresponded to groups of 10-20 irradiation b o x e s.

2.2.2. Report of dosimetry and process control data to the Ministry of Health and obtaining of marketing permit

The data obtained in preliminary dosimetric mapping experiments, together with relevant geometric and time data, were reported to the Ministry of Health. These reports were followed by a detailed report containing all dosimetric readings of the dosimeters attached to individual boxes. In the accompanying letter the batch numbers .were indicated and the reason for overdose suggested (these batches were destroyed). These reports, the logbooks and recorder strips were checked by the Ministry of Health inspectors, who sent letters of verification to the Ministry. Subsequently the final marketing permit was issued [32] ¿ The products were repacked in 1 or 2 kg bags and each was tagged with the label containing the phrase "Foodstuff Preserved by Irradiation".

2.3. Discussion and conclusions

A cursory examination of the complex data-collecting and reporting schemes, devised in conjunction with the Israel Ministry of Health, indicates that control of food irradiation processing involves a complicated set of procedures. However, once the initial 'pathfinding' troubles have been settled and a model of data-collecting and reporting has been established, it can easily be adapted on a commercial scale where the control is more sophisticated, thereby eliminating the drudgery of logbook recording. Dosimetry will remain the main and only positive proof accepted by Health Authorities that the permissible dose has not been exceeded, but the larger containers useable in com m ercial plants will facilitate application of the complex control schemes. Evolution of a simpler dosimeter, i. e. a rigid one, for the dose range used in vegetable irradiation will be a very significant boon for commercial food irradiation processes in many countries. LEGAL ASPECTS IN ISRAEL 67

Although accumulation of experience with com m ercial food irradiation facilities will lead to gradual mitigation of the present rigid Ministry of Health requirements, particularly with regard to identification and labelling which make bulk processing difficult, the present restrictions do not prevent the development of food irradiation processes. The system evolved by the Israel Ministry of Health has shown complete confidence in the officials when confronting vociferous prejudiced minorities, who have tried by means of letters to the press and direct appeals to oppose the introduction of food irradiation into Israel. All these attempts have been completely refuted by the Ministry of Health.

REFERENCES

[1] LAPIDOT, М ., BEERI-KATZNELSON, У ., SHIELD, O ., SOS/TO 3rd Int. Cong., Washington, 1970;

Int. J. Radiat. Eng. 3 (1973).

[2] LAPIDOT, M ., Factors Influencing the Economical Application of Food Irradiation (Proc. Panel Vienna,

1971), IAEA, Vienna (1973) 65-74. [3] FOA, E ., EISENBERG, E ., LAPIDOT, М ., KAHAN, R .S., Food Irradiation (Proc. Symp. Karlsruhe,

1966), IAEA, Vienna (1966) 891-8; FOA, E ., EISENBERG, E ., Legal Problems in Food Irradiation,

IAEC Spec. Rep. (1967). [4] WORLD HEALTH ORGANIZATION, Technical Report Series No. 129 (1957) 13.

[5] COHEN, Y ., Economic Feasibility of Using Large Radiation Sources for the Preservation of Potatoes and Onions, National Council.for Research and Development, Israel, Israel AEC Spec. Rep. (1967).

[6] COHEN, Y ., LAPIDOT, М ., PUDER, М ., Campaign for the Commercialization of Irradiated Vegetables II. Economic Feasibility of Potato and Onion Irradiation in Israel, unpublished manuscript,

1 9 7 2 . [7] KAHAN, R .S., TEMKIN GORODEISKI, N ., EISENBERG, E ., Rep. IA-1082 (1965) 272-73.

[8] KAHAN, R .S., TEMKIN GORODEISKI, N .. Rep. IA-1128 (1966) 168-70.

[9] KAHAN, R .S ., TEMKIN GORODEISKI, N ., "Storage tests and sprouting control on up-to-date variety

potatoes and on an experimental onion variety (Beit Alpha)", Preservation of Fruit and Vegetables

by Radiation (Proc. Panel Vienna, 1966), IAEA, Vienna (1968) 29-38. [10] KAHAN, R .S., TEMKIN GORODEISKI, N ., PADOVA, R ., AVIDOV, М ., Rep. IA-1128 (1966) 171.

[11] KAHAN, R .S., TEMKIN GORODEISKI, N ., PADOVA, R. , Rep. IA-1168 (1967) 148-49.

[12] TEMKIN GORODEISKI, N ., KAHAN, R .S., Proc. Symp. Potatoes, Beit Dagan, 1966-67, Min. Agrie.

Extension Services (1967) (in Hebrew). [13] KAHAN, R.S., PADOVA, R. , Rep. IA-1190 (1968) 219. [14] KAHAN, R .S., TEMKIN GORODEISKI, N ., PADOVA, R ., Rep. IA-1168 (1967) 149-50.

[15] KAHAN, R .S., TEMKIN GORODEISKI, N ., PADOVA, R ., Rep. IA-1190 (1968) 222.

[16] KAHAN, R .S., PADOVA, R ., Rep. IA-1190 (1968) 223. [17] PADOVA, R. , ROSS, I., KAHAN, R .S., Rep. IA-1218 (1969) 179-80. [18] LAPIDOT, M ., Proc. Peaceful Uses of Atomic Energy (Proc. Conf. Geneva, 1971) _12, UN, New York,

IAEA, Vienna (1972) 279-98. [19] FOA, E ., EISENBERG, E ., Petition to Ministry of Health, 13.4.1967, Israel Atomic Energy Commission,

Y a v n e . [20] "Regulations concerning the preservation of foodstuffs by radiation", 5727-1967, Public Health (Rules

as to Food) Ordinance, 1935, Ministry of Health Food Additives Legislation, Jerusalem (1970)

(English version) 4 0-41. [21] BARZILAI, I ., BRACHOT, D ., G ovt.1 Israel Regulations Bull. 2259 (25 July 1968) 1968 (in Hebrew);

Eng. Transi.; Min. Health Food Additives Legislation, Jerusalem (1970) 40-41.

[22] LAPIDOT, М ., PADOVA, R ., ROSENBERG, C ., ROSS, I., Semi-commercial Test of Onion Irradiation

Storage and Marketing 1968/69, Israel AEC Internal Rep. (in Hebrew).

[23] EISENBERG, E., LAPIDOT, М., Petition to Ministry of Health, Oct. 1970. [24] EISENBERG, E., LAPIDOT, М., Petition to Ministry of Health, Oct. 1972.

[25] Process for the elimination of salmonella from animal feeds by gamma radiation, jointly prepared by

Bio-Research Laboratories Ltd. and Com mercial Products Atomic Energy of Canada L td., Ottawa,

Canada (1971) Vol. I, III, IV, V . 68 EISENBERG et al.

[26] Letter of approval written by C .L . Stevenson, Chief, Feed and Fertilizer Section Plant Products

D iv is io n . [27] Ministry of Health Food Additives Legislation, Jerusalem, July 1973,

[28] Public Health (Rules as to Food) Ordinance, N o.6 of 1935 (Pal. Gaz. No. 496 of 28.2.1935, Suppl.l,

p . 5 6 ) . [29] KL1NKOVITZKI, D ., Study of Irradiated Onion and Potato Marketing, Hebrew U niv., Jerusalem,

Spec. Rep. (1970).

[30] MINISTRY OF HEALTH, Permit for Irradiation of Potatoes (17 Sep. 1969).

[31] MINISTRY OF HEALTH, Permit for Irradiation of Onions (13 March 1970).

[32] LAPIDOT, М ., PADOVA, R ., ROSENBERG, C ., ROSS, I., Implementation of Irradiated Food

Legislative Requirements in Lab and Bench Scale Marketing Tests, Israel AEC Spec. Rep.

[33] LAPIDOT, М ., HARAM, S., BAB-ON, I., SATCHY, C ., KAHAN, R .S., "A versatile cobalt-60 irradiation facility within a swim m ing-pool research reactor", Food Irradiation (Proc. Symp.

Karlsruhe, 1966), IAEA, Vienna (1966) 755. IRRADIATION TREATMENT FOR SPROUT INHIBITION IN POTATOES Prospects for application in Belgium

W . SCHIETECATTE* L. N Y S** Belgian Working Group for the Irradiation o f Fruit and Vegetables (IRFEL), INACOL Institute, W ezembeek-Oppem, Belgium

Abstract

IRRADIATION TREATMENT FOR SPROUT INHIBITION IN POTATOES: PROSPECTS FOR APPLICATION

IN BELGIUM. In the present situation, taking into account both our knowledge of gamma radiation and of treatments based on Propham-Chlorpropham and our legislation and the needs of com merce, there

cannot be any question of advocating in Belgium a policy of investment aimed at the setting up of an

installation on an industrial scale. Nevertheless, there would be interest in conceiving a pilot installation, for which two modes of application would have to be compared: gamma radiation and electron accelerators.

Such a pilot installation would entail above all development work on the adequate handling and processing of treated tubers, which is basically a problem of agricultural engineering.

1. INTRODUCTION

Research on the possibilities of ionizing radiation treatment in the food sector, and in particular the use of gamma radiation from cobalt-60 sources, began in Belgium in 1958-59, primarily on the initiative of the Centre for Nuclear Studies (CEN) at Mol and thanks to the opportunities offered by this Institute [1,2]. The potato was one of the first foods considered, and an approach was made to the National Potato Research Station at Libramont, now known as the Haute Belgique Station. The latter immediately saw the need for co-ordination of the work. The subsequent collaboration gave rise to the first Belgian publication on potato irradiation [3]. As in other fields, however, the enthusiasm of the research workers was tempered rapidly by the first observations relating to undesired biochemical changes in the tuber and the difficulties in controlling them [1,4, 5]. However, the new possibilities opened up by irradiation led to the necessary planning of definite and more detailed programmes. At that time it seemed possible that by 1968-70 applications on an industrial scale could be introduced, at least as far as some foodstuffs were concerned [6]. It is against this background that a Study Group on the Irradiation of Foodstuffs [7] was set up in Belgium. The IRFEL group was formed within it and subsequently detached; it was to devote particular attention to the problems associated with the radurization of fresh vegetables and sem i-preserves, including of course potatoes.

г'г National Institute of Radioisotopes (IRE), M ol. ^ Haute Belgique Station, Libramont (State Centre for Agronomic Research, Gembloux).

69 70 SCHIETECATTE and NYS

The latter were chosen from among products on which the studies appeared to be the most advanced and with respect to which rapidly developing industrialization was apparent. In the present paper we shall describe the current status of the work and the main conclusions that emerge from it, adding some considerations of an economic and commercial nature. By way of conclusion, we shall consider the problems of applica­ tion in Belgian industry and in this connection the technological tests that would be required.

2. OUTLINE OF THE WORK

2.1. General objective of the research

The need to improve the effectiveness of treatments for inhibiting sprouting must be seen in the context of relatively lengthy preservation; both the quantitative and qualitative characteristics of the goods stored must be preserved over a long period. In Belgium the quantities stored for the purpose of marketing are tending to increase. Despite a levelling off observed in recent years, it appears that the amounts consumed per caput will be maintained (Figs 1, 2 and 3). The current expansion of the processing industries presupposes the availability of base material on a viable and stable basis for a large part of the year. The problem with respect to the period of scarcity in June and July remains; the fluctuations and excessive price increases during this period are still a disquieting economic and social factor (Fig.4). The improvement in preservation techniques is also a result of the concentration of production and markets in specific regions, the expansion of retail organizations, which is a consequence of the disappearance of cellars from modern dwellings, and increased requirements with respect to quality on the part of both industrial and private consumers. On the technological side, ordinary silos and unventilated cellars have been gradually replaced by specialized isothermal premises equipped with mechanical ventilation and, more rarely, refrigerating plant; mechanical ventilation is a means of making use of lower night-time temperátures. In the chemical field, Fusarex was followed by maleic hydrazide and other active materials, Propham (IPC) and Chlorpropham (CIPC), which came to the fore because of their remarkable effective­ ness [8]. Shortly afterwards a new physical method was introduced, namely irradiation treatment [9]. The last two techniques therefore made their appearance practically simultaneously. It should be mentioned that as the possibilities for testing and developing methods of application for these two procedures are not absolutely comparable, their introduction into current practice has of necessity not proceeded at the same rate, and this is what we have observed. When research on the treatment of tubers with gamma radiation started chemical treatments were still neither widespread nor officially authorized; hence there was further justification for seeking a method that was still better from the point of view of health and, if possible, economics. The quantitative aspect of potato preservation relates to weight loss resulting from the cumulative effect of several factors; respiration, COMMERCIAL PRODUCTION <106 1onnes> CULTIVATED AREA ( h a x I O 3) I 1. dr at ti i n Bel um. m iu lg e B in n tio a iv lt u c to ta o p nder u a e r A . 1 . FIG I 2. al oduci n Bel um. m iu lg e B in n ctio u d ro p l ia c r e m m o C . 2 . FIG S N BELGIUM IN ES O T A T O P 71 72 SCHIETECATTE and NYS

FIG, 3. Consumption of potatoes per caput.

— i------1------1------1------»------1------1— 1958 1960 1962 1964 1966 1968 1970

FIG. 4. Average annual price of potatoes in Belgium. POTATOES IN BELGIUM 73 sprouting and transpiration. These natural factors may be aggravated by accidental factors of a phytopathological nature (preservation diseases). The qualitative aspect relates to culinary characteristics and suitability for industrial processing. It should be recalled here, that physiological aging of the tuber, to which is linked its value for use, cannot be stopped but at most slowed down by lowering the temperature sufficiently. The actual sprouting is a consequence of biochemical changes and is by no means the cause of physiological aging. The anti-sprouting treatment prevents the formation of eyes but not the preceding natural biochemical changes. This explains the initial interest of research workers in the purely quantitative aspect of preservation. It should also be stressed that the .research carried out so far has neglected the development of installations specifically designed for and completely suited to potato irradiation.

2.2. Discussion of the various tests

In general terms, three types of test were carried out: (i) Tests I and II These two tests relate to the specific effects of gamma irradia­ tion and more particularly to the determination of the response of varieties as a function of the dose rate [3, 10-12]; (ii) Tests III, IV, V T h ese three tests were based on the study of irradiation treat­ ment in comparison with chemical treatment with a powder, both types of treatment having been followed by storage on an industrial scale [13 - 19]; (iii) Test VI The objective of this test was to determine methods of applying a chemical treatment based on IPC/CIPC: powder treatment, aerosol treatment and fumigation.

The observations relate to weight loss, effectiveness of inhibition of sprouting and amount of residues present at the time of household and industrial use [20]. This test, which is of some interest in its own right, loses none of its value in the context of a comparative study with irradiation. The data regarding the various irradiation tests and the associated determinations are summarized in Tables I, II and III. The general conditions and the variable parameters are shown in Table IV. Three other factors are commented on below:

Time of treatment: The time chosen can be considered to be equi­ valent in the various tests. Depending on the maturity of the variety, it ranges from the beginning of September to the beginning of December, but is in any case after induration of the skin. Storage conditions (except for the storage temperatures, listed in Table IV): The remaining conditions may be considered comparable and of less relative importance. However, this does not apply to the industrial storage test (No.V), in which the relative humidity was found to be very variable. Variety: This factor was dealt with only in Test N o.l, in a compara­ tive study of nine Belgian and foreign varieties, viz. Bintje, Climax, Doré, Eersteling, Electre, Gari, Gaumaise, Pimpernel and Saskia. 74 SCHIETECATTE and NYS

TABLE I. SUMMARY OF THE FACTORS STUDIED AND THE DETERMINATIONS MADE IN THE VARIOUS TESTS: QUANTITATIVE ASPECT

T e s t N o . Factor and determination made I 11 Ill IV V

Comparison with untreated batch X X X X X

C o m p a riso n with batch treated with IPC /Q P C - - X X X

Comparison with industrial preservation - - X - X

1. Weight ] loss

1 . 1 . Sprouting

Visual comparison (reversibility) X X X X X

Decrease in losses {°jo) X X X X X

Eyes (

1 . 2 . Respiration

Total sugars X X X X

Amount of reducing sugars - X - X X

Oxygen absorption X - - - '

1 . 3 . Transpiration

Water losses X - - X X

1 . 4 . D isea ses

Necrosis of phytopathological origin X X Percentage of decay - - X X X

2. Chemical changes

2.1. Reducing power

Glutathione X

2 . 2 . M e ta b o lis m

Nucleic acid X - - - _

2 . 3 . Composition

Starch X X X

Total protein X - - X X

Insoluble protein - - - X X

C e llu lo s e X - - X X

Ether extracts - - - X X

Ash X - - X X

(X = test carried out) Ю ТА TOES IN BELGIUM 75

TABLE' II. SUMMARY OF THE FACTORS STUDIED AND DETERMINATIONS MADE IN THE VARIOUS TESTS: QUALITATIVE ASPECT

T e s t N o .

Factor and determination made I II Ill IV V

Comparison with untreated batch X X X X X

Comparison with batch treated with IPC/CIPC - - X X X

Comparison with industrial preservation - - X , - X

3. Culinary assessment

(1) Characteristics of assessment

Behaviour on cooking X - X X X

Consistency of the flesh X - X X X

Floury appearance X - X X X

H u m id ity X - X X X

Granulation - - X X X

(2) Characteristics outside assessment

C o lo u r X X X X X

Blackening after cooking X X X X X

Appearance when served - - X X X

T a s te - - X X X

(X = test carried out)

The Bintje was selected for all other tests in view of its agronomic importance. We present below observations and preliminary conclusions with respect to these tests.

2.2.1. Test No.1

Quantitative and chemical aspect

A dose/variety interaction was noted with respect to the following fa c t o r s :

Sprouting inhibition threshold Increase in the glutathione content Decrease in nucleic acid content Reduction in rate of oxygen consumption Reduction in starch content, accompanied by an appreciable increase in content of sugars.

Qualitative aspect

Irradiation in no way altered the manner in which the variety can be used and its culinary quality as such. 76 SCHIETECATTE and NYS

TABLE III. SUMMARY OF THE FACTORS STUDIED AND DETERMINATIONS MADE IN THE VARIOUS TESTS: APTITUDE FOR INDUSTRIAL TRANSFORMATION

T e s t N o . Factor and determination made I II Ill IV V

Comparison with untreated batch X X X X X

Comparison with batch treated with 1PC/C3PC - - X , X X

Comparison with industrial preservation - - X - X

1. Industrial pretreatment

Losses on peeling - - X - -

Appearance on peeling - - X - - Losses on trimming - - - - X

D e n sity - - X - -

2. Precooked chips

C o lo u r - - X X X

Purity of colour - - - X X

General appearance - - - X X B la c k en in g - - - X X Water (dry matter) - - - - X

Fat content - “ - - X

3. Cooked chips

Duration of cooking - - - X X

Colour (browning) - - X X X

B la c k en in g - - - X -

4 , Crisps

Weight loss - - - X X

Colour (browning) - - X X X

Industrial yield - - X X X H u m id ity - - - - X Duration of cooking - - - - X

Losses on cooking - - - - X

Fat content - - - - X

5. Preserved product

Odour, colour - - X - . -

T a s te - - X . - -

T e x tu re - - X - -

6. Dehydrated puree (flakes)

Odour, colour - - - - X

T a s te - - - - X

(X = test carried out) POTATOES IN BELGIUM 77

TABLE IV. SUMMARY OF THE GENERAL CONDITIONS AND VARIABLE PARAMETERS OBTAINING IN THE VARIOUS TESTS

T e s t N o . I II III IV V

Y e a r(s) 1 9 5 8 - 6 0 1 9 6 6 - 6 8 1 9 6 7 - 6 8 1 9 6 9 - 7 0 1 9 7 0 - 7 1

Total quantity ± 1 80 2 0 0 ± 1 00 ± 7 5 6 0 0 irradiated (kg)

Storage temperature (°C) 7 - 1 2 or 4 and 4 and 8 - 1 0 8 - 1 2 b 1 8 - 2 0 15 7 - 8 a

Duration of storage (weeks) 47 2 0 2 4 2 8 2 8

Source of radiation 60 C o c 137 C s c 137 C s c “ C o c

•Irradiation dose(s) (krad) 5 , 1 2 , 2 0 1 - 1 0 8 - 1 0 8 . 5 8 . 5

Dose rate (krad/h) 4 8 0 - 5 5 0 0 . 4 5 1 5 0 - 1 8 0 d ± 8 d 3 0

Ratio dose rate in relation to 3 / 1 1 /4 0 0 1 1 / 2 2 1 / 6

test III = 1

R eferen ces [ 3 , 1 0 , 1 1 ] [ 1 2 ] [ 13 - 15] [ 1 6 , 1 7 ] [ 1 8 , 1 9 ]

a Four weeks at 4°C and 20 weeks at 7-8°C ; 8 -ll°C for the 'preserves' test,

b Temperature very variable for the industrial test.

c Installations - I: Gamma cell. M ol Centre for Nuclear Studies; II: University of Liège (Professor Bacq);

III: IRMA, IRAD campaign; IV: Wageningen; V: И ТА, Mol Centre for Nuclear Studies. ** Average (continuous irradiation).

Overall result

Some increase in blackening after cooking was found, the immediate origin or cause being as yet unclear.

2.2.2. Test No.II

Quantitative aspect

A dose of 8 krad administered at a low rate (0.45 krad/h) could not prevent sprouting irreversibly.

Qualitative aspect

Blackening after cooking was enhanced by the combined action of irradiation (at a low dose rate) and temperature. 78 SCHIETECATTE and NYS

Overall result

The overall result of low-intensity radiation is markedly negative, and even appears to accentuate the dependence of the tuber on the ambient temperature.

These results were compared with those of tests carried out at a higher dose rate (Test No.III); the comparison showed a dose of 7 to 8 krad to be the theoretical optimum dose and, at the correct intensity, sufficient to produce irreversible inhibition of sprouting. The same comparison also made it possible to distinguish two quite distinct effects:

(a) An effect on the meristematic cells, i.e. an effect intimately associated with sprouting and one whose reversibility or irreversibility is a function of radiation intensity (b) An in-depth effect, which acts on the internal biochemistry of the tubers; certain aspects of it are certainly of a transitory nature. The conclusion drawn from the comparison was that the irradiation treatment of tubers provides less selectivity than had been expected.

2.2.3. Test No.III

The purpose of this test was to make a comparison with chemical treatment based on IPC and CIPC and to study the secondary effects, if any, on the value of the potato - after a relatively long period of preservation - in household and industrial application. The gamma-ray treatment was carried out in an irradiator having an output and dose rate comparable to those of some future industrial type. The tests were carried out during the IRAD campaign organized by Bureau Eurisotop.

Quantitative aspect

The quantitative result was favourable to irradiation, for one thing because of reductions of the respiratory quotient. This final favourable result was obtained by maintaining the preservation temperature after irradiation at 12 to 15°C for 2 to 3 weeks and reducing it thereafter to 7 to 8°C. The higher percentage of spoilage in the industrial test has focused attention on the effect of knocks and handling.

Qualitative aspect

The results showed good culinary stability, although the specific effect is not identical for the two treatments. Irradiation proved to be less selective than dusting with powder (chemical method). The results show that the optimum period for using the irradiated food is between the first and third month after treatment. It has also been observed that the type of use and the colour of the flesh are relatively little affected by any kind of treatment against sprouting. The same is not true of appearance when served and the degree of blackening after cooking. In comparison with an untreated reference sample, the irradiated sample was found to be inferior over a rather POTATOES IN BELGIUM 79 long period of 6 to 10 weeks; the appearance was greyish and the general colouring less pure. The degree of blackening after cooking was lower in the case of the batch treated chemically. It should also be mentioned that the results for the various batches varied quite substantially.

Industrial aspect

A marked browning of potato crisps was noticed for two or three weeks after irradiation treatment, and again after the eleventh week. The industrial yield of crisps remained unchanged. In the case of homogeneous treatment, which is particularly important for irradiation, storage at the correct temperature (8 to 10°C) is likely to improve the appearance of pre-cooked chips. As regards industrial preparations for canning, no unfavourable effect was observed on density, peeling losses or organoleptic characteristics of the products.

Overall results

As a general conclusion it will be noted that irradiation treatment against sprouting does not change the basic principles of proper preservation.

2.2.4. Test No.IV

The reason for holding this test was the need to confirm the results of parallel tests with IPC/CIPC and to investigate the possibilities of treatment on a much larger scale. It was organized by Bureau Eurisotop and conducted on the basis of a pre-designed test procedure for imple­ mentation in co-operation with other countries.

Quantitative results

The comparison showed that the two treatments, which were applied at the same time, had the same effect as regards weight loss. It was found, however, that post-treatment storage conditions could be less rigorous after irradiation.

Qualitative aspect

The culinary assessment is not very different for the various tests. Irradiation does adversely affect the appearance of the cooked products for a time, however. The observations made at the beginning of June, on the other hand, are more favourable to irradiation. Blackening at the beginning of preservation is more pronounced after irradiation. During preservation the situation improves more appreciably than in the case of chemical treatment.

Industrial aspect

It was confirmed that in the case of crisps irradiation is not the superior method for prolonged storage. The quality of pre-cooked chips would be improved in the long term by irradiation treatment. In the case of cooked chips there is a clear advantage. 80 SCHIETECATTE and NYS

Overall result

More than anything else, the results confirmed those of the preceding te s ts .

2.2.5. Test No.V

This test was a repetition of Test IV, which was also organized by Bureau Eurisotop in collaboration with other, foreign institutions. The main concern was to be able to compare the results obtained by the Station with the results of preservation and processing of the product carried out industrially.

Quantitative aspect

With regard to weight loss, the advantage of irradiation was confirmed. As far as the industrial results were concerned, the overall losses were practically the same owing to the poor storage conditions. It should be recalled, however, that during the first weeks after irradiation losses due to dehydration and respiration were accelerated before stabilizing at a level lower than that resulting from chemical treatment. Under normal storage conditions irradiation was found to have a slight advantage as regards losses due to rotting and the percentage of potatoes that could be used at the end of the period. Under not very favourable conditions, i.e. where the temperature and humidity fluctua­ tions were too great, irradiation appeared to enhance rotting. This con­ vinced us of the importance of studying the development of phytopathological risks at an earlier stage. With respect to the chemical picture emerging at the end of preserva­ tion, the increase in sugar (total, reducing and non-reducing) was confirmed; the increase was less than that following the application of Propham-Chlorpropham.

Qualitative aspect

Irradiation resulted in paler flesh, and the degree of blackening after cooking was definitely more pronounced than in the case of dusting with powder. The appearance after cooking was also poorer in view of the greyish hue'Of the irradiated tubers.

Industrial aspec_t

Crisps: The storage conditions remain the determining factor. Irradiation does appear, however, to stabilize the situation better in relation to the quality of the product. Pre-cooked chips: As above. Flakes: Again we found that irradiation held a slight advantage although the purée made from the irradiated batch was found to be greyer. In view of the imperfect storage conditions, no valid conclusions could be drawn regarding the losses observed during industrial processing. POTATOES IN BELGIUM 81

2.3. O verall results

In the light of the overall results, we drew the following conclusions concerning irradiation treatment for the inhibition of sprouting:

(1) The irradiation dose required (7 to 9 krad, Bintje variety) must be applied in an installation capable of achieving a suitable degree of homogeneity. An overdose factor of 2 to 2.5 appears to be acceptable. A higher ratio could result in unfavourable effects; (2) The dose rate has a selective effect on the sprouting power of the tuber. To produce an irreversible effect the dose rate must be sufficiently high. Judging by the results, a mean dose rate of the order of 10 krad/h would be the minimum for an irradiator in continuous operation. (3) The optimum time of irradiation is in principle at the commence­ ment of sprouting, i.e. at the end of the dormant period. Treatment will only be given to tubers whose skins have completely hardened and in which any damaged parts have healed.

In the present state of our knowledge a comparison with chemical treatment based on the use of Propham-Chlorpropham appears to us to be the most suitable. The observations relate to the antisprouting effect proper and the effect on the quantitative and qualitative behaviour during storage.

Quantitative aspect

The effectiveness of the inhibition of sprouting by the two methods is perfectly satisfactory. It should also be noted that gamma radiation does not result in internal sprouting, as is the case with Propham- Chlorpropham. M oreover, if the dose rate is adequate, the anti­ sprouting effect of radiation is irreversible, whereas chemical treatment entails permanent contact between the tuber and the active material. For this reason, tubers duly dusted with powder are not suited to transport or prolonged handling. When irradiation involves damaged, unhealed tubers, there is a risk of substantial losses due to m icrobiological changes. Handling during and after irradiation is also harmful (bruises). At the end of the preservation period the percentage of usable tubers is slightly higher for irradiation, which gives an increase of the order of 3 to 5%. A further positive aspect is the lower sensitivity of irradiated tubers to a substantial increase in temperature at the end of storage.

Qualitative aspect

Irradiation increases blackening after cooking, particularly in the first weeks after treatment. A more or less greyish colour also detracts from the appearance of the cooked potato.

Industrial aspect

In crisps and chips an increased tendency to browning is observed (Maillard reaction) when the raw material (raw tuber) has just been 82 SCHIETECATTE and NYS irradiated or after prolonged storage. The greyish appearance is also observed after normal cooking. The other organoleptic aspects are difficult to differentiate or show a slight advantage on the side of irradiation.

3. DISCUSSION OF THE RESULTS

3.1. Comparison of irradiation with the Propham-Chlorpropham method

The results obtained in Belgium relate to three distinct matters:

(1) The anti-sprouting effect and selectivity of treatment with respect to the tuber (2) ' The technical problems proper (3) Economics.

In this section we shall continue the comparison with chemical treatment.

3.2. Quality of the product treated

The two processes (physical and chemical) are applicable on an industrial scale. Irradiation is the obvious method where legislation against all chemical treatment exists. If both processes are sanctioned, in the light of our observations so far, irradiation can hardly be competitive in view of its lower selectivity. The argument claiming greater sensitivity with respect to variety does not hold as the choice of variety cannot be modified on this basis. Nor are the quantitative and qualitative advantages of irradiation at the end of storage enough to change this situation. Large-scale tests are still required to confirm whether and in what way gamma rays affect the development of certain preservation diseases.

3.3. Technical aspect of treatment

Time and place of treatment

In the case of chemical treatment the application remains dependent on the mode of treatment. In the case of dusting with powder, which is fully effective if not the most selective method, treatment should preferably be carried out when the tubers are put into storage. The application of aerosols and fumigation makes possible more flexible treatment as often as required and at the desired dose. Irradiation on the other hand is carried out once only, at the optimum time. This treatment requires transport to and transfer through an installation, which should preferably be adaptable or completely suited to the treatment of potatoes.

Installation

Industrial installations suitable for the application of powder or aerosols are known and no longer present’any particular problems. Ю ТА TOES IN BELGIUM 83

Chemical treatment for the inhibition of sprouting is within the capability of all. On the other hand, specific types of irradiation installations specially designed for the treatment of potatoes have not yet been intro­ duced. The basic technical specifications are quite well-known, but in view of the difficulties and uncertainties with respect to the choice of a handling and packing system, the ideal design of an industrial installa­ tion is still in the first stage of development. A compromise must be found between a system of handling that makes it possible to avoid knocks and damage and a design that also ensures an adequate energy yield. For various reasons the technical and economic requirements are not'comparable with those associated with chemical treatment. Siting in itself entails overcoming a substantial problem in view of the transport required. So far it is gamma radiation that has been the particular subject of various technological studies and research. Starting from the fact that the action in depth of gamma radiation produces undesirable biochemical changes and that surface action, which is clearly more selective, is capable of producing the same results from the point of view of the inhibition of sprouting, consideration might be given to the use of electron accelerators. The problem would be no less complex, however, as regards handling of the raw material and the application of a sufficiently homogeneous dose. The principle nevertheless deserves more attention.

Dose and dose rate

Although the risks of an overdose of chemical products are obvious and a function of various possible modes of application, the irradiation dose is known and easily controllable; for a particular installation of an acceptable design the overdose remains constant. Repeat doses are not possible. The dose rate is important, and a minimum must be respected. An industrial installation must ensure a sufficiently high dose rate, which we consider to be 100 to 200 krad/h for the case of gamma radiation from radioisotope sources.

Homogeneity

The homogeneity of chemical treatment is above all a function of the mode of application. Dusting with powder can give rise to problems, whereas in the case of gamma irradiation one can be sure that the dose is distributed homogeneously throughout the mass. We have seen, however, that deep irradiation of the tuber is not necessary for the inhibition of sprouting.

P a ck in g

In the two systems the requirements with respect to storage conditions must be fulfilled. In the case of irradiation there is more flexibility at the end of the storage period, which is an unquestionable advantage in countries with a warm climate. 84 SCHIETECATTE and NYS

R esid u es

The IPC/CIPC residue permitted in a raw, peeled tuber is of the order of 0.5 ppm. This amount is not reached when products have been treated with the correct and uniform dose [20]. A greater problem in this connection is pollution by waste water discharged by the processing industries. In the case of irradiation there is no danger of radioactive residues; the difficulties relate to matters of legislation and the different require­ ments and attitudes of health authorities with respect to research to be undertaken. It would be desirable in the short term for a favourable recommendation to be made by the World Health Organization.

Availability of the product

When chemical treatment is applied there are no limitations. Irra­ diation does have the drawback that the irradiated tuber is unavailable for 4-6 weeks after treatment.

3.4. Economic aspect of the process

It is rather difficult at present to compare the cost of the two types of treatment and to draw final conclusions. The irradiation installations have not yet reached the same level of development as plant used for chemical treatment. The radiation sources entail further substantial investment. According to a recent study carried, out in the Netherlands, investment in a cobalt-60 installation could be estimated to be roughly 40-60% higher on average than that for an installation for chemical treatment, mainly due to the complementary and higher costs for infrastructure. Thus, one arrives at a cost 50-100%) higher, depending on the system adopted [21]. When use is made of a gamma irradiation installation there are several requirements that have to be fulfilled. The normal way of keeping processing costs down is to ensure that the installation has a high utiliza­ tion ratio; the annual throughput of raw material in continuous operation should be as high as possible. In the case of potatoes it is found to be impossible to meet that requirement. The campaign may be expected to extend over 2-3 months at the most. In principle, therefore, it would be necessary to design a multi­ purpose installation, a task which would necessarily entail problems of a technical nature. As regards the annual tonnage, we can be more specific. The estimate of the amount of potatoes to be stocked over a long period in Belgium is of the order of 500 000 tonnes per annum. This corresponds to approximately 40% of the annual consumption [22]. For purely practical reasons the treatment of 50 000 tonnes per annum by a gamma irradiator may be considered to be an absolute maximum. If one considers a run of 10 weeks for 5 days a week and 16 hours a day, an irradiator of this kind will operate at a rate of approximately 1 tonne per minute. On that basis we arrive at a requirement of some 10 irradiators for Belgium. Transport of the material to be irradiated to the place of treatment may be considered as an unfavourable economic factor. This aspect POTATOES IN BELGIUM 85 should nevertheless be considered in the context of improved organiza­ tion and distribution of stocks. The secondary advantages of irradiation treatments against sprouting, such as the reduction of overall losses, quality safeguards, the stabilizing influence on the market and the possibility of the development of the processing industry are factors whose importance can be established only by means of a specialized economic study.

4. PROBLEMS OF MARKETING

Factors likely to hinder the introduction of the irradiation of potatoes have already been referred to during the discussion of the results. We can summarize the technical advantages of the process as follows:

Irreversibility Controlled dose Counteracting the development of certain preservation diseases Absence of residues.

Mention may be made of several secondary economic effects, which are not without significance since the process can help the processing industries to achieve rational operation and can also have a stabilizing effect on the prices of the finished product. The advantage of the process from the health point of view can also be stressed. Let us therefore examine the reasons why in Belgium there has been a delay in developing the process for the irradiation of potatoes and the marketing system which would result.

4.1. Choice of product

The potato is of low commercial value but is nevertheless a staple food. As a raw material it is perishable and shortages at the end of the period of consumption can result in sharp increases in the price. More­ over, the raw material is not available all the year round and has to be treated during a rather short period, which constitutes a substantial obstacle to economic irradiation.

4.2. Technical possibilities

From the technical point of view gamma-radiation treatment is quite feasible but it is still necessary to carry out development work in a pilot installation on some aspects. This is the only way in which producers, wholesalers and industrialists can arrive at a precise appreciation of the advantages. On the other hand, chemical treatments cannot be discarded; it must be recognized that they are indispensable in num erous cases and that they yield fully satisfactory results. There is, therefore, no real need to replace them in Belgium. It should also be mentioned that the public health authorities have given complete sanction for their use. 8 6 SCH IETEC AT TE and NYS

4.3. Economic possibilities

In the commercial sector the need for a new process has not been felt, possibly because of lack of information. Furthermore, the overall processing cost, which is clearly higher than that of chemical treatment, is certainly not attractive. The effort necessary to achieve acceptance of an irradiated product by the consumer does not appear to us to be a very substantial obstacle. . The siting of the installation does not pose any real economic problem either; the installation should be planned with centralization in mind.

REFERENCES

[1] DE PROOST, M ., Nouvelles méthodes de stérilisation par les radiations nucléaires (New methods

of sterilization by nuclear radiation), CEN Rep. R.1459 (1958).

[2 ] DE PROOST, М ., Installations d’irradiations gamma et recherches sur la préservation des aliments

par irradiations gamma au CEN, M ol (Gam m a irradiation installations and food preservation by gamma irradiation at CEN, M ol), Irradiat. Aliments 2 1 ( 1 9 6 1 ) . [3] KIRCHMANN, R., DE PROOST, M ., DEMALSY, P., RODERBOURG, J., NYS, L ., Etude du

comportement de quelques variétés belges de pommes de terre soumises à l’irradiation gamma

(Study of the behaviour of some Belgian varieties of potato subjected to gamma irradiation),

CEN Rep. BLG 126 (1962).

[4] MANIL, P ., Radiostérilisation et radiopasteurisation des aliments (Radiosterilization and radio- pasteurization of food products), Institut Agronomique de 1‘Etat, Gembloux (1960).

[5] LIEVENS, F ., Récents progrès dans l'application de l’énergie nucléaire en agriculture (Recent advances in the agricultural applications of nuclear energy) CEN Rep. BLG 167 (1962).

[6] CONSTANT, R ., La sterilisation des aliments par les radiations ionisantes (Sterilization of food by

ionizing radiation), Farmaco 19 1 (1964).

[7] BOLLY, L ., L'irradiation des denrées alimentaires en Belgique (Irradiation of food products in

Belgium), Bull. INACOL 18 10 (1967).

[8] MARTH, P .C ., SCHULTZ, E .S., Am. Potato J. 27 (1950)23. [9] SPARROW, A .H ., CHRISTENSEN, E ., Improved storage quality of potato tubers after exposure to 60 Co gammas, Nucleonics 12 8 (1954). [10] NYS, L ., L’irradiation des pommes de terre (The irradiation of potatoes) Bull. INACOL ¿8 10 (1967). [11] NYS, L ., "Conservation et irradiation des pommes de terre" (Preservation and irradiation of potatoes). Techniques d’irradiation, Cah. Inf, Bureau Eurisotop No. 30 (1967).

[12] NYS, L ., "L’intensité de l’irradiation aux rayons gamma et ses effets sur le tubercule" (Intensity of gam m a irradiation and its effects on tubers), E. A, P, R. 4e conf. trisannuelle, Brest (1969). [13] NYS, L ., Le traitement antigerminatif des pommes de terre: étude comparée de l’irradiation et

du poudrage chimique (Anti-sprouting treatment of potatoes: comparative study of irradiation and chemical powder dusting). Bull. INACOL 20_ 6 (1969).

[14] BOLLY, L ,, B1STON, R ., Irradiation des pommes de terre destinées à l’appertisation (Irradiation

of potatoes prior to appertization), Bull. INACOL 20 7 (1969).

[15] NYS, L ., "Incidence d’un traitement antigerminatif sur les caractères technologique et culinaire

du tubercule" (Effect of anti-sprouting treatment on the technological and culinary characteristics

of tubers), L’irradiation des pommes de terre (Proc. Symp. 1969), Cah. Inf. Bureau Eurisotop No. 45

( 1 9 6 9 ) . [16] NYS, L ., Essais techniques sur l’irradiation des pommes de terre, campagne 1969-70 (Technical

tests on potato irradiation, 1969-70 campaign), Rep. Station de Haute Belgique, Libramont (1970).

[17] . SANDRET, F ., Technologie de la radio-inhibition de la germination des pommes de terre. Rapport

sur les essais de laboratoire de la campagne 1969-70 (Technology of radioinhibition of sprouting in potatoes. Report on laboratory tests for the 1969-70 campaign), Cah. Inf. Bureau Eurisotop N o.44(l971).

[18] NYS, L ., Etude semi-industrielle des traitements antigerminatifs, essais communautaires Eurisotop

1970-71 (Pilot-plant study of anti-sprouting treatments. Eurisotop community tests, 1970-71),

Rep. Station de Haute Belgique, Libramont (1971). POTATOES IN BELGIUM 87

[19] SAND RET, F ., Technologie de la radio-inhibition de la germination des pommes de terre. Essais technologiques à l'échelle pilote semi-industrielle (campagne 1970-71) (Technology of radioinhibition

of sprouting in potatoes. Technical tests on semi-industrial pilot scale (1970-71 campaign)), Bureau

Eurisotop (1972), [20] MARTENS, P. H ., NYS, L ., BISTON, R., FRASELLE, J ., Propham, Chlorpropham et pomme de terre (Etude de résidus) (Propham, Chlorpropham and potatoes (residue study)). Bull. Rech.

Agronom. Gembloux 1-2(1971). [21] SPARENBERG, H ., Studie betreffende het bestralen van aardappelen in de praktijk (Study of potato

irradiation in actual practice), Meded. I.B . V. L ., Wageningen, No. 374 (1971).

[22] Documentation de la Station de Haute Belgique (Documentation of the Haute Belgique station).

PROSPECTS OF ONION IRRADIATION IN INDIA

P. SUDARSAN Programme Analysis Group, Department of Atomic Energy, Bombay, India

Abstract

PROSPECTS OF ONION IRRADIATION IN INDIA. The econom ic feasibility of reducing post-harvest lo sses of onions by a sprout-inhibiting dose (6 krad) of gamma radiation is discussed with special reference to a promising location. India is a major onion producing and exporting country. Significant losses due to sprouting, rotting and dehydration during storage and trans­ portation constitute a serious problem . Laboratory and field storage trials showed that storage losses may be reduced considerably by irradiation. A transportation trial indicated that consignments despatched by rail, involving long transit periods to distant consumption centres in winter, may similarly benefit from radiation treatment. Analyses of production seasonality, price fluctuations and likely monetary benefits to farmers and traders show that onion irradiation may induce storage in larger quantities for longer periods, and increase despatches to distant markets within the country and abroad. Analysis of demand for onion irradiation in a promising location showed that a com m ercial irradiator could be operated for eight consecutive months at about 50% capacity utilization, considering only the demand for internal consumption. On this basis a preliminary cost-benefit analysis showed that high returns on investment may be expected for the economy as a whole and for potential entrepreneurs. If onion farmers are to benefit directly from the project, it should preferably be operated as a service irradiator, whose profitability would be less, and certain infrastructural facilities would need be strengthened or provided. Profitability would increase substantially if exports are permitted.

The likely impact of an onion irradiator on production, market arrivals, price fluctuations, and on neighbouring village markets is discussed. The socio-economic and commercial factors affecting economic feasibility are detailed. The possible relevance of the study to other developing countries is explained and the need for greater collaboration in all aspects of food irradiation among groups of countries such as developing countries with similar needs, conditions and problems is discussed.

1. INTRODUCTION

The feasibility of reducing post-harvest losses in onions by sprout- inhibiting doses of gamma radiation (6-15 krad) has been investigated extensively by various workers with promising results. Laboratory studies in India at the Bhabha Atomic Research Centre (Trombay, Bombay) had shown that a dose of 6 krad inhibits sprouting of onions at ambient tempera­ ture (26-32°C) [1-3]. The laboratory investigations were followed by scaled-up studies (field storage and transportation trials) [4, 5] and studies to assess the economic feasibility of onion irradiation in India [6-8]. The present paper examines the economic importance of onion production to the country and the need to reduce post-harvest losses; summarizes the laboratory and scaled-up researches; explains the investigations pertaining to economic feasibility; and discusses the prospects and problems in the practical application of onion irradiation in India. Special emphasis is placed on a detailed study of the economic feasibility of onion irradiation in a promising location [8]. It is understood that only one m icro-level analysis [9], pertaining to economic feasibility of onion (and potato) irradiation in

89 90 SUDARSAN

Israel, has been published so far. Among developing countries similar feasibility studies for onions or potatoes are not known to have been carried out, with the exception of the study for onions in India [8]. This paper may therefore be useful for discussing the economic feasibility of radiation preservation of semi-perishable agricultural commodities, with particular relevance to the conditions and practices in a developing country.

2. ECONOMIC SIGNIFICANCE OF ONION PRODUCTION IN INDIA AND THE NEED FOR REDUCING POST-HARVEST LOSSES

In India onions are consumed both as a relatively inexpensive vegetable and as a spice for seasoning. The per capita consumption of onions in the country is about 2 kg/а. With an annual production of about 1. 5 million tonnes in recent years, India is the world's largest producer of onions. On an average about 9% of this production is exported. In 1970 about 130 000 tonnes were exported, fetching approximately Rs. 40 million (US $ 5.33 million). Onions alone account for about 70% of Indian export earnings in the 'fresh fruits and vegetables' category [10]. The available estimates of post-harvest losses during storage and transportation indicate that total losses through sprouting, rotting and dehydration may be 20 - 30% of the annual production. Considerable storage losses occur in Rabi (summer-harvested) onions, which are stored in ambient conditions for periods up to three months after harvest and sun-cured in traditional storage facilities called chawls1. Significant losses in quantity and quality are reported to occur in consignments of Khariff (winter-harvested) onions, which are despatched by rail from Nasik District to distant consump­ tion centres in Assam, in the Northeast of India (Fig. 1). According to experienced traders, about 50% of the onions are sprouted when they reach their destinations in Assam. The usage of chemical sprout inhibitors for onions is not practised in India. Reduction of po^t-harvest losses would significantly increase the total availability for internal consumption and exports. Reduction in storage losses may induce storage of greater quantities for longer periods. Subsequent releases of produce to the consumption centres, when prevailing prices are high, may increase the earnings of farmers and traders alike. The extension of the period of distribution may reduce price fluctuations to some extent, thus benefitting the small farmers and consumers. Reduction of transportation losses may extend or enhance the sales to distant markets within the country and abroad.

1 Chawls ate storage sheds with thatched, tiled, or corrugated asbestos sheet roofs. Onions are stored

4 to 5 feet deep on false-bottom platforms made of bamboo or ’ carvi* twigs (a local plant), which protect the bulbs from direct contact with the soil. The sides of the chawls are covered with bamboo or carvi twigs, which provide natural ventilation and reduce build-up of humidity and temperature pockets inside the onion heaps.

Chawls are built with á maximum capacity of 60 tonnes. The rental charge is between Rs. 15-20 (US$ 2-2.66) per tonne, depending on the period of storage. ONIONS IN INDIA 91

FIG. 1. Map of India showing Nasik District (inset: Lasalgaon in Niphad Taluka of Nasik, where the field storage

trial was held) and Dibrugarh in Assam , where the transportation trial was held, the onions being brought there from Trombay.

3. FIELD STORAGE AND TRANSPORTATION TRIALS AND LABORATORY EXPERIMENTS IN INDIA

3.1. Field storage trial of Rabi onions in India

During 1971 a field trial was conducted in an important centre of onion production, Lasalgaon in Nasik District, situated about 250 km from Trombay (Fig. 1). In this experiment approximately 320 kg of Rabi onions 92 SUDARSAN

TABLE I. FIELD STORAGE TRIAL OF CONTROL AND IRRADIATED RABI ONIONS IN LASALGAON

T o t a l

sto ra g e Sprouted Rotted Dehydration Total losses T r e a t m e n t p eriod a (<7°) (%) (%) (% > ( m onths)

2 C o n tro l 5 . 5 4 . 5 6 . 0 16

2 Irradiated 2 . 8 1 . 8 5 . 4 1 0

(m in. 6 krad)

3 C o n tr o l 8 . 8 1 0 . 2 1 9 . 5 3 8 . 5

3 Irrad iated 1 . 7 4 . 0 1 5 . 1 2 0 . 8

(m in. 6 krad)

4 C o n tro l 5 . 6 1 4 . 2 3 1 . 2 5 1 . 0

4 Irradiated 0 . 0 7 . 1 2 4 . 0 3 1 . 1 (m in. 6 krad)

Approximately 320 kg of onions were irradiated one month after harvest and curing to a minimum

dose of 6 krad. An equal amount was kept as control. Total losses due to sprouting, rotting and dehydration were more in unirradiated controls. Source: unpublished BARC data.

a Includes post-harvest storage of one month prior to treatment.

obtained one month after harvest were irradiated to a minimum dose of 6 krad in a 60Co package irradiator (overdose ratio 1:1.6) located at the Bhabha Atomic Research Centre in Trombay. The irradiated onions, along with an equal quantity of unirradiated controls, were transported by truck and stored according to the conventional storage practice in an experimental chawl in Lasalgaon. The results of this trial [ 4] are reproduced in Table I. The results showed that losses due to external sprouting in unirradiated lots were not as high as envisaged from earlier laboratory studies [1,2]. However, the total losses due to sprouting, rotting and dehydration were considerably reduced by irradiation. Thus savings in total losses as a result of irradiation were approximately 6% at the end of two months, 18% at the end of three months and 20% at the end of four months. The higher dehydration loss in controls has been attributed [ 3] to (i) the relatively higher rate of sprouting in control tubers with the sprouts continuing to grow during storage, whereas in irradiated bulbs the sprouts, which are apparent during the first two months, subsequently wither and drop off; and (ii) increased rotting, contributing to increased loss of water from bulbs. A third possibility mentioned is the greater internal sprouting in control bulbs [3]. A random examination of control and irradiated bulbs at the end of this storage trial showed about 80% internal sprouting in control bulbs as against only 5% in irradiated. Traders at Lasalgaon who examined both lots indicated that the un­ irradiated onions were in a marketable condition up to three months' storage and the irradiated lot up to four months. Beyond these periods the onions may not be marketable on account of their poor appearance. ONIONS IN INDIA 93

TABLE II. ACCEPTABILITY OF RED GLOBE ONIONS IRRADIATED 7 DAYS AFTER HARVESTING AND STORED AT 20°C FOR 165 DAYS

Q u a n tity C o n tro l 6 krad 12 krad 2 5 krad Fresh control

A p p e a r a n c e 2 . 6 7 5 . 4 1 6 . 0 8 4 . 7 5 6 . 6 7

O dou r 4 . 5 5 . 9 9 5 . 5 5 . 5 7 . 0 8

T e x tu r e 3 . 4 6 . 5 6 . 5 5 . 5 7 . 4

O v e r a ll 2 . 0 5 , 5 5 . 6 4 . 7 5 6 . 6 acceptability

Taste panel consisted of 12 members. Preference rating based on 9-point hedonic scale. A score of

5 .5 or above is considered acceptable [3 ].

3.2. Laboratory investigations

Studies at Trombay [ 3] showed that when onions two months after harvest were irradiated to 6, 10 and 15 krad and stored at varying temperatures, irradiation at all dose levels caused an initial acceleration of sprouting at all storage temperatures. Storage at low temperatures or alternating high and low temperatures was found to accelerate sprouting of both irradiated and unirradiated onions. In all these cases maximum sprouting occurred at 10°C followed by 4 and 20°C, the least being at room temperature (27 - 30°C). Subsequent studies [ 3] revealed that (i) a dose of 6 - 12 krad used shortly after harvest gives excellent sprout inhibition and the effect of these doses is weak or nil when used at a later date, (ii) discoloration of the growth centre is noticed about two months onwards from the start of storage in irradiated bulbs stored at 20°C and becomes more intense with increased storage time. Approximately 80% of the bulbs irradiated 14 days after harvest and stored for five months showed internal discoloration. In most cases the discoloration was accompanied by rotting of the growth centre, especially in bulbs irradiated to 12 and 25 krad. Maximum internal rotting was noticed in bulbs irradiated to 25 krad, which increased with increasing lapse of time between harvest and irradiation. Results of these studies suggested that since discoloration and rotting of the growth centre increases with increasing time between harvest and irradiation and also at higher doses, a dose of 6 krad given soon after harvest before any internal sprouting commences may reduce the percentage of such bulbs. In the majority of onions irradiated to 6 krad soon after harvest this discoloration constituted only a very limited part of the whole bulb and may therefore not be objectionable for most purposes [3]. This contention was supported by a taste panel evaluation, reproduced in Table II.

3.3. Transportation trial

A transportation trial using approximately one tonne of Khariff (winter- harvested) onions (half irradiated 6-9 krad; half unirradiated) was conducted by rail between Bombay and Dibrugarh in Assam (Fig. 1). The onions were packed in 40-kg lots in jute bags. The consignment was despatched in late January and reached Dibrugarh in late February, after a transit period of 94 SUDARSAN nearly one month during winter. Examination at destination revealed that 50 - 80% of the unirradiated onions had sprouted. Though 10 - 15% sprouting was observed in irradiated lots, the sprouts were not viable, drying up and dropping off. Random examination of good onions for internal sprouts showed that 60 - 75% of controls had internal sprouts, as against 25% in irradiated onions. Internal sprouts in controls appeared to be viable, while those in the unirradiated onions were not [ 5]. These results corroborate the laboratory finding that sprouting is accelerated at low temperatures and the reports of traders in Lasalgaon and Assam regarding excessive sprouting in consignments of Khariff onions. Traders in Dibrugarh who examined the two lots indicated that if reproducible results could be ensured, they may be willing to pay 15 - 20% higher prices for irradiated onions.

3. 4. Implications of results to practical feasibility

The implications of the above findings for the practical feasibility of onion irradiation in India are: (a) Under existing storage practices (in chawls) onions requiring two to four months storage or storage in areas where the diurnal temperatures fluctuate widely may benefit significantly from radiation treatment. (b) Onions required for transportation involving extended transit periods during the cooler months would also benefit from radiation treatment. • (c) Post-irradiation storage facilities for storage at temperatures less than ambient may not be necessary. This would be a favourable economic fa c to r . (d) It is preferable to irradiate onions as soon as possible after harvest and curing. This may reduce the operational flexibility of commercial onion irradiators. (e) To maximize the effectiveness of sprout inhibition and to minimize internal discoloration, the dose delivered should be about 6 krad, with the minimum overdose technologically feasible.

4. ECONOMIC FEASIBILITY OF ONION IRRADIATION IN INDIA

4.1. Preliminary studies

Prior to the field trials a macro-study [ 6] was undertaken to make a preliminary assessment of the economic potential of onion irradiation in India and to indicate area-wise priorities for carrying out a more detailed micro-study. The macro-study showed that onion irradiation may be econom ically feasible in India and a potential to irradiate about 10% of the annual crop may exist. The study indicated that Nasik District, which produces about 220 000 t or nearly 15% of the country's annual onion crop, could be selected for intensive analysis. The subsequent micro-study of Nasik District [ 7] identified Lasalgaon village, which is a major onion assembling market in Niphad Taluka2, as the location where onion irradiation may have the maximum economic potential and recommended a detailed feasibility study for an onion irradiator at this location (Fig. 1).

z Talukas ate administrative divisions within a District. ONIONS IN INDIA 95

4.2. Feasibility study

Accordingly, an economic feasibility study was carried out in Lasalgaon [ 8] in co-ordination with the field storage and transportation trials cited earlier. The following objectives were formulated based on the experience gained from the preliminary economic studies [6, 7]; (i) Detailed quantitative estimation of the potential demand for onion irradiation in Lasalgaon, from an analysis of seasonality of production, market arrival and despatch, price fluctuation and anticipated monetary benefit of the process to likely users. (ii) Determination of the optimal capacity (t/h) of a future commercial irradiator at Lasalgaon. (iii) Preliminary cost-benefit analysis of the project. (iv) Identification of the infrastructural facilities that might require to be strengthened or built up to ensure practical feasibility. (v) Assessment of attitudes of local traders and farmers, their co­ operatives, the local market regulation institution and agricultural promotion agencies at the district and state level, with regard to the feasibility of onion irradiation. (vi) The likely impact of an irradiator in Lasalgaon on traditional marketing, storage and distribution practices. Considerable interest was expressed in this project by the organizations cited in (v) above, and the study was carried out with their co-operation. The field storage and transportation trials were partly financed by the farm er's co-operative and the local market regulation committee, comprising prominent growers and traders. The following is a simplified analysis of the economic feasibility of onion irradiation in Lasalgaon, based on the m acro- and m icro-studies [ 6, 7] and the economic feasibility study [8].

4. 3. Production foci

The concentration of onion production in Maharashtra State within the country, in Nasik District within Maharashtra, and in Niphad Taluka within Nasik District, is shown in Table III. Within Niphad Taluka, the two villages of Lasalgaon and Pimpalgaon (Fig. 1) have annual market arrivals of 75 000 and 45 000 tonnes, equivalent to 5% and 3% of the national production, respectively. In Lasalgaon arrivals comprise large quantities of both Khariff (winter- harvested) and Rabi (summer-harvested) onions, while in Pimpalgaon the arrivals are predominantly Rabi onions. The substantially larger market arrivals and the longer marketing period for fresh produce in Lasalgaon, as compared to Pimpalgaon, led to the choice of the form er location for carrying out the economic feasibility study [3].

4. 4. From the field to the consumer

The present distribution system for onions in India, and particularly in Nasik District, is illustrated in Fig. 2. In Nasik District, as in other parts of the country, onions are harvested manually and cured for about 10 to 15 days in the fields. Depending on the resources and financial needs of the farmer, Rabi onions may or may not be stored before transport to 96 SUDARSAN

TABLE III. CONCENTRATION OF ONION PRODUCTION IN INDIA

Approximate annual A l l In dia

R e g io n prod uctiona p ro d u ctio n

( t ) m

In d ia 1 5 0 0 0 0 0 1 0 0

Maharashtra State 5 2 5 0 00 3 5

Nasik District 2 2 0 0 0 0 15 (Maharashtra)

Niphad Taluka. 1 3 5 0 0 0 9 (Nasik District)

Lasalgaon village 7 5 0 0 0 5 (Niphad Taluka)

Pimpalgaon village 4 5 0 0 0 3 (Niphad Taluka)

a Figures are estimates for 1971.

HARVEST I .PRODUCERS STORAGE .

SA LE 10 FARMERS* OQ-OPERATIVE

PRODUCE ASSEMBLING MARKET 1 SALE TO VILLAGE TRADERS ■+— \ VILLAGE TRADERS' STORAGES (CHAWLS) HEAR ASSEMBLING MARKET I -► SALES TO TRADERS IN MAJOR DISTRIBUTION AND CONSUMPTION CENTRES I TRADERS' STORAGES IN ABOVE CENTRES I WHOLESALES (CITY MARKETS) I RETAILERS (VEGETABLE VEtOORS AT RETAIL MARKETS, OtOCERY AM) PROVISION STCHES) t CONSUMER

FIG.2. Present onion distribution system. ONIONS IN INDIA 97 the assembling market. Khariff onions are brought to the market without any storage. About 70 to 80% of the produce intended for marketing arrives in the regulated markets, while the rest is sold directly to traders (field purchases). The onions are brought to the assembling markets by the * farmers in bullock-carts, tractor-trailers or trucks, mostly in bulk but also in jute bags. In the assembling yards in Nasik District the onions aré sold to village traders by open auction, supervised by the local market regulation committee. The Rabi produce is stored for periods up to three months in the traders' chawls and periodically during storage rotted or sprouted onions are sorted out manually and discarded. Before sale to traders at consumption centres, the onions are graded according to size and quality. Graded onions are packed in wide-mesh jute bags in lots of 40 or 80 kg and despatched by truck or rail to consumption centres within the country. Onions despatched from Nasik District by rail are transported in specially modified wagons with improved ventilation. Export consignments are packed in 20 kg bags and despatched by truck to Bombay port for shipment. At consumption centres onions are kept by retailers in jute bags or wooden boxes and sold loose to consumers. Consumers generally buy small quantities to meet weekly or fortnightly needs, and storage losses at house­ holds may be negligible. 'Nasik' onions (Red Globe variety), with their characteristic spherical bulbs, maroon skin, and high pungency, enjoy a distinct consumer preference in many parts of the country and in the export markets in southeast Asia, Ceylon and the Gulf countries in West Asia.

4. 5. Production seasonality

There are two important onion crops in India. The Khariff crop is sown between May and August and harvested from October to January. Fresh Khariff onions arrive in the produce assembling markets near the production centres from mid-October to mid-February. Khariff onions are grown mostly in Maharashtra with concentrated production in Nasik District. The Rabi crop is sown between October and December and harvested in April and May. Market arrivals of fresh produce extend from mid-April to mid-June. In addition there is also a minor crop composed of late Khariff and early Rabi, called Rangda. Thus there are continuous arrivals of fresh onions for eight months from mid-October to mid-June in the produce assembling markets in Nasik District. This is illustrated in Fig..3, showing the monthly arrivals of onions in the Lasalgaon market. For the country as a whole the Rabi crop is more important, accounting for about 75% of the total production, whereas in Nasik District Khariff production constitutes 75% of the annual crop and Rabi only 25%. In the Lasalgaon market arrivals are approximately 70% Khariff, 9% Rangda3 and 21% Rabi (Fig. 3).

4. 6. Relationship between Khariff production and market prices

The virtual monopoly of Khariff production enjoyed by Maharashtra State, and particularly Nasik District, ensures a high demand for these onions from other States in the country, resulting in higher prices for Khariff onions.

3 In the subsequent analysis Rangda arrivals will be considered as part of Khariff arrivals. 98 SUDARSAN

FIG .3. Monthly onion arrivals and price fluctuations in Lasalgaon market (average monthly figures from

October 1967 to September 1971). Source: Agricultural Produce Marketing Committee, Lasalgaon.

Figure 4 illustrates the high prevailing prices during the Khariff harvest (October to February) as compared to the prices during the Rabi harvest (April and May) in consumption centres such as Bombay, Calcutta, Dibrugarh (Assam) and in the produce-assembling markets such as Lasalgaon. However, soon after the early Khariff produce from Maharashtra State arrives in substantial quantities in consumption centres throughout the country, prices start declining rapidly (Fig. 4). This decline may be attributed to two factors; (i) the pent-up demand in consumption centres is partially satisfied by the early Khariff arrivals, and (ii) Khariff arrivals from Maharashtra from November to February are closely followed by Rangda arrivals in March and large Rabi arrivals from several producing areas, including Maharashtra, between April and June. Thus fresh onions would be continuously available for about eight months from November and therefore prices decline throughout the country during this period (Fig. 4). The relationship between monthly arrivals and prices in Lasalgaon (Fig. 3) illustrates this behaviour of Khariff prices in production centres. ONIONS IN INDIA’ 99

О------О DIBRUGARH 1970-1971

• - - - • CALCUTTA 1968- 1969

О------О BOMBAY 1968- 1970 - • LASALGAON z (Produce assembling market) z о OCT. 1967 TO SEPT. 1971

к z

tu_I <

0 1 ?

о < К ш > <

J------1____I____I____I____I____L OCT NOV DFC JAN FEB MAR APR MAY JUN JUL AUG SEP

FIG.4 . Onion price fluctuations in selected markets. Source: State Agricultural Departments.

4. 7. Storage prospects of Khariff onions

The decline in onion prices for seven consecutive months ensures that Khariff arrivals at the produce-assembling markets are quickly disposed of to consumption centres throughout the country without any significant post­ harvest storage. These considerations show that there is no need for long-term post-harvest storage of Khariff onions in India.

4.8. Need for reducing transportation losses of Khariff onions

Large quantities of Khariff onions are despatched by rail from Nasik District to Assam (Fig. 1) and other parts of Northeastern India involving distances of 1500 to 2000 km and transit periods of 20 to 30 days across the colder regions of the country during the winter months. At present about 10 000 tonnes of Khariff onions are sent regularly between mid-October and mid-March to Assam from Lasalgaon alone. The results of the transportation trial cited earlier corroborated the reports of traders regarding high transit losses (50% sprouting) in these consignments and indicated that sprout inhibition by gamma radiation may reduce these losses substantially. 100 SUDARSAN

In Assam, unlike most other parts of the country, even onions with fairly long sprouts are not thrown away but are de-sprouted and sold at a discount of Rs. 30 to 50 per tonne [ 8]. Traders also have to bear the labour cost of de-sprouting, the loss of weight due to de-sprouting [ 8] and the higher dehydration losses that occur in onions with internal or external sprouts [ 3]. From the viewpoint of traders in Assam and both traders and farmers in Lasalgaon onion irradiation would enable increase in despatches to the highly profitable Assam market. Prices in Assam vary from about Rs. 1000 per tonne in November and December to about Rs. 500 per tonne in April. These prices are much higher than those prevailing in other parts of the country (Fig. 4) and are often higher than the export price, which averages Rs. 500 per tonne.

4.9. Monetary benefits of reducing transportation losses in Khariff onions

It was mentioned that traders in Lasalgaon may fetch at least 15% higher prices for irradiated onions despatched to Dibrugarh (Assam). As reliable details of transactions between traders at the two centres could not be obtained, the market prices at Lasalgaon, which are invariably lower than • prices fetched by the village traders, were used to quantify the monetary benefits of irradiating Khariff produce. It was further assumed that traders in other consumption centres in Assam may also react in the same manner to the reduction of losses in irradiated onions as the traders in Dibrugarh. On this basis, if the 10 000 tonnes of Khariff onions that are despatched from mid-October to mid-March to Assam from Lasalgaon were to be irradiated, the extra income that could be earned by traders at Lasalgaon would be around Rs. 0. 4 million per annum. The estimated cost of irradiation is about Rs. 20 per tonne (to be dis­ cussed later) or Rs. 0. 2 million for 10 000 tonnes. The net benefit of Rs. 0. 2 million (Rs. 0. 4 - 0. 2 million) would be about 7. 5% of the average value of the produce irradiated. Even at the end of the season when Khariff prices are at their lowest (between mid-February and early March) traders would derive a net benefit of 3. 5% to 4% of the value of produce as a result of irradiation.

4. 10. Shipment losses in Khariff exports

Lasalgaon exports about 25 000 tonnes of Khariff onions to the Gulf countries, Ceylon and Southeast Asia by sea. Traders report that losses in these consignments are high and resultant problems in the smooth flow of trade occur frequently. Reduction in shipment losses by irradiation of Khariff onions may therefore enhance the exports to these countries and extend the trade to others.

4. 11. Storage prospects of Rabi onions

The price fluctuations in various centres (Fig. 4) indicate that it may be profitable for farmers and traders to store Rabi onions, which arrive in the primary produce assembling markets such as Lasalgaon between April and June, and sell them in the months between July and October when prices escalate. Figure 3, showing the relationship between arrivals and prices ONIONS IN INDIA 101 in Lasalgaon, indicates that substantial quantities of fresh Rabi arrivals between April and June could be stored up to three months to fetch higher prices between July and September4. A study of arrivals and despatches at Lasalgaon showed that the maximum quantity of produce kept in storage is from arrivals in April and May [ 8]. Nearly 3000 tonnes of arrivals in each of these months, comprising 30% of arrivals in April and 35% of arrivals in May, are kept for storage up to a maximum of three months and progressively released in June, July and August when prices are high. The average storage period is about two m on th s. Though traders and farmers reported that storage losses in Rabi onions on account of sprouting, rotting and dehydration were high, their estimates varied considerably and no proper records of storage losses were available.

4. 12. Monetary benefits of reducing storage losses in Rabi onions by irradiation

The results of the field trial on Rabi onions discussed earlier showed that savings in total losses as a result of irradiation may be 6, 18 and 20% for 2, 3 and 4 months' storage respectively. The trial also indicated that irradiated and unirradiated onions may be stored in chawls for not more than 4 and 3 months respectively, as storage beyond these periods may impair their marketability. It may be emphasised that these are the results of a single trial with a limited quantity of Rabi onions and confirmation by com m ercial-scale storage trials using 40-50 tonnes of onions may be required. However, the results of the experiment indicate that irradiation may benefit farmers and village traders, who normally store Rabi onions for periods up to three months, to extend the storage period up to a maximum of four months and fetch better prices during the off-season. Despite the limitations of the experimental data, it was essential to make an effort to quantify the monetary benefits to farmers and village traders of post-harvest storage of Rabi onions with and without irradiation and thereby estimate the quantity of Rabi produce that could be irradiated in Lasalgaon. For this purpose an attempt was made to deduce the optimal storage and marketing strategy for both irradiated onions and unirradiated onions and quantify the incremental benefits, if any, to farmers and traders if they irradiated their Rabi produce. In this analysis the average monthly price fluctuations in the Lasalgaon market (Fig. 3) and the results of the storage trial with Rabi onions (Table I) were used. The maximum storage periods for irradiated and un­ irradiated onions were taken as three months and four months respectively, as indicated by the Rabi storage trial. The cost of irradiation was assumed as Rs. 20/- per tonne (to be discussed later) and the cost of storage, Rs. 15/- per tonne for 1-2 months and Rs* 20/- per tonne for 3-4 months, these being the approximate rates in Lasalgaon.

4 The slight fall in price in September at the Lasalgaon market is against the All-India trend of continuously rising prices between May to October (F ig.4). It can be seen from Fig.3 that the market prices

in September relate to an extremely small quantity of produce stored for over three months. The marketability of the produce may have been very poor, as suggested by the field storage trial. This assessment was supported

by traders who said that if onions of marketable quality were available in September, they could obtain much higher prices than in August. The price of marketable produce in September is, therefore, taken as the average

of August and October prices, i.e . Rs. 3 3 0 /- per tonne, for the subsequent analysis. 102 SUDARSAN

The computational method may be illustrated by means of the following e x a m p les:

A. One tonne of fresh market arrivals in May are irradiated, stored for 2 months and sold in July

(1) Market price per tonne in May R s. 135/ - (2) Losses during storage period 10% (3) Quantity sold in July 0. 9 t (4) Market price per tonne in July R s . 220/- (5) Revenue in July [ (4) x (3) ] R s . 1 9 8 / - (6) Total cost of irradiation and post­ irradiation storage for two months R s . 3 5 / - '(7) Net income in July [ (5) - (6)] R s . 16 3/ - (8) Net benefit of irradiation and storage [ (7) - (1)] R s . 28/ -

The arrivals in May could be stored up to September (4 months) after irradiation. Hence they could be sold in May itself, June, July, August or September. The corresponding net benefits for sale during each of the above months could be arrived at, as shown in the above example. The results would show that the net benefits of sale during May, June, July, August and September are 0, -27, +28, +33, +53 rupees respectively. Hence the optimal strategy for May arrivals that are irradiated would be to store them for 4 months and sell during September for a net benefit of Rs. 53/-.

B. One tonne of fresh market arrivals in May are stored without irradiation for 2 months and sold in July

(1) Market price per tonne in May R s . 135/ - (2) Losses during storage period 16% (3) Quantity sold in July 0. 84‘ t (4) Market price per tonne in July R s . 2 20/- (5) Revenue in July [ (4) x (3) ] R s . 1 8 5 /- (6) Total cost of storage for 2 months R s . 15/ - (7) Net income in July [ (5) - (6) ] R s . 170/ - (8) Net benefit of storage [(7) - (1)] R s. 3 5 /- Fresh arrivals in May could be stored without irradiation up to August (3 months). The corresponding net benefits of sale during May, June, July and August are 0, -12, +35 and +8 rupees respectively. Accordingly, the optimal strategy for May arrivals that are not irradiated would be to store them for 2 months and sell during July for a net benefit of Rs. 35/-.

A comparison of A and В shows that the maximum monetary returns to farmers or traders who irradiate and store fresh arrivals in May would be higher than the maximum monetary returns for those who do not irradiate the produce and the incremental monetary returns for farmers and traders who irradiate their onions may be around Rs. 18/- per tonne, or approximately 13% of the initial value of the produce. It can be seen that the greater returns accrue from the reduction in storage losses and extension of the period of marketability by irradiation. The same analysis for fresh Rabi arrivals in April showed that the irradiated produce could be stored for four months for optimal sale in August. The net monetary benefits would then be about Rs. 17/- per tonne of initial ONIONS IN INDIA 103 quantity. It was found that unirradiated onions should be sold in April itself since the monetary benefits of storage without irradiation are negative for storage up to July (3 months). Thus the incremental monetary benefits of irradiating April arrivals and following the suggested strategy for storage and sale would be Rs. 17/- per tonne of initial weight or about 14% of the original value of the commodity. In the case of June arrivals farmers and traders who irradiate the produce should store for about four months to derive substantial monetary benefits in early October when the price is at its highest (Rs. 405/- per tonne). The net monetary benefits would then be around Rs. 90/- per tonne or about 60% of the original value. Farmers and traders who do not wish to irradiate the produce should sell in August (after two months' storage) for net benefits of about Rs. 59/- per tonne or nearly 39% of the value of the commodity in June. Thus the optimal strategy for irradiation and storage would yield 21% higher monetary returns than the optimal strategy for storage without irradiation. The optimal strategies for storage and sale of Rabi onions and the incremental benefits of irradiation are summarized in Table IV. The above computations are purposely simplified in order to indicate the potential benefits of irradiating Rabi onions. Their limitations are: (i) Price fluctuations within each month in a certain year and for the same month from year to year are masked by the usage of average monthly prices over 4 years (October 1967 to September 1971). (ii) There may be changes in the pattern of price fluctuations due to unforeseen reasons. However, a study of weekly average price fluctuations in the Lasalgaon market from October 1967 to September 197.1 showed that major deviations from the pattern shown in Fig. 3 may not occur. Average monthly arrivals in April, May and June are 7500, 6150 and 1500 tonnes respectively in Lasalgaon. It can be shown that if this entire quantity were to be irradiated, the total profit to farm ers and traders during the Rabi season could be higher by about Rs. 290 000 than the maximum profit without irradiation. This figure does not include the increased profits that the village traders would make in their transactions with the traders at the consumption centres. A strong incentive would therefore exist for irradiating the maximum quantity of Rabi arrivals that may be feasible to process in an onion irradiator at Lasalgaon.

4. 13. Estimation of demand for irradiation

An attempt was made to estimate the likely demand on an irradiator located at Lasalgaon, based on the analyses of the benefits of irradiating Khariff and Rabi produce, and from the data of monthly arrivals in the market (Fig.. 3). Table V shows the results of the demand analysis under different situations. The demand for consumption within the country in the first few years is expected to be about 22 000 tonnes (12 500 t from Khariff and 9500 t from Rabi arrivals against the annual arrivals of 58 000 t and 16 000 t, respectively during these seasons). The monthly break-down of this demand is also shown in Table V. In later years the internal demand may rise to a maximum of about 26 000 tonnes (15 000 and 11 000 t of Khariff and Rabi produce respec­ tively). The average demand for internal consumption would therefore be about 24 000 t/ a. 104 SUDARSAN

TABLE IV. SUGGESTED STRATEGY FOR STORAGE AND SALE OF FRESH RABI ARRIVALS WITH AND WITHOUT IRRADIATION AND THE INCREMENTAL BENEFITS TO FARMERS AND TRADERS WHO ADOPT IRRADIATION

1. Month of fresh arrivals A p r il M a y June

2. Annual market price (Rs./t) 1 2 7 1 35 1 5 0

3. Recommended month of sale A u g u st S e p te m b e r O c to b er

if irradiated

4. Net monetary benefits of 17 53 9 0

irradiation and storage (R s./t)

5. Recommended month of sale A p r il July A u g u st if not irradiated

6. Net monetary benefits of -- 3 5 59 storage without irradiation (Rs. A )

7. Incremental monetary 17 18 3 1 benefits of irradiation and storage (Rs. /t)

8. Incremental monetary 14°/o 1 3 % 2 1 % benefits of irradiation and storage as a % o f initial value of the

commodity stored

TABLE V. POTENTIAL DEMAND FOR ONION IRRADIATION IN LASALGAON (in tonnes)

Estimates of Khar iff Rabi T o t a l potential demand season season

A r r iv a ls 5 8 5 0 0 16 0 0 0 7 4 5 0 0

Expected demand

in the initial 1 2 5 0 0 9 5 0 0 2 2 0 0 0 years, excluding exp orts

Monthly break-down O c to b er 1 0 0 0 A p r il 4 0 0 0 of above demand (Second half)

N o v e m b e r 2 5 0 0 M a y 4 0 0 0

D e c e m b e r 2 5 0 0 June 1 5 0 0 (F irst h a lf ) January 2 5 0 0

February 2 5 0 0

M a rc h 1 5 0 0

Potential demand

in later years, 1 5 0 0 0 1 1 0 0 0 2 6 0 0 0 excluding exports

Maximum potential

demand, including 3 0 0 0 0 1 5 0 0 0 4 5 0 0 0 ex p o rts ONIONS IN INDIA 105

The Khariff demand is expected to be mainly confined to the entire quantity of produce required for transportation to the Northeastern region. At present about 10 000 tonnes of Khariff onions are despatched by rail to consumption centres in Assam in this region. Reduction in transit losses by irradiation may enable Lasalgaon to despatch 2 5% more in the initial years and 50% more in the later years of irradiator operation. An average of 14 000 t of Khariff produce may therefore be expected to be irradiated annually for consumption within the country. At present about 6000 t of Rabi produce are stored without irradiation for periods up to three months in Lasalgaon. Reduction of storage losses by irradiation and the anticipated monetary benefits may enable about 9500 and 11 000 t to be irradiated and stored in the initial and later years of operation. An average of about 10 000 t of Rabi produce may therefore be expected to be irradiated annually at Lasalgaon for internal consumption. About 25 000 t of Khariff and 5000 t of Rabi produce are exported annually from Lasalgaon. As export of irradiated produce must await clearance from the health regulatory authorities in importing countries and the time required to obtain these clearances could not be estimated, these quantities were not included in the above demand estimates. Preliminary estimates indicate that 15 000 t of Khariff and 4000 t of Rabi exports may benefit from radiation treatment. Inclusion of these quantities may increase the average potential demand for irradiation capacity at Lasalgaon to about 43 000 t. This would represent an increase of 80% over the average potential demand for internal consumption. The main limitation of the above demand analysis is the exclusion of arrivals that may be diverted from other assembling markets to an irradiator in Lasalgaon. Though the likely diversions may be significant, they were difficult to estimate. In addition, it may be desirable to minimize them, if possible, for reasons discussed later.

4. 14. Irradiator type and technical specifications

Techno-economic considerations, including the existence of the capability in India, to produce megacurie quantities of cobalt-60 and indigenously fabricate large cobalt-60 radiation sources would lead to the preference for an irradiator with a cobalt source. The large volume of produce to be handled and the need to irradiate within a short period after harvest would necessitate a continuous irradiator at Lasalgaon. The produce should preferably be irradiated in bulk, without packaging, in the product boxes of the irradiator [ 8]. For onions a minimum dose of 6 krad [ 7] with an overdose (max/min) ra tio o f 2 [ 11] was specified and a source utilization efficiency of nearly 20% was considered feasible. For a capacity of 10 t/h the above specifications may necessitate a source strength of about 100 000 curies of cobalt-60, including an initial provision for decay during the year. A preliminary design for a com m ercial-scale onion/potato irradiator has been prepared in India [11].

4. 15. Choice of irradiator capacity

The choice of the throughput (t/h) for a future irradiator in Lasalgaon was mainly based on (i) the need to handle economically the maximum potential demand for irradiating onions meant for internal consumption and 106 SUDARSAN

a substantial portion of the likely export demand; and (ii) the need to irradiate the produce preferably within 14 days after harvest and curing [ 3] and there­ fore to provide for peak loads arising from fluctuations in arrivals within individual months5 . A preliminary comparison of three throughput rates, 5, 10 and 15 t/h, showed that a 5 t/h irradiator would not be sufficient to process even the average internal demand during April and May and the peak loads that may be expected within the months of November to February. On the other hand, a 15 t/h irradiator would be underutilized to the extent of about 40% during the period of continuous fresh arrivals (mid-October to mid-June), even if the maximum estimated demand including exports were to be realized. A 10 t/h irradiator would be able to process the maximum potential demand for internal consumption, with peak-load capability. If onions meant for export were also to be irradiated, the 10 t/h irradiator could theoreti­ cally handle the enhanced demand, but at the cost of peàk-load capability between November to February, April and May. Utilization of capacity during an estimated period of 8 months of continuous operation would be about 50%, considering only the potential demand for internal consumption and 90% including exports. From the above considerations a 10 t/h capability was recommended for a future irradiator in Lasalgaon [ 8]. During the period of four months when fresh onion arrivals do not occur it may not be possible to obtain significant quantities of suitable alternative agricultural commodities, such as potatoes, in Lasalgaon and the irradiator may remain largely idle.

4. 16. Preliminary cost-benefit analysis

The investment in a 10 t/h irradiator facility with the specifications mentioned is estimated from a study of various reports [9, 11, 12] to be approximately Rs. 2 million under Indian conditions, including cost of source installed. The annual operating costs, excluding interest and depreciation but including source replenishment, would be approximately Rs. 0.2 million. The economic life of the plant and project is estimated to be about 15 years. The future irradiator in Lasalgaon may be operated (i) as part of a fully integrated business venture engaged in purchase, radiation processing and sale of onions; or (ii) as a service facility to farmers and traders. In case (i) above the entrepreneur may invest Rs. 2 million in the irradiator, hire storage facilities for long-term storage of Rabi onions and sell irradiated Rabi and Khariff produce to village traders in Lasalgaon itself. The average demand, excluding the likely demand for exports of irradiated onions, was shown to be 24 000 t. From the analyses of benefits of irradiating Khariff and Rabi produce it can be shown that the extra revenue of radiation processing and sale of these onions may be about Rs. 0. 8 to 0. 9 million against an annual operating cost of Rs. 0. 2 million. The annual monetary returns would, therefore, be about Rs. 0. 6 to Rs. 0. 7 million. With these returns it can be shown that the internal rate of return (IRR )6 of the project would be over 30%, indicating that a future onion irradiator at Lasalgaon may

5 Between December and February weekly arrivals of over 3000 t have been frequently recorded in L a s a lg a o n .

6 The IRR is a measure of the profitability of an investment and is defined as the discount rate that equalizes the present values of the cash inflows and outflows over the project life. ONIONS IN INDIA 107 be a sufficiently profitable investment. The profitability would be higher if instead of selling the irradiated onions in Lasalgaon itself, the management trades directly with city traders at consumption centres. The profitability would further increase in case the average potential demand including exports (43 000 t) is realized. Alternative (ii) would be a service facility charging farmers and traders a fixed rate per tonne of produce irradiated. Discussions with farmers and traders in Lasalgaon indicated'that if farmers were to benefit directly from the project, the choice of the irradiation charge must take into account not m erely the anticipated monetary returns, but also the ability of farmers to pay the amount. From these considerations, an irradiation charge of Rs. 20 per tonne was determined as the feasible rate that may enable the estimated potential demand to be fulfilled. With this charge the IRR's of a service facility for the two demand estimates of 24 000 t (average demand excluding exports) and 43 000 t (average demand including exports) would be approximately 9 and 30% respectively, indicating that the profitability of a service facility would be moderate, but can be improved substantially if irradiated onions are exported. The benefits to the economy as a whole would obviously be higher than the IRR's of a service facility and should include the higher earnings by farmers and traders and the probable benefits to consumers as a result of irradiáting onions. The IRR of an integrated venture (over 30%) incorporates the monetary benefits of reducing storage and transportation losses and is, therefore, a better measure of the returns to the economy.

4. 17. Socio-econom ic factors affecting economic feasibility

A majority of the onion farmers in Nasik District are small farmers with holdings of less than half a hectare. Onion production is their main source of income. The average yield is only about 12 and 16 t/ha for the Khariff and Rabi crops respectively, and as onion is a low value commodity, the annual incomes of most onion farmers is extremely low (less than Rs. 3000). Their poor financial position, especially after incurring the costs of produc­ tion between sowing and harvest and meeting their household expenses during this period, generally prevents them from storing Rabi onions in the expec­ tation of better prices. This leads to large market arrivals immediately after the Rabi harvest and low prices fetched by farm ers. In certain years distress sales are observed in April and May. The farm er cannot obtain institutional finance in the form of bank loans against the value of his produce since banks are not willing to give loans against semi-perishable commodities, especially onions, whose prices fluctuate widely. The local farm ers' co-operative may not be strong enough to alleviate these traditional economic difficulties of its members.

4. 18. Infrastructural support required by farmers

It is apparent that if farm ers are to benefit directly and substantially from the project, it may have to be operated as a service facility and, in addition, the following infrastructural facilities must be strengthened or p rom oted : (a) Provision of long-term storage facilities to farmers for their Rabi produce 108 SUDARSAN

(b) Extension of credit facilities to farmers to cover at least a part of the value of produce stored and the direct costs of irradiation and long term-storage (c) Strengthening of the local farm ers' co-operative. Agricultural banks and other financial institutions may extend credit against storage of produce with improved storage characteristics, as can be demonstrated in the case of irradiated onions. If the above steps are taken, a substantial portion of the produce that could benefit from irradiation may be routed through the farm ers' co­ operative instead of being sold to the village traders. Figure 2 shows the present distribution system for onions where the role of the farm ers' co­ operative is not very significant. An active farm ers' co-operative would also provide an institutional framework for centralizing the following activities: (i) Procurement of produce from members and sale of irradiated onions on their behalf (ii) Cartage from assembling yard to irradiator and from irradiator to long-term storage (iii) Payment of irradiation charges (iv) Management of postirradiation storage facilities (v) Control of credit to farmers in co-operation with the lending institutions. Figure 5, showing the distribution system that may be required for irradiated onions, indicates the necessary centralization of pre- and post­ irradiation activities through the farm ers' co-operative to benefit farmers directly. Centralization of these activities under the control of a strengthened farm ers' co-operative would also benefit the management of a service irradiator, whose expertise and competence may be largely technical and operational in nature. Village traders would benefit directly from the project as they are not constrained by financial difficulties, they can easily afford the extra costs of irradiation and storage, and they possess high risk-taking ability. There­ fore if the irradiator were to be operated as a service facility, without the recommended infrastructural build-up, the main customers and beneficiaries would be the wholesale traders and big agriculturalists who normally function as traders as well. The majority of the farmers would only derive indirect benefits, as increased competition amongst traders for a commodity with enhanced storage ability may increase to some extent the prices paid to them.

4. 19. Commercial factors affecting economic feasibility

In India onions figure in the lowest price category among vegetables. They generally retail at a price that is about 50% less than that of potatoes. It is unlikely that consumers would pay a significantly higher price for irradiated onions since only quantities required for limited periods are stored at households and significant losses are not encountered. However, between mid-August and mid-October when fresh onions are not available, the irradiated produce may enjoy a slight consumer preference as a result of better appearance (Rabi storage trial). Retailers may be able to induce and establish a greater preference during this period by active promotion, provided the price difference is not significant. City traders, ONIONS IN INDIA 109

HARVEST I PRODUCER'S STORAGE

SALE TO FARMERS* PRODUCE ASSEMBLING CO-OPERATIVE MARKET

SALE TO PRIMARY TRADERS

IRRADIATOR NEAR PRODUCE ASSEMBLING MARKET

POST-IRRADIATION STORAGE AT STORAGE FACILITIES OF THE FARMERS CO-OPERATIVE 4 TRADERS' STORAGES

SALE TO TRADERS IN MAJOR DISTRIBUTION AND CONSUMPTION CENTRES

TRADERS’ TEMPORARY STORAGES IN ABOVE CENTRES i WHOLESALERS (CITY MARKET) 1 RETAILERS

CONSUMER

FIG.5. Distribution flowchart for onion irradiation.

who store the produce in large quantities for periods up to one month may distinctly prefer irradiated onions and may pay a higher price corresponding to. the reduction in losses during storage with them. At present onions are retailed loose and it is unlikely that consumers would absorb the higher cost as a result of packaging if irradiated onions are required to be sold in sealed and properly labelled consumer packs. Differen­ tiation between irradiated and unirradiated onions may, therefore, be possible only up to the level of retailers who may store the irradiated onions in jute bags or boxes with the required notation or label.

4.20. Impact of an onion irradiator in Lasalgaon

The economies of Lasalgaon, Pimpalgaon and several other villages in Nasik District, particularly in Niphad Taluka, depend to a large extent on onion production and marketing. It is obvious, therefore, that an irradiator processing at least 22 000 t, or about 30%, of the annual onion arrivals would have a major socio-econom ic impact on Lasalgaon and the onion production and marketing centres around it. n o SUDARSAN

The availability of a method for reducing storage losses and thus protecting agricultural incomes may cause onion production in the area to become more profitable than at present. As a result production of onions in the area supplying them at present to Lasalgaon may increase. As irradiation would improve the viability of long-term storage and long­ distance transport, farmers may obtain somewhat better prices from traders during the months of large-scale arrivals when prices are generally low. However, the pattern of price fluctuations in Lasalgaon is expected to remain essentially the same. This is because the quantity irradiated would be only about 1. 5 to 3% of the national onion production, and prices in Lasalgaon are more a function of the rate of arrivals and price fluctuations throughout the country than in Lasalgaon alone. However, if the total potential for onion irradiation in the country, which may be about 10% of the annual production, is fulfilled, "there could be a moderating effect on price fluctuations through­ out the country, benefitting consumers and small farm ers. Onions arriving in Lasalgaon are mostly produced within a 50 km radius from Lasalgaon. Within this area there are several village assembling markets and the rate of arrivals in each market depends on its nearness to the producer and on small differences in the prices prevailing in each market. An irradiator in Lasalgaon may attract a portion of the arrivals that are normally traded in the other markets. This may disturb traditional trade patterns and dislocate some village traders and workers whose livelihood depends on the onion trade in these centres, perhaps creating socio-econom ic problems. A desirable approach may, therefore, be to reduce the likely diversions of produce from other markets by suitably limiting the capacity of an irradiator in Lasalgaon and exploring the economic feasibility of onion irradiation in other prominent neighbouring markets such as Pimpalgaon.

5. RELEVANCE TO RADIATION PRESERVATION OF AGRICULTURAL COMMODITIES IN DEVELOPING COUNTRIES

The foregoing is an attempt to delineate various factors influencing the economic feasibility of onion irradiation in India, with special reference to a promising location. The relative emphasis on each of these factors may vary considerably, depending on the commodity, the country and the purpose of irradiation. However, in many developing countries, particularly those in the tropical regions, the conditions and practices relating to harvest, storage, transportation and commerce are similar and the socio-econom ic problems described earlier may be equally relevant. These factors are applicable to a large extent to other agricultural commodities, particularly semi-perishables like potatoes. As in the case of onion irradiation in Lasalgaon, considerable economic potential and need may exist for the radiation preservation of onions, potatoes and other agricultural commodities in specific locations in many countries, particularly in developing countries. Detailed feasibility studies need to be carried out and widely publicized to demonstrate this need and potential so as to bring food irradiation technology closer to widespread practical application. Developing countries, whose greater need for food irradiation has been extensively discussed, must increase the level and scale of research in the laboratory, trials in the field and tests in the market for each promising commodity and location. ONIONS IN INDIA 111

The subsequent, and more important, efforts required are to test for consumer acceptability, to educate and inform the trade and the public, to obtain the acceptance and support of the health regulatory authorities, and to generate interest and commitment in the industry. These efforts would call for a major allocation of scarce financial and physical resources, and skilled scientific workers, technologists, market research and financial analysts, psychologists, sociologists and managers. Developing countries generally cannot marshal these resources speedily and independently. A detailed wholesomeness study alone is estimated to cost about $ 250 000 for each commodity [ 13]. Till now it is understood that only two such studies have been carried out in a single developing country (India), and only one developing country (Thailand) has obtained health clearance for a single agricultural commodity (onions). . The high cost of research and development in food irradiation, the scarcity of facilities and skilled specialists and the sim ilarities in conditions, - practices and problems would argue for closer collaboration with a view to sharing expertise and costs among developing countries. Such collaborative efforts among groups of countries with common features are required in addition to the existing and proposed co-operation in food irradiation on an international level. The suggested collaboration among developing countries could span the scientific aspects including wholesomeness testing, and the technological, techno-economic, and commercial aspects of introducing irradiated foods in these countries. Joint efforts in these areas may yield considerable mutual benefits. As an example, the feasibility of exporting Nasik onions irradiated at a future facility in Lasalgaon is dependent on clearances for onions in India and the importing countries, which are all developing countries. A joint effort to obtain clearance in these countries would greatly enhance the economic viability of the proposed irradiator and at the same time improve and extend the trade in this commodity to the mutual benefit of all the countries c o n ce rn e d .

6. SUMMARY AND CONCLUSIONS

Despite onion being a low-value item, there is considerable economic potential in India for irradiation as a means to reduce storage and transporta­ tion losses and to extend the marketing period. A detailed analysis of the prospects of onion irradiation in a promising location showed that it may be feasible to irradiate fresh onions continuously for about eight consecutive months, and an irradiation facility may be a sufficiently profitable investment. The profitability of the investment could be significantly enhanced if exports of irradiated onions are permitted. An onion irradiator could be operated either as part of an integrated business venture or as a service facility, depending on the objectiveness of the management. If a majority of farmers are to benefit directly from the project, it should preferably be operated as a service irradiator and, in addition, various infrastructural facilities need to be strengthened or provided. Onions, being a low-value commodity, are retailed only in the loose form in India. Therefore, additional costs such as costs of consumer packaging, if required to be incurred to differentiate irradiated produce, would be an unfavourable factor in practical feasibility. 112 SUDARSAN

The various considerations pertaining to the techno-economic feasibility of an onion irradiator in India may be of particular relevance to the radiation preservation of semi-perishable commodities in other developing countries. The similar needs, problems, conditions and practices within groups of countries such as developing countries would call for closer collaboration among them in addition to international co-operation, for deriving the benefits of food irradiation. Such collaboration would be also required in view of the greater common need for food irradiation, the high costs of research and development and limitations in the requisite facilities and expertise in developing countries.

ACKNOWLEDGEMENTS

I acknowledge with gratitude the guidance by way of comments and suggestions and the support of organizational facilities received from scientists and administrators involved in the food irradiation programme at the Bhabha Atomic Research Centre (BARC), Trombay; officials of the Department of Atomic Energy, Bombay; my colleagues in the Programme Analysis Group; and Dr. Y.A. Kamath, Head, Library and Information Services, BARC.

REFERENCES

[1] LEWIS, N .F ., MATHUR, P. B ., Extension of storage lives of potatoes and onions by cobalt-60 rays, Int.

J. Appl. Radiat. Isotopes 14 (1963) 443.

[2] DHARKAR, S .D ., "Report on BARC Programmes in food irradiation.- status of project on preservation of

potatoes and onions by sprout inhibition", Food Irradiation (Proc. Seminar Trombay, 1969), Bhabha Atomic

Research Centre (1969) 24.

[3] NAIR, P.M ., THOMAS, P., USSUF, K. K. , SURENDRANATHAN. K .K ., LIMAYE, S.P .. SRIRANGARAJAN, A .N ., PADWAL DESAI, S .R ., "Studies of sprout inhibition of onions and potatoes and delayed ripening of bananas and mangoes by gamma irradiation", Radiation Preservation of Food (Proc. Symposium Bombay,

1972), IAEA, Vienna (1973) 347. [ 4 ] Unpublished BARC data. [6] Unpublished BARC data.

[6] KARNIK, K .S ., Radiation Preservation of Onions and Potatoes in India - a Macro Study, Department of

Atomic Energy, Bombay, 1969, unpublished. [7] JOGLEKAR, P .N ., Micro-study of Nasik District for Onion Irradiation, Department of Atomic Energy,

Bombay, 1970, unpublished.

[8] SUDARSAN, P ., THOMAS, P. , AGARWAL, N .K . , Economic Feasibility of an Onion Irradiator in Lasalgaon,

Department of Atomic Energy, Bombay, 1972, unpublished*

С9] COHEN, Y ., Economic Feasibility of the Use of Large Radiation Sources for the Preservation of Potatoes and Onions(1966) (.Original in Hebrew, translation by US Army Natick Laboratories),

[10] INDIAN INSTITUTE OF FOREIGN TRADE, Survey of India’ s Export Potential of Fresh and Processed Fruits

and Vegetables 2 ( 1968) 100.

[11] KRISHNAMURTHY, K ., IYA, V. K ., A Study Report on 'GIPSI' (Gamma Irradiation Plant for Sprout

Inhibition), BARC, Bombay, 1970, unpublished.

[12] BRYNJOLFSSON, A ., "Factors influencing economic evaluation of irradiation processing", Factors Influencing the Economical Application of Food Irradiation (Proc. Panel Vienna, 1971), IAEA, Vienna

( 1 9 7 3 ) 1 3 .

[13] GORESLINE, H .E ., "Status and perspectives of food irradiation", Radiation Preservation of Food (proc. Symposium Bombay, 1972), IAEA, Vienna (1973) 1. BACKGROUND TO THE ESTABLISHMENT OF THE FIRST FOOD IRRADIATION PLANT IN JAPAN

K . U M E D A National Food Research Institute, Koto-ku, Shiohama-1, Tokyo, Japan

Abstract

BACKGROUND TO THE ESTABLISHMENT OF THE FIRST FOOD IRRADIATION PLANT IN JAPAN.

In 1973 a com mercial potato irradiator was established at the Shihoro Agricultural Co-operative Association in Hokkaido, Japan, with a capacity of about 10 000 tons of potatoes per month. The я Со source, which is approximately 300 kCi, is situated at the centre of a circular conveyor system, 5 m in radius, on which the potato containers are loaded. Details of the facility are given. Its establishment was facilitated by the following 1 m ain factors: (1) sprout inhibition of potatoes by irradiation fitted well into the proposed new Japanese sy stem for the distribution of fresh agricultural produce; (2) the establishment of a research group to collect all the necessary data ; (3) general consumers have recognized the safety of irradiation treatment, especially in view of the present problems of chem ical residues in agricultural products and foods in Japan; and (4) the Agricultural

Co-operative Association, which was in charge of the plant organization, had a great deal of technical expertise, thus understanding the implications of radiation treatment, and also aimed w ell-tim ed propaganda at the farmers.

INTRODUCTION

Food irradiation in Japan has had a late start compared with other countries, although research has been going on for almost 20 years. The first experiments were conducted on spoilage prevention in fish through the application of gamma rays at the Tokyo University of Fisheries. In 1967 a national project was started with governmental support to establish a com m ercial food-irradiation unit and this resulted in the world's largest food-irradiation plant at Hokkaido, in the northern part of Japan. This project is co-ordinated with the National Science Nuclear Research Programme and research is centralized by the Japanese Science and Tech­ nology Agency with the participation of national and public research institutes and universities. The first result of this National Programme has been that the application of gamma irradiation for sprout inhibition of potatoes was authorized in August 197 2. A com m ercial plant with a monthly capacity of irradiating 10 000 tons of potatoes was established in 1973 for this purpose. This will also be used for onion sprout inhibition. The National Programme also covers disinfestation of cereals, radurization of sausages and kamaboko and surface sterilization of oranges. Recent progress made in these projects and the present status of food irradiation in Japan can be found in the literature [1-3]. This report concen­ trates on the following points with special reference to potato and onions:

(1) Progress made in food irradiation in Japan (2) Problems encountered during the formulation of the project (3) First Japanese potato irradiator constructed in Shihoro (4) Status and background, which resulted in the establishment of the potato irradiator in Japan.

113 114 UMEDA

Atom ic Energy Commission I Atom ic Energy Bureau

Science and Technology Agency

Steering Committee on National Project on Food Irradiation Food Irradiation

R a d ia tio n e ffe c ts

National Food Research Institute (Agricultural products) *

Tokai Regional Fishery Research Laboratory (Seafoods)

National Institute of Anim al Industry (Anim al products)

Industrial Products Research Institute (Packaging materials)

Ministry of Wholesomeness Agriculture and Forestry National Institute of Hygienic Sciences

National Institute of Nutrition Ministry of

International Trade National Institute of Health

and Industry Radiation engineering

Ministry of Welfare Takasaki Radiation Chemistry Research Establishment of Japan Atom ic Energy Institute

Basic research

Institute of Physical and Chem ical Research

Association organizing members from universities, other

institutions and industries

F IG .l. Organization of the. National Research Programme on food irradiation.

1. PROGRESS MADE IN FOOD IRRADIATION IN JAPAN

In 1965 a special committee was formed under the auspices of the Japanese Atomic Energy Commission to draw up a programme for food irradiation research. The committee deliberated on the following points:

(a) The benefits of food irradiation to both producers and consumers, with a broad view of its impact on the national economy. (b) The feasibility of the project on a commercial scale, conducting basic, applied and development research, the resulting data to be made available to Japanese industry. (c) The commencement of food irradiation with the economically most important products.

Figure 1 shows the organization of the National Programme on Food Irradiation Research in Japan. JAPANESE FOOD IRRADIATION PLANT 115

A special feature of this National Food Irradiation Programme is the complete participation of all the concerned government ministries and the fact that it is centred around national and public research institutes and universities. As the consequence of numerous administrative problems, it was decided to begin research on the irradiation of potatoes and onions first and then to continue with products such as cereals, sausages, kamaboko and oranges. To ensure the smooth progress of this project, an administrative committee for food irradiation research was formed with the participation of national research institutes, universities and government ministries concerned. Many problems arose with regard to the use of available data. It was first necessary to decide to what extent foreign research data should be utilized to solve the problems in Japan. In addition, problems in com m ercial­ ization and aspects of source engineering had to be resolved. In view of the social impact of irradiated food at the stage of future practical use, it was decided to use foreign research data only as reference material and thus all the research work, including wholesomeness tests, was conducted in the country. The various recent crises in the field of food additives and new protein sources have shown that this decision was most appropriate. With regard to the problem of distribution and utilization, it was important to keep in mind both the producers and consumers and, since they lack techniques, that only the government could undertake the necessary research. Thus the decision of the committee proved to be in accordance with what was in fact required. Table I shows the present progress of the National Programme on Food Irradiation.

TABLE I. NATIONAL PROJECT OF FOOD IRRADIATION RESEARCH IN JAPAN (Jan. 1974)

R a d ia tio n W holesome ness Ite m s O b je c t e f f e c t test

Sprout F in ish ed F in ish ed Authorized 1972-08-30 in h ib itio n

O n ion Sprout F in ish ed F in ish ed P e titio n in h ib itio n will be presented soon

In sect Fin ish ed C o n tin u ed Basic studies of

c o n tr o l (1 9 7 4 ) radiation engineering - using sm all grain

W h e a t In sect F in ish ed C o n tin u ed irradiator have c o n tr o l ( 1 9 7 5 ) fin ish e d

Final report'on radiation S au sage S h e l f - l i f e F in ish ed C o n tin u ed effects will be e x te n sio n (1 9 7 0 ) presented soon

K a m a b o k o S h e l f - l i f e C o n tin u ed N o t y e t e x te n s io n ( 1 9 7 4 ) started

Satsuma orange S u rfa ce C o n tin u ed N o t y e t

pasteurization ( 1 9 7 6 ) started 116 UMEDA_

2. PROBLEMS ENCOUNTERED DURING THE FORMULATION OF THE PROJECT

2.1. Effects of irradiation on potatoes

2.1.1. Browning of irradiated potatoes

The irradiation of potatoes with more than 5 krad resulted in browning centred around the vascular bundle tissue. For example, when irradiated potatoes grown in the southern part of Japan were cut one week after irradiation about 10% exhibited browning, thus losing their food value. • The following was concluded with reference to the various potato-growing districts, their cultivation, maturity, storage conditions before and after irradiation. Browning was found to occur easily in immature, small potatoes of shorter cultivation period. To suppress this browning it was found neces­ sary to store longer after harvest'and before irradiation, and also to store at low temperature after irradiation [4]. Fortunately, the potatoes from the main potato-growing district, Hokkaido, did not show such browning.

2.1.2. Radiation effects on potatoes after the dormant period

Potatoes sprout after the dormant period and it is highly impractical to sort out these sprouted potatoes when irradiating. Experiments were conducted to see the effect of irradiation on these sprouted potatoes. It was found that the sprouts of potatoes that had just sprouted did not increase further after irradiation and easily fell off during storage. No further increase in spoilage percentage was observed, thus keeping a good market v alu e [5].

2.1.3. Radiation effects on curing damaged potatoes

From the results of basic research, irradiation delayed the curing of damaged potatoes. Experiments were conducted on sound tubers after the intentional infliction of damage like cuts, excisions and bruising. After irradiation the tubers retained their good quality without sprouting or extra rotting over long periods of storage [6].

2.1.4. Decrease in the sugar content of potatoes

When irradiated or non-irradiated potatoes were stored at low tempera­ ture for 4-5 days, the reducing sugar content was increased three to four times (Fig.2). When these potatoes are used for potato chips, pommes frites or shoe-strings, the browning reaction is accelerated and they thus lose their market value. When potatoes were kept at higher temperatures, their reducing sugar content was decreased (Fig.3), tests being made at 20°C for 10 days, at 25°C for 1 week and at 28°C for 4-5 days [6]. According to foreign reports, this effect is not observed with potatoes harvested and stored for over 7 months. Our experiments, however, show rapid decrease in reducing sugar even 10 months after harvest (Table II). Thus the irradiated potatoes could satisfactorily be used as good raw material for processing even after long periods [7 ]. JAPANESE FOOD IRRADIATION PLANT 1 1 7

Stored Time (Days)

FIG.2. Effect of irradiation on the reducing sugar content of potatoes stored at 5°C .

C o n t r o l

Time (Days) Time (Days)

Time (Days) Time (Days)

FIG .3. Effect of irradiation on the changes in reducing sugar content of May Queen potatoes stored at various temperatures. 1 1 8 UMEDA

TABLE II. REDUCING SUGAR CONTENT OF IRRADIATED POTATOES AT VARIOUS PERIODS (%)

Stored at Stored period in months Room temperature 5 ° С 5 е С -►room temperaturea

6 m onths Non-irradiated 0 . 3 2 0 . 7 0 ‘ 0 . 3 3

10 krad 0 . 3 3 0 . 7 5 0 . 3 1

8 m onths

Non-irradiated 0 . 1 6 0 . 7 2 0 . 2 6

10 krad 0 . 3 6 0 . 7 7 0 . 4 5

1 0 m onths Non-irradiated - 0 . 9 4 0 . 2 2

10 krad 0 . 3 5 0 . 9 8 ■ 0 . 3 7

a Samples were transferred from 5°C to ambient temperature at two weeks before analysis.

2.1.5. Shrinkage and deterioration of processing quality

Irradiated potatoes, even 7 months after harvest, when stored at ambient temperature keep good quality for domestic cooking and processing purposes. But 8 months after harvest shrinkage occurs due to water evaporation and the cell walls harden. This condition is acceptable for domestic purposes, but in the course of processing results in half-finished products. It is ' impracticable to adjust the processing lines to suit these individual variations and thus processing difficulties arise. Irradiated potatoes keep well at low- temperatures, and even if they are transferred to higher temperatures, until processing, maintaining their original good quality even after one year of storage [7].

2.2. Irradiation of onions

2.2.1. Dormant period of onions

For the first 2 years irradiation experiments on onions were a failure and it was even observed that onion sprouting increased after irradiation. These phenomena were not experienced here. The following conclusions were drawn‘with reference to variety and storage of onions before and after irradiation. It was thought that the dormant period of onions was 3 months after curing (i.e. submitting them to suitable temperatures and humidity). One month after harvest onions sprouted to lengths of about 1 -2 cm and irradi­ ation after this was not effective. It is difficult to establish the dormant period of onions from their external appearance. When the length of the inner bud is less than 2 cm it is said to be in the dormant condition. Onions harvested in Hokkaido were observed to have a dormant period of 30-40 days. At this dormant stage a dose of 3 krad inhibits sprouting completely [8, 9]. JAPANESE FOOD IRRADIATION PLANT 119

STORAGE BEFORE IRRADIATION (d)

FIG.4 . Deterioration of irradiated onions after storage for 8.5 months at room temperature [8] : (a) stored at

3°C before irradiation; (b) stored at room temperature before irradiation.

TIME FROM HARVEST (m onths)

FIG. 5. Effect of transference from 3 eC to room Temperature on undeteriorated onions — samples irradiated

26 days after harvest [8 ].

2.2.2. Extension of the dormant period

Since onions are dried for about 2 weeks after harvest, there is hardly any time to irradiate before the dormant period is over. After drying onions are stored below 5°C, which suppresses sprouting and the onions can be irradiated under these conditions. This could extend the dormant period for about 4 months (Fig.4). Fortunately, since the temperature is fairly low in Hokkaido, low-temperature storage could easily be carried out there [9]. 120 UMEDA

2.2.3. Inhibition of browning in the inner bud of onions

When onions are irradiated and stored at ambient temperature, the inner bud was observed to turn brown and die off. This does not cause a serious problem during domestic cooking as this part can be easily removed, but when processing into powder or flakes it gives a poor product. If irradiated onions are stored at low temperature, this inner-bud browning does not occur [10, 11]. If onions are stored at ambient temperature after irradiation, the keeping quality remains good even 7 months after harvest, regardless of inner-bud browning (Fig.5). After 7 months onions start shrinking and lose weight, resulting in poor market value. If they are to be kept for more than 7 months or to be pro­ cessed, postirradiation storage at low temperatures is advisable. After transferring the onions to ambient temperature, thus giving a period of about 1 month for distribution purposes, no browning, shrinkage or spoilage was observed and the original quality remained intact [10].

2.3. Wholesomeness tests '

Wholesomeness tests were conducted' on potatoes and onions with reference to poisons, cancer-form ing substances, induced radioactivity and destruction of nutrient substances. In addition, toxicity tests on animals

TABLE III. CRITERIA OF TOXICITY

1. Short- and long-term toxicity studies

General appearance

Body weight (Growth)

Food efficiency

M o r ta lity

Haematology (number of red and white blood cells,

haemoglobin, haematocrit, differential counts of white blood cells)

Biochemistry of blood (protein, albumin, glucose, cholesterol

urea-N, alkalinephosphatase, transaminase, GOT, GPT)

Organ weight

Gross pathology

Histopathology

2. Reproduction studies

Conception rate

Fœtal mortality

Litter size

T e r a t o lo g y

Growth of kits

Weaning rate

Pathology of animals of the third generation JAPANESE FOOD IRRADIATION PLANT 1 2 1

TABLE IV. TOXICITY TEST

A n im a l D u ration T ests G roups3 (m o n th .or

S p e c ie s Sex and number generation)

S h o r t-te r m M o n k e y сГ 2, $ 3 6 m P - 0 , P -6 0

L o n g -te r m M ou se 80 ( ç f 40, Ç40) X 5 2 1 m C, P-0, P-15

P - 3 0 , P -6 0

Long -t e r m Rat 60 (cf30.Ç30)x 5 2 4 m C, P-0, P-15

P - 3 0 , P -6 0

Reproduction and M ou se 41(0*18, Ç23)X3 4 g C, P-0, P-60 teratogenicity

3 C : Negative control; P-0 : Positive control; P-15, -30, and -60 indicate radiation doses in krad.

were also carried out. The criteria for the toxicity tests are shown in Tables III and IV. There was no indication of any toxicity in animals from p ota toes. With regard to onions certain problems were encountered and this resulted in delaying the research schedule. According to available foreign data, 25% dried onions (w/w) were included in animal feed, but at this level animals showed delayed weight increases, abnormalities in the weight of spleen and other internal organs and showed nervousness. Thus all experi­ ments were conducted with added dried onions forming less than 4% of the diet.

2.4. Source engineering

The general concept in planning an optimum-size container has been to consider its source efficiency and uniform absorbance of irradiated dose. It was decided to use at Hokkaido the wire-net container (inside dimensions: 100 cm (width) X 160 cm (length) X 130 cm (height), capacity 1.5 tons of potatoes), which had already been used for storage and road and rail distribu­ tion, in the irradiation plant, which was planned accordingly. From these containers potatoes are repacked into suitable small boxes (usually 20 kg) at wholesale centres in the suburbs of big cities and distributed to the retail market.

F I G .6 . General concept of S-type irradiator (Takasaki Rad.Chem .Est., 1973). 18200 ------:------1 12 0 0 C. ndow; ir aton conveyor; entance line; lne t er; t e; exi l . e n li it x e . H ; le b a t n r tu . G ; r fe s n a tr e lin . F ; e n i l e c n tra n e . E ; r o y e v n o c n tio ia d irra . D ; w o d in w . C ; l o o p 7. hor culur Co- ve Associ i at radi or pl A. source; water a w . B ; e c r u o s . A : ) w e i v e n la (p r to ia d irra to ta o p n tio ia c o s s A e iv t a r e p -o o C l ra ltu u ic r g A ro o ih h S . 7 . G I F

122 122 A D E M U FIG.8. Shihoro Agricultural Co-operative Association potato irradiator (section): A. source; B. water pool;

C. window; D. irradiation conveyor ; E. potato container; F. shield; G. irradiation chamber. 124 UMEDA

All experiments were conducted on a pilot-plant scale using these containers to obtain maximum and minimum absorbed doses of less than 15 krad and more than 6 krad (overdose ratio 2.5). The container had to be kept at least 4 metres away from the source [12]. The total weight of the container was 1.7 tons and for safe conveying various conveyor systems were considered. In the Hokkaido plant a circular conveyor system was installed for.econom ic reasons, though it ought to have been the 'S' shaped conveyor system, depicted in Fig.6.

3. THE FIRST JAPANESE POTATO IRRADIATOR AT SHIHORO

3.1. Establishment of the potato irradiator

The radiation plant established at Shihoro in Hokkaido has a 60Co source of 300 kCi and can irradiate about 350 tons of potato per day for a period of three months in a year, thus irradiating over 30 000 tons of potatoes per year. This plant costs a total sum of 389 million yen, of which 230 million yen were financed by the Japanese Ministry of Agriculture, 23 million yen by the Hokkaido Prefectural Government and the rest by the Shihoro Agricultural Co-operative Association. Figures 7 and 8 illustrate the plant. The wall is sealed with concrete, inside is the irradiation chamber and beside it are operational, experimental and analytical rooms.

FIG.9. Circular source frame and its arrangement. JAPANESE FOOD IRRADIATION PLANT 125

[ —,-ч"пг ML i*. *•

I f * 11™ r *, 4 “ - 4 ■ 1 ■У ■■

ИИ ¡•ШЁШШ4V ÜÏ.I», НИИ i t i * ¡ ш HR FIG. 10. Source unit.

In the diagram A is the cylindrical shaped source with a diameter of 1 metre, В is the water pool with a depth of 6.8 metres, С is the viewing window and D the conveyor, which can carry 19 containers. Potatoes to be irradiated are introduced in containers at E and pass through D, which circulates them for about an hour. They come out at F, and at G the containers do a round turn, passing back on to conveyor D, which circulates them for another hour, finally coming out at H to the warehouse. This system radiates about 10 containers in 1 h our. Figure 9 depicts the source frame with a diameter of 1 m and 36 source units. These 3 frames can be assembled toform the source. Figure 10 shows the source unit with 5 pencil-shaped 60Co rods, each of 7 500Ci, thus having 37 500 C i of 60Co. The assembled source-frame without the source unit is illustrated in Fig.11, while Fig.12 shows the conveyor from and to the warehouse. A complete view of irradiation chamber taken by a wide angle lense can be seen in Fig.13. In the centre is the source and at the far left is 126 UMEDA

FIG. 12. Conveyor entrance and exit lines. JAPANESE FOOD IRRADIATION PLANT 1 2 7

FIG.14. View of potato container. 1 2 8 UMEDA the window leading to the control room. In Fig.14 the potato container is shown on the round turntable, with a device to hold alternate containers with partly irradiated and non-irradiated potatoes entering the chamber. When the plant is operating at full capacity (3 months) the operational cost of the irradiated potatoes is estimated at 2000- 3000 yen per ton. If onions have to be irradiated in this plant, because of their lower dose require­ ment (half that of potatoes), the only adjustment needed is to double the conveyor speed. Because of the lesser bulk density of onions, there is more uniformity of the absorbed dose.

3.2. Merits of irradiation in distribution and utilization

We expect similar projects for onions and potatoes to be set up with government subsidy in the near future. At this stage I shall look into the merits of these projects. According to statistics collected in 1971, over half the total Japanese potato production of 3.2 million tons is grown in Hokkaido. Of this total production 1.3 million tons are used for starch manufacture, 260 000 tons for seed, 230 000 tons for feed and 47 0 000 tons for the farm ers' consumption, thus leaving only 800 000 tons for general distribution. Of these 800 000 tons over 27% are consumed in the two large cities of Tokyo and Osaka. The off-season for potatoes in Tokyo and Osaka is from late February to the end of May. If 6 0 000 tons are available in this 3-month off-season in Tokyo and Osaka, there need be no price fluctuation for potatoes. According to these statistics, if another plant sim ilar to that of Shihoro were available, there would be an ample supply of potatoes and thus no fluctuation in price. The Shihoro Agricultural Co-operative Association also plans to process potatoes. Of 250 000 tons annual yield 180 000 tons were used for starch manufacture and the rest marketed for general distribution. Last year a 2000 million yen potato-processing centre was established in Shihoro by the Agricultural Co-operative Association (Fig.15). This includes a 400million yen (US $1.3 million) potato irradiator. The potato snack plant (chips and shoe-strings) has a capacity of 60 tons per day with annual operation of 200 days. The frozen food plant (pommes frites and diced potatoes) has a capacity of 20 tons per day with an annual operation of 250 days. The capital investment for both these plants was 750 million yen. In addition, a warehouse for raw material storage with a capacity of 22 000 tons was built at a cost of 600 million yen and a store house for final-product storage at a cost of 150 million yen. The plant for waste­ water treatment cost 100 million yen. Out of the total 2000 million yen, over half was financed by the Ministry of Agriculture and Forestry and the Hokkaido Prefectural Government. In this processing centre 17 000 tons of potatoes could be handled each year. Non-irradiated potatoes would be used from September to January and 5000- 6000 tons of irradiated potatoes from January to April. With stored potatoes, if suitable for processing purposes and if economically feasible, the operation period could be extended to 10 months, the last 5 months of which would be supplied with irradiated potatoes. Up to now agricultural product processing and food processing have been difficult to carry out in parallel because of their short shelf-life and the short operational period. This problem is now solved for potatoes. With the increasing demand for irradiated potatoes by potato processors and also JAPANESE FOOD IRRADIATION PLANT 129

A: POTATO IRRADIATOR B: POTATO WAREHOUSE C:FRÇZEN FOOD PROCESSING D: FREEZER E: POTATO SNACK PROCESSING F: PRODUCTS WAREHOUSE G: OFFICE H: WATER TREATMENT

FIG. 15. Layout of Shihoro potato processing centre.

to stabilize market prices, at least two more plants of Shihoro type would seem to be necessary. These plants would profit the grower by producing processed foods and also be beneficial for the regulation of potato shipments to the market when the market price fluctuates. As mentioned before, the radiation treatment costs about 7 to 10 $/t, but the Shihoro Agricultural Co-operative Association intends to sell the irradiated potatoes at the same price as non-irrádiated potatoes since they can recoup the irradiation costs from the profits on processed foods. Thus the radiation plant benefits bot^ the producer and consumer. The annual crop of onions in Japan is 1.04 million tons per year. Of this 800 000 tons are for general distribution, 170 000 tons going to Tokyo. It has also been observed that the price fluctuation in the market is much greater than for potatoes. In addition onions sprout and spoil more easily than p ota toes. A practical way of distribution would have been to transport the 210 000 tons of onions produced in Hokkaido to big cities in the mainland to supplement the off-season demand. But due to the higher temperatures in Tokyo and 130 UMEDA other cities, the onions would easily sprout or spoil. Although they could be easily cold-stored in Hokkaido, where temperatures are low, in winter trans­ portation of these onions becomes a difficult task due to heavy snowfalls etc. Thus it can happen that when Tokyo is suffering from a lack of onions stored onions are being thrown away in Hokkaido. This results in Japan having to import 42 000 tons from countries like Taiwan and Australia at a cost of 2462 million yen as an emergency measure. The off-season demand (i.e. February to April) for onions in Tokyo and Osaka is about 7 0 000 tons. If onions were irradiated in Hokkaido and trans­ ported to warehouses in the suburbs of Tokyo and Osaka for distribution to the general market, two Shihoro-type plants would be adequate. As can be seen, the benefit of irradiation to the producers is very high, but it would be interesting to examine how much of these merits are acceptable to consumers. At present in Japan environmental pollution, abuse of food additives, residual agricultural chemicals and heavy metals in foods have become increasingly important problems. In addition, as the Japanese people were exposed to the atomic bomb during the war, there exists a certain fear of radioactivity among the people. Recently, as a result of various propaganda activities, people have begun to understand the usefulness of food irradiation, thus eliminating this fear. M oreover, wholesomeness tests of irradiated potatoes have been highly successful and consumers have become increasingly aware of their safety. For example, lectures on radiation treatment of foods and its wholesomeness are sometimes held to the dieticians and chefs who manage the food service division in big plants and enterprises and these meetings are usually held at the health centres located in every town and district. Through these meetings the propaganda for irradiated foods has been quite effective and smooth. The Tokyo Mass Food Service Co-operative Association has recently agreed to buy irradiated potatoes under a blanket co n tra ct.

4. STATUS AND BACKGROUND RESULTING IN THE ESTABLISHMENT OF THE POTATO IRRADIATOR IN JA.PANi

At present Japanese agricultural policy is in a transitional period and new policies for food processing and distribution are to be formulated. I should like to mention the policies and the background that resulted in the establishment of the potato-processing centre with irradiation unit already d is c u s s e d . There has been a lot of criticism of the Japanese agricultural policy because of its heavy Government subsidies, though this phenomenon is not- only peculiar to Japan but to all developed countries. This criticism was levelled because the government subsidy was used as a prop during difficult periods. Recently there has been heavy government subsidization of schemes like the potato-processing centre, frozen food manufacturing plants, juice manufacturing plants etc. These changes have been instrumental in establishing a completely new agricultural structure and a complex introduced by the Japanese Ministry of Agriculture and Forestry. This idea of agricultural complex is to increase the yield per unit of land, to encourage collective farming and to co-ordinate various individual agricultural units. These result in standardization of agricultural products, market expansion, efficient distribution and stability JAPANESE FOOD IRRADIATION PLANT 131 of the food supply and other prices. The promotion of this new idea includes the building up of food processing with proper and more efficient techniques. It is also necessary to increase the income of farmers by introducing new processed products. Furthermore, fresh agricultural produce should be evenly distributed and to prevent the increasing hazard of city environmental pollution the non-edible portions of agricultural produce should be left at the production site. It is also worth mentioning that setting up processing plants at the production sites helps to control the labour drain to major cities. The introduction of new techniques to the farmers will also result in graded commodities for the general consumer. The prevailing system of product distribution where middlemen come onto the scene at several stages and make huge profits results in poor incomes to the farmers and higher prices and unstable supplies to the consumer. Agricultural produce is generally highly perishable and, in processing it, simple processing techniques have to be adopted to maintain normal and acceptable flavours etc. Furthermore, if farmers themselves do the pro­ cessing, a lot of transportation problems can be solved since agricultural produce has usually a high water content. M oreover, considerations of pro­ duct distribution in the Japanese Archipelago are important. In the Japanese Archipelago the major agricultural producing areas of the future are located in the northern and southern parts to the major consuming areas, which range from Tokyo to Osaka. Thus the produce could be even partially pro­ cessed ¿.n the growing area and then brought to the suburbs of these conur­ bations for full processing before distribution to the consumer. ' With this new agricultural policy as a background, sprout inhibition of potatoes by irradiation''will become a part and parcel of this new policy. In the near future an\onion-irradiation plant will also be established and we expect to build a processing plant along '.with it to improve even distribution.

REFERENCES

[1] MATSUYAMA, A., "Present status of food irradiation research in Japan, FAO/IAEA Study Group Meeting on Food Irradiation for South-East and East. Asian Countries, 1 9 7 1 . [2] MATSUYAMA, A:. "Present status of food\irradiation research in Japan with special reference to microbiological and entomological aspects!1, Radiation Preservation of Food f Proc. Sym p., Bombay,

1972), IAEA, Vienna (1973) 261. . ^ [3] SATO, T ., Peaceful Uses of Atomic Energy (Proc.Conf. Geneva, 1971)12, ÎJN, New York, IAEA,

Vienna (1972) 325. v [4] TATSUMI, Y ., CHACHIN, K., MATSUZAKA, М ., OGATA, K ., J.Food Sci.Technol. japan 20

(1973) 132. [5] UMEDA, K ., TAKANO, H ., SATO, T ., J.Food Sci.Technol. Japan 16 (1969) 11.

[6] TAKANO, H ., AOKI, S., UMEDA, K ., SATO, T ., Rep.Nat.Food Res.Inst. (in press). [7] TAKANO, H., SUZUKI, T., UMEDA, K., J.Food Sci.Technol. Japan (in press). [8] CHACHIN. K., MATSUZAKA, М ., HONJYO, H., OGATA, K., J.Food Sci.Technol. Japan 2£

(1973) 158. [9] TAKANO, H ., UMEDA, K ., SATO, T ., Rep.Nat.Food Res.Inst, (in press).

[10] TAKANO, H ., AOKI, S., UMEDA. K ., SATO, T ., J.Food Sci.Technol. Japan (in press).

[11] CHACHIN, K ., OGATA, K .. J.Food Sci.Technol. Japan 18(1971) 378.

[12] KUME, T ., TACHIBANA, H ., AOKI, S., SATO, T ., J.Food Sci.Technol. Japan 20 (1973) 492.

COMMERCIALIZATION OF IRRADIATED POTATOES, MUSHROOMS, ONIONS AND SPICES IN THE NETHERLANDS

D . de ZEEUW Instituut voor Toepassing van Atomenergie in de Landbow, Wageningen, The Netherlands

Abstract '

COMMERCIALIZATION OF IRRADIATED POTATOES. MUSHROOMS, ONIONS AND SPICES IN THE NETHERLANDS. After a brief description of the Dutch public health regulatory approach to food irradiation, the results of technological feasibility and consumer acceptability studies carried out on potatoes, onions and mushrooms at

Wageningen are reviewed. It is suggested that international agreement on the philosophy and guidelines of the testing for wholesomeness of the process of food irradiation be worked out.

INTRODUCTION

The history of the commercialization of irradiated food items in the Netherlands is in fact the history of the Dutch Pilot Plant for Food Irradiation. In 1964 the evaluation of the technological feasibility led to a recommen­ dation to construct a special Pilot Plant for Food Irradiation. This Plant was founded in 1965, constructed in 1966-67 and opened in 1968. The investment capital was shared between the Government and industry. Equipped with a 100-kCi 60Co gamma source and a Van de Graaff 3 MeV X 1 mA electron machine source, the plant was devised to irradiate all food commodities and to be available to any interested industry or marketing organization. Irradiating large batches brought with it the need to market the processed food and for this an approval or clearance for the specific food item or items was required. As early as 1964 — four years before the Pilot Plant opened — a joint commission of the Nutrition Council, the Health Council and the Food Law Advisory Committee issued general rules for such a clearance. These authorities stipulated "it is only permitted to sell irradiated food products under certain specified conditions". The emphasis was put on preventive control, actual and regressive control being impossible because there are as yet no satisfactory methods of detection. The approval or clearance to market irradiated foods is signed by the Minister of Health. He is advised by a com m ission on which are representatives of the Nutrition Council, the Health Council and the Food Inspection and experts in toxicology, microbiology and food technology. There exists in the Netherlands a stepwise' clearing system, explained in Table I [1]. The existence of three successive stages makes it possible for interested parties to have certain food items evaluated before all data for a full clearance are available. For clearance in stage III the commission requires full whole­ someness data. For clearance in stage II data of sem i-chronological tests are generally required. This category is specially meant to find the answers to questions such as packaging, storage period and consumer acceptance.

133 134 de ZEEU W

TABLE I. STEPWISE CLEARING SYSTEM

Q u a n tity S ta g e Purpose (tons)

I Scientific evaluation (organoleptical tests, 0.005 - 0.1 packaging, technology, etc.)

II Restricted quantities with a controlled sale (test 0 . 1 - - 3 . 0 marketing, com mercial or technical evaluation)

III Full clearance for sale and consumption u n lim ite d

TABLE II. FOOD ITEMS AND TREATMENTS ALREADY CLEARED

Item T r e a t m e n t

A sp a ra g u s3 Radurization

Cocoabeansa Insect disinfestation

Strawberries Radurization

M u sh room s Growth inhibition

Deep-frozen meals^ Radappertization

P otatoes Sprout inhibition

S h rim p s3 Radurization

O n io n s3 Sprout inhibition

Spices and condimentsa . Radicidation

Poultry, eviscerated Radurization (in plastic bags)a

Fresh, tinned and liquid foodstuffs^1 Radappertization

a Experimental batches. b For hospital patients in reversed barrier isolation.

The commission has already accomplished a great deal.- Under the chairmanship of Dr. Huizenga it has managed to clear the food'items given in Table II/within 3-6 months following the date of request and on the basis of internationally agreed regulations. Most essential to the work of this commission has been the unanimity always reached so far between the different members. A sound and realistic approach forms the basis for this u n a n im ity . The commission has furthermore started discussions on methods other than the regular wholesomeness test ones. One of these is the analytical approach: on the basis of a theoretical analysis of the chemical changes expected.to result from irradiation a calculation of the possible production of toxic substances is made. This has been done for irradiated endives [2]. COMMERCIALIZATION IN THE NETHERLANDS 135

The commission is investigating the possibility of giving a clearance if such analyses do not produce any evidence of ill effects through irradiation. Finally,,the commission is considering the authorization of the process in 1975 or 1976, after completion of a large-scale pig experiment. For further details see Ref.[3]. After 5 years of operation, on 1 January 1973 the ultimate goal of the pilot plant, namely the full commercialization of one or more food products, had not yet been reached. As we see it, there are three reasons for this: no co-ordinated international authorization policy; insufficient data on the economics of large-scale commercial operations; and technological difficul­ ties during the scaling-up-process for specific products. During these 5 years the pilot plant disseminated much information to possible users. The process is therefore well known in the Netherlands. It was decided to continue for a period of 3 years (197 3—1976) as an irradiation facility in order to find out whether there is any real com m ercial interest. After one year of operation as an irradiation facility it appeared that the industry and food marketing organizations are really interested in the following applications: (a) Potatoes and onions: chemicals (chloride-IPCand maleine hydrazide respectively) do not give a 100% guarantee against sprout forming, especially later in the season, and moreover they often form (or leave) residues; (b) Herbs and dried vegetables; grain and grain products: chemicals such as ethylene oxide are, in fact, unacceptable from the public health point of view; (c) Chicken: the use of deepfreeze storage is not completely satisfactory from the quality point of view; Salmonella, continues to be a problem; (d) Fish: the use of the cold chain by itself does not provide sufficient ^ storage possibilities; (e) Animal feed: again the Salmonella problem; the irradiation of animal feed has proved, in practice, to be more attractive than heat treatm en t; (f) Cut fresh vegetables: the existing food technology processes do not offer sufficient storage possibilities for these types of convenience fo o d s . The following points have also become apparent: (1) The increasing use of chemicals in our environment is causing an increasing number of problems (amount of concern) and so other ways of guaranteeing the hygiene of food are being sought. A statement made by Dollar during the food irradiation congress in Bombay [4] is of direct relevance to this point: "There is a major need for a broad-spectrum quarantine treatment which does not leave a residue. Radiation is the only such broad- spectrum control measure which can be used to treat a wide range of commo­ dities moving in international and national commerce. It is sincerely hoped that the approach will be that of seeking general acceptance of the process rather than applying for clearances item by item". (2) Heat pasteurization and sterilization and deepfreeze storage devour energy. The ever-increasing cost of energy means that processes that use less energy are becoming more interesting. The production of sources of ionizing radiation uses very little energy, whilst the irradiation itself requires only sufficient energy for the propulsion of the transport system and for the safety equipment. 136 de ZEEU W

(3) It is becoming clearer, also to the public health authorities, that the irradiation process is completely safe. It is superfluous to protect humanity from a danger that has never been proved in the long and careful testing to which it has been subjected. I feel we are justified in asking ourselves whether it is responsible to prevent the application of this safe alternative so that other less safe techniques (some chemicals, overheating etc.) cannot be replaced. This notion is also growing internationally. In 1975 a WHO panel of experts will be recalled to consider and report, individually and as a group, on the present situation with regard to the 'wholesomeness' of tested, irradi­ ated food. Perhaps a general clearance of the irradiation process, as such, will then be initiated. (4) An increasing number of developing countries are asking for assistance, recognizing that the irradiation process is especially valuable for them. Their warm and humid climates and less-developed traditional food technologies are primarily responsible for this. Both economic and technical evaluations and clearances are urgently required in these countries. (5) The increasing use of gamma irradiation to sterilize medical and pharmaceutical products has a positive influence on the irradiation sterilization of food packaging m aterial,for instance; especially because gamma-sterilization is a clean process compared with sterilization by means of chemicals (ethylene oxide, methyl bromide, H20 2), for example.

For these reasons we feel that as soon as international authorization has been agreed upon irradiated food will appear in national and international food distribution and trade. The actual situation for a few com m ercially advanced applications will be discussed in the following.

POTATOES

From an evaluation carried out in 1971 [5] the following conclusions were drawn: The potatoes in containers holding 1000 kg should be transported past the radioactive source and irradiated with gamma rays at a dose of 10 krad with a uniformity ratio Dmax/D min = 2. Irradiation should be carried out when the tubers are in the pre-germination phase, i.e. from the harvest in September/October to approximately the middle of December about 10 weeks are available for the irradiation. With respect to the potato irradiation, sufficient data is still not available on two important aspects:

(1) Wound healing and suberization, which are delayed by irradiation and as a result increased attack by Fusarium can occur during storage. It is thus important to avoid all damage before, during and after irradiation. Immediately following harvest a period of 2-3 weeks must be allowed for wound healing before irradiation can take place. (2) The boiling and frying quality of the potato after irradiation: it has been noticed that some lots of Bintje potatoes show a gray colouring after cooking. Thè reducing sugar content in the potato is also higher immediately after irradiation so that it is inadvisable to process the potatoes into chips soon after irradiation, as too dark a coloration of the chips may result. COMMERCIALIZATION IN THE NETHERLANDS 137 I Because insufficient information is available on these two points, further tests will be undertaken with as many different lots as possible to achieve a responsible decision on the process within a short period of time. It follows from a rough estimate of the exploitation costs that irradiation and storage on an industrial scale with bulk storage would cost approximately f.23.- per ton more than without irradiation, f.14.--, or 60%, of these extra costs being accounted for by the source itself. It has been assumed here that it will be possible to store the potatoes in bulk before and after irradiation in the proposed factory in order to avoid damage to the potato as far as possible. If tests, which are to be carried out, do not show that this is possible, it will be necessary to store the potatoes in boxes. The extra cost involved in this case will be f.51.- per ton of potatoes. Discoloration has so far prevented the full commercialization of this product. Research is being carried out to investigate the possibility of eliminating this discoloration. The results so far are somewhat negative.

MUSHROOMS

After having obtained full clearance for the sale and consumption of irradiated mushrooms, a food chain was contacted for a practical test of the commercial possibilities on a national scale. This co-operative effort included the sale of irradiated and non-irradiated products side by side and at the same price. After this test marketing had been completed, various useful conclu­ sions could be drawn regarding further introduction and display of irradiated mushrooms (and other commodities): (1) The commercial experience of irradiated fresh mushrooms is important for the 'fresh' goods trade and distribution. Centralization becomes possible and, in spite of added costs, cheaper; (2) Information printed on the'package guaranteeing freshness is desirable. On one hand, this guarantee can be an incentive for the customer to buy, on the other, it makes the head of the produce department responsible for a necessarily fast-moving supply; (3) Another essential element is thorough and regular support of the sales managers through as many channels of communication as possible; (4) The information featured on the package is very important: (a) sales performed under the irradiation trademark progressed satisfactorily; (b) the labels "Fresh mushrooms" and "Irradiated mushrooms" had an unfavourable effect upon the irradiated item. How much the suggested contrast in freshness and how much the "irradiated" labels are to blame is an open question; (5) With irradiation alone, the external appearance of the mushrooms is preserved better than are the taste and aroma. The limiting factor represented by these two points can be minimized by using irradiation in combination with storage and display at lower temperature; (6) It is advisable to irradiate as soon as possible after harvesting. Contract-farming can therefore raise the effectiveness of irradiation.

Introduction of irradiated commodities on a com m ercial and large scale should always be anticipated by a restricted test marketing, with the co­ operating food chain and under the same circumstances and technological conditions. It should be agreed beforehand that the institute or pilot-plant involved will attend the sale for the time being and that its technological advice will settle the matter. 138 d e ZEEU W

ONIONS

The radiation-induced inhinition of sprouting in onions is a well-known and generally accepted process. As sufficient countries have authorized the irradiation of onions on a com m ercial scale for international trade of irradi­ ated onions to be possible, it is of great importance to study the economic feasibility of the com m ercial application of this product. The annual pro­ duction of onions in the Netherlands is 340 000 tons, averaged over the period 1970- 1973. Of this about 290 000 tons are exported. The storage capacity is about 200 000 t, varying per storage place from 30 to more than 20.000 tons. The losses in weight and sprouting amount in the period March to May are up to 80% of untreated onions and up to 20% of treated (irradiated) onions. Treat­ ment with maleine hydrazide does not guarantee the sprout inhibition of onions during this period, especially not when exported. The amount of onions distributed during the period March to May can be as high as 90 000 to 100 000 tons. It is considered worthwhile to irradiate these onions. Economic feasibility studies started in the Netherlands in 1971. It was found that a 7-d o s e ^ o f 6 krad, applied within a week after the harvest, was sufficient to inhibit sprouting over the full storage period. Some discoloration of the vegetation point took place, but this was considered to be of no practical importance. Further experiments showed that even a dose as low as 4 krad inhibited sprouting sufficiently. We decided, however, for safety's sake to fix the commercial dose at 6 krad. These results led to the formation of an evalu­ ation committee in 1973. This committee has met several times and will finalize its report in mid-1974. Members of the committee are specialists in the following field: research, commerce, source design and organization. A series of final experiments deal with the following aspects: effects in 10 different selections; commercial handling; effects of doses lower than 4 krad; effect of delayed irradiation, especially in mechanically cooled onions (0-2°C). The technical aspects of commercial application are also being studied. A flow sheet has been designed, the model for this flow sheet being one of the largest onion exporters. This exporter is studying the impact of a source in his organization. Finally, the financial implications are being studied. Preliminary results show that the irradiation costs will not exceed 5 cents per kg (2 0 000 tons irradiated in 4 weeks). In the given situation the price will not be the limiting factor. The future for the commercialization of irradiated onions is bright, provided they can be exported to other countries. Therefore authorization in other European countries like Germany, the Scandinavian countries, Switzerland, France and Austria could lead to a breakthrough.

SPICES AND CONDIMENTS

Clearance for a limited quantity has been obtained in the Netherlands. Semi-chronic feeding tests with rats are now in progress in this country and it is expected that the results will lead to full clearance of these irradiated items. The authorities of the Dutch Ministry of Public Health are aware of the importance of this application, being an attractive alternative to the gassing procedure. .Sterilization by ethylene oxide is allowed for medical supplies only. The practical introduction of irradiated spices and condiments, however, COMMERCIALIZATION IN THE NETHERLANDS 139

is hampered by the fact that the use of items containing residues of up to 50 ppm ethylene oxide are still allowed. Many Dutch food manufacturers are interested in the new sterilization technique, but as long as this application is not recognized abroad as being wholesome and generally acceptable, they are not willing to use these radappertized commodities. As many of them export a considerable part of their production, it is quite understandable that the use of this irradiated ^component in products for the home market is very limited. Especially in this field we feel the necessity of international co-operation on a govern­ mental level in order to realize internationally accepted clearances. Only in this way can the future of irradiated spices be secured. Finally, I should like to underline what was summarized during the Symposium on Food Irradiation in Bombay [6] at the end of the session on wholesomeness: There seems to be growing agreement that irradiation should not be regarded as a food additive, and that therefore authorization of the process should be single and granted; Wholesomeness studies, especially those on complete diets, should be carried out on a comparative basis: irradiation be compared with currently accepted technological processes such as heating; There is a growing tendency to apply analytical and integrated approaches instead of testing individual food items — in other words, tracing specific effects and applying integrated diets; How relevant are in vitro tests? Possibly not very relevant, except perhaps in a few specific cases; Administrative authorities should be continuously informed of develop­ ments relating to technology and to wholesomeness.

REFERENCES

[1] ULMANN, R .M ., "Introducing irradiated foods to the producer and consumer". Peaceful Uses of Atomic

Energy (Proc.Conf. Geneva, 1971)'12, UN, New York, IAEA. Vienna (1972) 299-308. [2] ROMKES, S .C .E ., Bestraalde andijvie, een theoretische analyse van chemische veranderingen, Internal

Rep. ITAL (1974). [3] ZEEUW, D; de, КООЦ, J.G. van, "Status of public health acceptance of irradiated food in the Netherlands",

Radiation Preservation of Food (Proc.Symp.Bombay, 1972), IAEA, Vienna (1973) 753-60.

[4] DOLLAR, A .M ., Radiation Preservation of Food (Proc.Symp.Bombay, 1972), IAEA, Vienna (1973) 761.

[5] SPARENBERG, H ., Studie betreffende het bestralen van aardappelen in de praktijk, Meded.IBVL 374,

Wageningen (1971). [6] INTERNATIONAL ATOMIC ENERGY AGENCY, Radiation Preservation of Food (Proc.Symp.Bombay, 1972),

IAEA, Vienna (1973).

PREPARATION FOR THE INTRODUCTION OF FOOD IRRADIATION IN BRAZIL

L. ZONENSCHAIN Economics Group, Brazilian Food Irradiation Programme (APIA), Rio de Janeiro, Guanabara, Brazil

Abstract

PREPARATION FOR THE INTRODUCTION OF FOOD IRRADIATION IN BRAZIL. In th e c o u r s e o f the Brazilian Food Irradiation Programme studies on the radiation inhibition of sprouting of potatoes and onions, the disinfestation of rice, beans, m aize, wheat and coffee, and the prolongation of the shelf-life of some fruits have been carried out. Economic feasibility calculations indicate that large total benefits could be achieved by the introduction of food irradiation. The Brazilian legislation on irradiated

foûds is described and an action pían for com mercialization suggested.

1. INTRODUCTION

Because of the large area of the country (8.5 million km2), the cost of land in Brazil is relatively low and is largely used for agriculture, thus presenting great transportation distances. The country, in spite of the large -• amounts invested in public works, still does not offer an adequate transpor- ’ tation and warehousing infrastructure. These circumstances have been greatly responsible for the large losses of agricultural produce incurred. Food preservation through the process of irradiation can thus generate important social and economic benefits to the country.

2. THE FOOD IRRADIATION PROGRAMME IN BRAZIL

Studies on food irradiation were initiated in March 196 9 with the foundation of APIA Administration for the Food Irradiation Programme, which is part of the "National Nuclear Energy Commission". After pre­ liminary investigation, it was decided to concentrate initially on the appli­ cation of low rates of radiation to foods that are of special interest to Brazil. Thus, sprout-inhibition of potatoes and onions and disinfestation of wheat, corn, rice and beans were initially selected for research purposes. These were selected for the following main reasons: (a) They represent about 50% of the average diet of the population (b) Total losses are high, which could be greatly reduced by irradiation. The annual quantities produced, production value and total estimated losses are given in Table I. The research on food irradiation is co-ordinated by APIA. Food is irradiated in a research irradiator with a 100 kCi 137Cs source loaned by the American Government (Brookhaven National Portable Cesium Development Irradiator). The technical and scientific studies on physiology, bio­ chemistry, microbiology, food technology, nutrition, wholesomeness and

141 142 ZONENS CHAIN

TABLE I. QUANTITY, VALUE AND ESTIMATED LOSSES OF SELECTED PRODUCT

Q u a n tity V a lu e Losses Losses Product (1 0 0 0 t) (U S $ 1 0 0 0 ) '(%> (U S $ 1 0 0 0 )

R ice 7 5 3 3 4 8 8 4 7 0 36 1 7 5 8 4 9

Corn 1 4 2 1 6 4 7 6 3 6 7 16 . 7 6 2 1 8

W h e a t 1 8 4 4 1 9 1 1 3 4 5 9 5 5 6

Beans 2 2 1 1 3 0 5 8 9 4 14 4 2 8 2 5

P o ta to es 1 5 8 3 8 9 3 6 0 2 5 2 2 3 4 0

O n io n s 2 8 5 2 1 6 0 4 30 6 4 8 1

T o t a l 1 5 7 2 8 2 9 2 1 3 3 3 2 6 9

organoleptic studies are done by research institutes and specialized laboratories belonging to the Federal and State Governments. Besides avoiding larger¡ ihvestments, this has the advantage of obtaining trustworthy results an^l als¿ helping to gain the acceptance of such technology among the country's scientists and the population in general. The economic and commercialization studies are still in the initial stages; due to the lack of either a’pilot plant or a sem i-industrial1, one. Such1 studies are co-ordinated by a specialist on a part-time basis' and also 1 carried out |by economy students, also'on a part-time ,basis, for data- collection purpose's, The promotion work together with that of obtaining clearances and the elaboration of standards for food-irradiation are performed by the APIA personnèl.

3. TECHNICAL FEASIBILITY

The experiments with food irradiation in Brazil aim at the results shown in Table II.

3..1. Sprout inhibition of potatoes and onions

Dehydration has been observed in the irradiation treatment of potatoes. The combination of irradiation with refrigeration at temperatures between 5 and 80°C has resulted in an improvement of the product. In addition, the total sugar content remained the same in irradiated potatoes, while it increased in the non-treated ones. Since July 1973 studies have been made on the influence of gamma radiation on the darkening of potatoes after cooking. Types HBT and Bintje were chosen and irradiated 1, 2 and 3 months after harvest with doses of 5, 10, 15 and 20 krad and stored for 12 months at room temperature (in bulk and packed in plastic bags) and at 5 and 10°C. Each month samples were cooked and exposed to air for 18 to 24 hours to check for changes in colour. If any darkening was observed, the sample was analysed in order to determine the intensity of darkening, chlorogenic acid, pH, citric acid, dry material and humidity. FOOD IRRADIATION IN BRAZIL 143

TABLE II. OBJECTIVES OF FOOD IRRADIATION RESEARCH

Product Desired result Handicap elements

P o ta to es 1

R ic e 2 Sitophilus zeamays

Beans 2 Acanthocelides obtectus

Com and corn flour 2 Sitophilus zeamays

Wheat and wheat flour 2 Sitophilus zeamàvs

O n ion s 1

• O ran ges 3 Bacteria and fungus

B ananas 3

Strawberries 4 Fungus

Bread 4 Fungus

C o ffe e 2

(1) Sprout inhibition; (2) disinfestation; (3) ripening delay; (4) fungus inhibition.

Studies on wholesomeness were made with rats using potatoes irradiated at 8 and 16 krad. Observation over 2 generations did not reveal any abnormalities that could be attributed to the irradiated food. The irradiation of potatoes and onions showed very satisfactory results when combined with temperatures between -5 and +10°C and rates of 6 to 10 krad for potatoes and 8. to 16 krad for onions.

3.2. Disinfestation of rice, beans, corn and corn flour, wheat and wheat flour and coffee

Rice was irradiated with 28 krad immediately after the crop and analysed 6 months later. The results did not indicate any accentuated changes in the factors determined (humidity, total glycids, labelled acidity, gross protein, lip id s ). W holesomeness tests on irradiated rice are being initiated using dogs as test animals. Wheat and wheat products were submitted to radiation doses of 5, 10 and 50 krad and occasional superexposures of 600 and 1290 krad. The results obtained showed the following: (a) Irradiation with doses up to 50 krad do not change the baking qualities of wheat flour (b) In some cases a bleaching effect was noticed in irradiated wheat; on the other hand, irradiated wheat flour became slightly darker after irradiation (c) Irradiated flour absorbs more water than non-irradiated flour (d) Irradiation seems to cause a slight modification in the gluten structure by making it become less extensible with increasing irradiation (e) The slight variations noticed in the chemical analysis cannot be conclusively taken as irradiation results. 144 ZONENSCHAIN

It has been observed that for grain disinfestation (rice, wheat, corn, beans) the best results were obtained with a combination of irradiation with doses of 5 to 1 0 krad, the products being packed in Kraft paper or plastic bags, and treating the warehouses and silos with insecticide. With regard to flour, doses of 2 to 8 krad with the product in plastic packages showed good results.

3.3. Other products

The doses and conditions producing good results for certain other products are listed in Table III.

TABLE III. SUCCESSFUL DOSES FOR VARIOUS FRUITS AND WHEAT PRODUCTS

D ose Product Other conditions (k rad )

O ranges 4 0 to 8 0 - 5 to 1 0 ° C Strawberries 1 0 0 to 3 0 0 Г and plastic bags B ananas 2 5 to 7 0 J

Bread 5 0 to 2 0 0 r Plastic bags J Biscuits 5 0 to 1 0 0

4. ACCEPTANCE BY PUBLIC HEALTH AUTHORITIES

The Brazilian health authorities have given their support to the problem of clearances for food irradiation. Thus in 196 9, when research began in the country, the Government already showed their willingness in that direction, defining irradiated food from a legal point of view as follows: "irradiated Food: all food which has intentionally been submitted to the effects of ionizing radiations, with the purpose of its preservation or for other licit purpose, in accordance with standards to be established by the proper office of the Health Ministry. " In August 1973 a general ruling regarding food irradiation was established through specific legislation, as given in the Annex. Thus, once specific standards for each product and instructions regarding equipment, irradiation operation, working conditions and technological processes have been elaborated, irradiated food can be commercialized. The general rules further allow clearances to be granted for irradiated food based on experiments in other countries, with the approval of the "National Nuclear Energy Commission". FOOD IRRADIATION IN BRAZIL 145

5. ECONOMIC FEASIBILITY

5.1. Economic potential

The main economic benefits from food irradiation in Brazil are (a) reduction of losses; and (b) an increase in food production through larger periods of storage, transportation over greater distances and stable prices throughout the year. The reduction of losses and increase in production will.provide larger supplies of food, thereby reducing prices. Price reduction.and better food quality represent important benefits to the co n s u m e r. The consumer benefits deriving from the reduction of losses (B^ can be calculated as follows:

Bi = 4i (Pi - Рг) + (Ч2 " 4 i) (P i - Рг)/2 where: qj is the initial available quantity pi is the average price of qj quantity q2 is the available quantity after loss reduction p2 is the average price of q2 quantity. The consumer benefits deriving from increases in food production (B2) can be calculated as follows:

B2 = q2 (P2 - P3) + (Чз " 42) (P2 - P3)/2 w h ere: q 3 is the available quantity after loss reduction and production in c r e a s e РЗ is the average price of q3 quantity. Total benefits (B) will be as follows:

В = B 1 + B 2

It should be noted that the unit price reductions caused by increases in supply are limited by production costs, i.e. below a given sales price it is no longer of interest to the producer to sell the product. Studies regarding offer and demand and of income and price elasticity of food are still in the initial stage of evaluating the benefits to the consumer. The evaluation of the economic benefits can be calculated by the estimated increase in national income deriving from the reduction of losses and increase in production. Thus, by taking into consideration the production quantities shown in se c tio n 2, we can make the following hypothetical benefit calculations:

(a) Production percentage to be irradiated:

Rice Corn Wheat Beans Potatoes Onions

20% 10% 50% 2 0% 30% 60%

These estimated percentages were based on the possibility of concen­ trating each product for irradiation and on the interest in their irradiation in B r a z il. 146 ZONENSCHAIN

(b) Taking into consideration a zero loss for the irradiated product, this would represent an increase in availability shown in Table IV.

(c) Increase in supplies that would arise through the possibility of extending the storage period and transport distances, and other factors are estimated to be as shown in Table V.

(d) A rigorous calculation of the economic benefits for the country would correspond to a calculation of income increases deriving from loss reduction, estimated under (b) and production increase under (c). A fair calculation of the first item should consider the value of product saved through irradiation, less the cost of the irradiation process itself. Nevertheless, since the irradiation cost is insignificant in relation to the value of the irradiated food, we shall consider the total benefit to be equal to the value of the product saved.

With regard to the increase in supplies, the income should be calculated by taking the total value less the agricultural input and the cost of the irradiation process. One of the main characteristics of Brazilian agriculture

TABLE IV. INCREASE IN PRODUCT AVAILABILITY THROUGH IRRADIATION

Q u a n tity V a lu e Product °Jo ( 1 0 0 0 t) (U S $ 1 0 0 0 )

R ice 7 . 2 5 4 2 3 5 0 51

C orn 1 . 6 2 27 7 6 0 7

W h e a t 2 . 5 4 6 4 7 6 8

Beans 2 . 8 6 2 8 5 7 8

P otatoes 5 . 0 7 9 4 4 6 0

O n io n s 1 8 . 0 51 3 8 6 6

TABLE V. INCREASES Ш PRODUCT AVAILABILITY THROUGH INCREASED STORAGE PERIOD AND OTHER FACTORS

Q u a n tity V a lu e P roduct 1o ( 1 0 0 0 t) (U S $ 1 0 0 0 )

R ice 5 3 77 2 4 3 81

C o m 2 2 8 4 9 5 1 7

W h e a t 2 37 3 8 3 5

Beans 2 4 4 6 0 8 7

P otatoes 10 1 5 8 8 9 1 9

O n ion s 3 0 , 8 6 6 5 1 9 FOOD IRRADIATION IN BRAZIL 147

TABLE VI. ECONOMIC BENEFIT FROM THE IRRADIATION OF CERTAIN FOODS

Product Bi B2 В

R ice 3 5 0 51 2 4 3 81 5 9 4 3 2

Corn 7 6 0 7 9 5 1 7 17 1 2 4

W h e a t 47 6 8 3 0 6 8 7 8 3 6

Beans 8 5 7 8 6 0 8 7 1 4 6 6 5

P otatoes 4 4 6 0 8 9 1 9 1 3 3 7 9

O n ion s 3 8 6 6 6 5 1 9 1 0 3 8 5

T o t a l 6 4 3 3 0 5 8 4 9 1 1 2 2 8 2 1

B! - loss reduction benefits in US $1000; Bj - production increase benefits in US $1000;

В - total benefits.

is the extensive use of land, which is abundant and cheap, rather than using fertilizers, soil correctives, irrigation, mechanization etc. that aim at increasing the production per unit of the area utilized. The increase in the value of agricultural production can, thus, be calculated, with a low margin of error, as equal to the value of the product saved. With regard to wheat, however, which is grown in Brazil with a more developed technology, we shall consider the increase in value equal to 80% of the value of the product saved. Thus we arrive at the economic benefit from the irradiation of selected foods shown in Table VI.

5.2. Agricultural factors

5.2.1. Seasonality of crops and harvest duration

The seasonality of crops and the duration of the harvest are of utmost importance to irradiation econom ics as they affect the length of time that the facilities can be used throughout the year. The following are the harvesting lengths of the products analysed in this report for the main producing regions in Brazil:

R ice

South-Central Region : March, April and May North Region : August and September

C orn

All regions : March to July

■ W heat

All regions October and November 148 ZONENS CHAIN

B ea n s South Region : December, January and May-June Central Region : May-June

P o ta to e s

South Region November to January and May - June Central Region : January and August

O nions

States o f: Rio Grande do Sul : October to December Sâo Paulo : September - October Paraná : September - December Pernambuco : April - August

5.2.2. Facility-sharing by different crops

Using the same facility for crops with different harvest periods permits better utilization of that irradiation facility. On the other hand, it is advisable to use products that have certain characteristics in common or at least are similar so that they can be processed in the same facility. M ore­ over, the irradiation dose should not vary too much from one product to another: product density, either in their form or in the package in which they are to be irradiated, should be as constant as possible and the form (packed or in bulk) in which the products are transported should be similar, etc. Taking this into consideration, it is very likely that the following groups of products can share the same irradiation facilities: (a) Rice and wheat (b) Potatoes and onions. In Brazil potatoes and onions, which are products that should be irradiated close to the producing centre, offer additional advantages to sharing an irradiation facility in that the main producing regions of each product are not too far away from each other. Table VII shows the production of potatoes and onions by the main States. The advantages of using the same

TABLE VII. PRODUCTION OF POTATOES AND ONIONS IN TONS

S ta te P o ta to es O n ion s T o t a l

Rio Grande do Sul 37 1 4 8 8 1 2 9 3 4 3 5 0 0 8 3 1

S S o P aulo 3 5 7 4 6 1 4 9 5 5 9 4 0 7 0 2 0

Paraná 4 1 0 0 8 5 2 5 9 2 9 4 3 6 0 1 4

Minas Gerais 2 3 7 6 1 3 1 5 7 3 3 2 5 3 3 4 6

Santa Catarina 1 7 1 6 1 5 1 8 6 8 4 1 9 0 2 9 9

Other states 3 5 2 0 3 4 5 3 5 5 8 0 5 5 8

B ra zil 1 5 8 3 4 6 5 2 8 4 6 0 3 1 8 6 8 0 6 8 FOOD IRRADIATION IN BRAZIL 149

FIG. 1. Harvest and irradiation of potatoes and onions in the Rio Grande do Sul State (quantities in thousands o f to n s).

irradiation facilities for the potato and onion harvests can be seen immedi­ ately, especially for Rio Grande do Sul where there is a better balance between the quantities produced. Figure 1 shows the potato and onion harvest seasons in Rio Grande do Sul and a hypothesis on the allocation of irradiation periods of time and processed products quantities in order to obtain an advantageous utilization (8000 h/a) of the facilities. The month of September, in the present instance, could be reserved for facility maintenance.

5.2.3. Techniques of potato and onion harvesting, transportation and storage

(a) O nions

The harvesting point is indicated when the leaves become dry. The bulbs are then pulled out manually and exposed to the sun for one or two days so that they lose their excess water. Afterwards they are stored in cool, ventilated rooms that are dry and protected from the sun. Storage can be in bulk or in pleated strands, the latter being more frequently utilized, the strands tied together in twos and hung high up in the room. The onions are stored thus close to the producing centre for up to about 4 months. Usually, the trader tries to store the product for as short a time as possible, preferably not longer than 15 days. In this case, the onions are transported to the trader's warehouse, stored and afterwards sent to the sales locations, in two form s: in pleated strands of about 25 onions or in well-ventilated plastic bags of 50 kg, which is the most common. The onions are usually transported in ordinary lorries. To permit a rational use of the production process, the main aspects to be considered are the packaging of the product and production concentration through some form of commercial mechanism. 150 ZONENSCHAIN

Irradiation of onions costs more when packaged in pleated strands than when loose, whether in bulk or packaged. This is because the pleated strands represent 5-10% of the total weight. On the other hand, irradiation of the onions after separation from the pleated strands, although cheaper, subjects them to greater losses from putrefaction. Both alternatives are being studied in the country, but no conclusions have yet been reached. Concentration of production is of utmost importance to the economics of the irradiation process. The best solution to the problem seems to be the stimulation of producers' co-operative societies, some of which have already been set up. Great benefits are expected from onion irradiation, since the use of chem ical products has not been well accepted and the installation of refrigeration facilities involves high costs.

(b) Potatoes

The potato harvest, which takes place from 3 to 4 months after planting, is still perform ed manually with hoe and plough in the majority of Brazilian farms, although several producers already apply mechanization. After harvesting, the potato is cleaned, graded and bulk stored close to the producing centres. It is advisable to use cool warehouses with a good air circulation and protected from light. Potatoes are transported in normal lorries and packed in 6 0 kg jute bags. The winter crop can be stored for about 3 months without sprouting, whereas the summer crop should not be stored for more than 30 -45 days. The problem of production concentration for irradiation is already partly solved since some big traders finance the growers, who thus become obliged to sell their production to the trader. Besides, some of the existing co-operative societies also tend to concentrate crops of the small growers. Chemical sprout inhibitors are usually not well accepted, which is an additional reason for irradiating the product. Moreover, the high storage cost through refrigeration indicates irradiation as rather attractive alternative.

5.3. Technical and organizational factors

Brazilian research is at present at a stage that does not yet allow the technical and organizational characteristics for the food irradiation to be defined. Nevertheless, in the case of sprout inhibition of potatoes and onions, and taking into consideration the hypothesis shown in section 5.2, the following characteristics can be anticipated:

(a) Potatoes and onions would be irradiated in bags of 6 0 and 50 kg respectively, in which form they are commonly transported and stored by traders and retail dealers; under such conditions, the packed- product density is about 0.8 and 0. 7 respectively

(b) A conveyor transportation system, before, during and after irradiation, seems to be the most convenient FOOD IRRADIATION IN BRAZIL 151

(c) Irradiation should be continuous

(d) In the quoted instance, the production capacity should be of 20 000 t/month, i.e. about 28 t/h; in this case, using average doses of 8 krad for potatoes and 12 krad for onions and considering a source efficiency of 0.30, we would need a 180 kCi source; the maximum dose for potatoes should not exceed 10 krad (overdose of 1.25) and 16 krad for onions (overdose of 1.33).

5.4. Commercial factors

Although none'has been marketed so far, we do not expect any difficulty from the consumption of irradiated food in Brazil. In the main consumption centres of the country the distribution of food is being technically improved by the erection of large supply facilities, where the marketing techniques will certainly profit from food irradiation. ^ At present there are practically no opposing commercial interests, especially in the food industry, for the products to be initially irradiated in Brazil. What can be observed is the industrialization of these products on the initiative of big traders or producers1 co-operative societies as an alternative to preserving their agricultural products for a longer period o f t i m e . Food irradiation should result in steadier prices, larger and more constant supplies throughout the year, and the extension of market distances, also permitting an increase in exports. Even if these factors cause an average price reduction, we believe that the increase in production will benefit both producers and traders.

5.5. Psychological factors

Brazil has been developing a long-range promotion plan aiming at clarifying public opinion with regard to irradiation through frequent articles in the press, radio and television. In addition, courses at several levels for teachers and conferences in universities are being held to explain food irradiation techniques, their applications and advantages. Simple books for children have been distributed in the primary schools and a similar campaign is being prepared for high-school students. The attitude of public health officials, politicians and the press in general to irradiation has been favourable. On the other hand, we still have no consumer information as neither public opinion research nor marketing tests have been held. We believe that irradiated food will be well accepted in the large centres. Nevertheless, its total introduction in the smaller centres can only be on a long-term basis.

6. ACTION PLAN

Taking into consideration that a number of irradiated foods have already been cleared for consumption in several countries, it would seem that the main obstacle to the utilization of these products in other countries, assuming that the process is economically feasible, is the lack of under­ standing by the public and, the authorities. On the other hand, we believe 152 ZONENSCHAIN

that, since irradiation is a new form of food processing, its promotion should be thorough, intensive and aimed at large-scale results. These can only be obtained by the use of the multimedia (cinema, television, press) and through medium and long-range explanatory campaigns. The frequent organization of conferences and courses at various school levels, in the Army, Navy and Air Force, and in syndicates, agricultural co-operative societies, etc. also represents an important item towards the public acceptance of irradiated food. On the other hand, international trade in irradiated products would be of great help in introducing this new technique. In this case we believe that action by the International Atomic Energy Agency in association with the national agencies of the irradiated-food importing countries aimed at obtaining a favourable attitude among public health officials would be of great importance. The import of adequate quantities of irradiated food would allow those countries that have not yet invested in irradiation facilities to test the market without the initial high costs. This would also help create a market for irradiated food, thus stimulating the related investment in facilities.

ANNEX

DECREE No. 72.718, DATED 29 AUGUST 1 973, IN WHICH ARE DRAWN UP GENERAL REGULATIONS GOVERNING THE IRRADIATION OF FOODSTUFFS

The President of the Republic, in exercise of the right conferred upon him by Article 81. Ill of the

Constitution, and in consideration of the provisions of Article 59 of Decree-Law No. 986 of 21 October 1969,

ordains that:

Art. 1. The preparation, storage, transportation, distribution, importation, exportation and display for sale or delivery for consumption of irradiated foodstuffs shall be regulated throughout (Brazilian) national territory by the provisions of the present Decree.

Art. 2. For the purposes of this Decree irradiated foodstuffs shall be taken to mean any food which has deliberately been exposed to the action o f ionizing radiations with the aim of preserving it, or for some other legitim ate purpose, in conformity with such standards as may be established by the competent body of the Ministry of Health.

Art. 3. The ionizing radiations applied to the foodstuffs shall, as a general rule, be those with energy

lying below the threshold of nuclear reactions which could induce radioactivity in the irradiated material.

Art. 4. The irradiation of foodstuffs for purposes of display for sale or delivery for consumption, or for

industrial use, shall be effected only by establishments duly licensed by the competent authorities, and after authorization by the National Nuclear Energy Commission.

Special clause: The National Nuclear Energy Commission shall issue instructions governing the registration of irradiation equipment, operating conditions and the technological processes to be used by the

licensed establishments.

Art. 5. Authorization shall be given only for the irradiation of foodstuffs or groups of foodstuffs for which technical and scientific data obtained by national or international research establishments and duly

approved by the National Nuclear Energy Commission are available, and from which there is confirmation of

(a) The harmlessness of the irradiated foodstuff for consumption;

(b) The extent of the effect of the irradiation on the principal nutrients in the foodstuff, as compared

with losses that occur through the processing of foodstuffs by conventional methods; FOOD IRRADIATION IN BRAZIL 153

(c) The wholesomeness of the irradiated foodstuff and the effectiveness of the irradiation for the given o b j e c t i v e .

Art. 6. It shall be incumbent on the National Commission for Food Regulations and Standards of the Ministry of Health to draw up, on the basis o f recommendations originating solely with the National Nuclear Energy Commission and of the scientific and technical data referred to in the previous Article, a Table of

foodstuffs or groups of foodstuffs for which irradiation is authorized, indicating in each case the type and level

of radiation energy that may be used, the nominal dose to be applied, the purpose of the irradiation, and any

processing that must be carried out before, during or after the irradiation to attain the desired objective.

Art. 7. From each batch of irradiated foodstuffs samples shall be taken, in accordance with instructions

issued by the competent technical body, to be placed at the disposal of the competent authorities for official a n a ly se s.

Special clause: The samples referred to in the present Article shall be accompanied by a formal report

signed by the person in charge of the food irradiation process, in which the following information shall be given:

(a) The purpose of the irradiation;

(b) The radiation source, energy and dose, and details of the ambient conditions prevailing during the irradiation;

(c) A description of any processing which the foodstuff may have undergone before, during or after the irradiation;

(d) The type and nature of the packing material used for packaging the irradiated food; and

•(e) Conditions and duration of storage proposed for the irradiated food.

Art. 8. The irradiated foodstuffs, when displaced for sale or delivered for consumption, shall be marked on their, packaging and on any labels attached at the place o f sale or delivery for consumption: "Food processed

by irradiation", and also bear the statement: "This product has been processed at an establishment approved by the National Nuclear Energy Commission".

Art. 9. The irradiated foodstuffs, when delivered for consumption, shall conform to the normal standards of identification and quality unless the National Commission for Food Regulations and Standards has approved a special standard of identification and quality for the irradiated foodstuff in question.

Art. 10. The use of additives in foodstuffs which are intended for irradiation or which have been irradiated shall be subject to prior authorization by the Commission referred to in the previous Article.

Art. 11. Any agricultural pesticide residues or other impurities present in foodstuffs intended for irradiation, or already irradiated, shall be within the limits fixed by the National Commission for Food Regulations and Standards o f the Ministry of Health.

Art. 12. The provisions of this Decree and other supplementary regulations shall apply, wherever appropriate, to imported irradiated foodstuffs.

Special clause: Imported irradiated foodstuffs shall meet the requirements set forth in Article 6 and in the special clause of Article 7 of this Decree.

Art. 13. Irradiated foodstuffs intended for export m ay be prepared in conformity with the regulations in force in the country for which they are intended.

Art. 14. Failure to observe and com ply with the provisions of this Decree and any supplementary regulations appended thereto constitutes a breach of public health legislation, making the violator liable to the penalties provided for under Decree-Law No. 785 of 25 August 1969.

Art. 15. The present Decree shall enter into force on the date of its publication, its dispositions being annulled in case o f the contrary.

Brasilia, 29 August 1973 Emilio G. Méstet

The 152nd year of independence and Mário Lemos the 85th of the Republic. A n to n io D ia s L e ite Jr.

STATEMENTS AND STATUS REPORTS

STATEMENT OF THE WHO REPRESENTATIVE ON THE WHOLESOMENESS OF IRRADIATED FOODS

M . SENTICI World Health Organization, Technical- Liaison Officer to the International A tom ic Energy Agency, Vienna

The World Health Organization is particularly concerned about the safety and wholesomeness of irradiated food items. It is to safeguard these aspects that WHO collaborates with other organizations to identify basic criteria that would lead to a coherent policy for the international health authorities. WHO interest in the commercialization of irradiated food items is, however, limited to those items that have been declared completely harmless and wholesome and it is appropriate to emphasize that for WHO this is not yet the case. For some products a temporary clearance had been recommended, but this recommendation should not be extended to other items. The Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food with Special Reference to Wheat, Potatoes and Onions, which met in Geneva in 1969, (TRS No.451) recommended clearance of irradiated potatoes and wheat on a temporary basis only, because the available data were still insufficient for a permanent clearance to be recommended.

157

PUBLIC ACCEPTABILITY OF FOOD IRRADIATION

G. PROPS TL EURISOTOP O ffice, European Communities, Brussels

While the harmlessness of food irradiation is essential to its introduction, this is a problem to the solution of which we cannot contribute very much for the present and about which specialists in other fields are competent to speak. This is rather an occasion for considering the public acceptance of irradiation from other important aspects, whether they be of a technical or non-technical, an economic or non-economic, a rational or non-rational nature. For the fact is that irradiation has not gained sufficient public acceptance — a fact which should give us grounds for thought. I should like to use this opportunity to go a step further, however. There is certainly considerable room for improvement and scope for change as regards public opinion, but we have to take public opinion as it is — even though it fails to recognize the advantages of the best techniques and even though we complain about it so bitterly or formulate suggestions for improving the situation. Accordingly, I propose to change camps and join the.other side by speaking about the 'public acceptability' rather than the 'public acceptance1 of irradiation. What I have to say will thereby necessarily assume a self-critical character; on the other hand, it will relate to the area where changes can most easily be made — namely ourselves. And I would ask you to consider whether a collective reappraisal of our own actions and motivation might not lead to greater success.

THE SCIENTIFIC DOSSIER

Reference was made, in our discussions, to the pile of documents over one metre high which is necessary in order to obtain clearance for an irradiated commodity. How thick would a dossier'containing all the scientific data at present available on food irradiation be? I don't know, but I am sure that during the past 20 years — since food irradiation research started — the amount of technical data accumulated has been excessive rather than insufficient relative to what has been achieved in practice. And we are still studying the technicalities of the problem, so that even more scientific data are accumulating. We rightly complain about the slowness of the authorities in issuing clearance for irradiated commodities, yet — with rare exceptions — when a clearance is issued, no-one makes use of it unless financial support from the public purse is forthcoming. The interest of the general public, of industry, of business and of the consumer in irradiation is very slight. That being so, ought we not to ask ourselves whether the very limited practical use made of food irradiation still justifies the considerable expenditure on it?

159 160 PRÔPSTL

This is a deliberately provocative question, and I intend to continue in the same vein. In doing so, I may go too far in my harsh analysis of the situation for the liking of some of you. This prospect does not deter me, however, for I know there is no danger of creating false impressions among people with your critical faculties, and a harsh analysis may help the Panel in re-thinking the strategy employed so far and in finding a new approach. No one will deny that it is useful — or even necessary — to question one's own position from time to time.

PUBLIC ACCEPTABILITY

The public acceptability of irradiated commodities has very little to do with the size of the scientific dossier. Entirely different factors, of which I shall discuss a few, are involved. Even a question as fundamental as whether the public knows what it is being asked to accept is justifiable, for the words 'food irradiation' are not very informative. One cannot expect the consumer to accept an irradiated c o m m o d ity ifhe does not know the purpose of the radiation treatment. We have no difficulty in explaining the reasons for irradiation — in fact, we have a large number of precise technical expressions available for that purpose: radurization, radicidation, radiopasteurization, radiodisinfestation, radiosterilization and inhibition of sprouting. Despite their precision, however, these expressions evoke associations with 'hospital', 'vermin', 'sterility', 'death1, 'mothballs', etc. Can one honestly expect irradiation to be accepted by the public when its objectives are expressed in terms that could hardly be further removed from the idea of good cuisine and a cosy restaurant? In describing the objectives of irradiation we must have much more consideration for the sensibilities of the gourmet and the economical housewife, and we must recognize that irradiation suffers the handicap of having sprung from the heads of scientists as the first completely new preservation technique in a long time. There are techniques whose practical success is inversely proportional to the scientific effort involved in developing them. With some techniques one even gets the im pression that they have failed to be applied in practice because so much attention had to be paid to all the possible scientific facets. Perhaps one should feel envious that earlier preservation techniques became accepted without such scientific exertions, for it is certainly questionable whether roast pork and smoked ham would ever have delighted the palate if their introduction had depended on the conclusive results of investigations by as many chemists, physicists, biologists, toxicologists, food hygiene specialists, m icrobiologists and so forth as are engaged in investigating different aspects of food irradiation.

THE ACCEPTABILITY OF OUR EFFORTS

We ourselves know exactly what we are trying to achieve through our efforts — we are trying to prevent foodstuffs from deteriorating and to offer the consumer foodstuffs of high quality. However, such a general statement will not gain recognition of our efforts by politicians, administrators, professional associations, industry, commerce and — above all — the public PUBLIC ACCEPTANCE 161 at large. We must be more specific about our aims, though without going into excessive detail. An aim stated in very general terms lacks the substance and the credibility necessary to attract the active support of a responsible personage without specialized knowledge. An aim stated in great detail, on the other hand, makes excessive demands on such a personage's comprehension and willingness to act as advocate. We must therefore confine our efforts to major objectives which are generally recognized as being worthy and which can be described in simple terms. A public statement of priorities would not preclude our occasionally being more ambitious in our efforts when warranted by particular local circumstances, while the priorities would provide the motivation for our efforts and above all for those of the personages and organizations called upon to speak on our behalf in economic circles and many other fields of public life. I propose that we pursue three major objectives:

(1) To keep the radiation dose so low that no effect — or no significant effect — apart from the desired one is produced in the irradiated commodity, the desired effect being a specific change in foreign organisms (e.g. insects) or in particularly radiosensitive components (e.g. germ cells). This is the gentlest way known so far of treating foodstuffs, whose properties — especially nutritional value, taste and chemical composition — remain virtually unchanged; by such a procedure one can, for example, inactivate insect pests in cereals, flour, dried fruit and nuts and inhibit the sprouting of potatoes, onions and garlic. Chemical methods of preservation can have a deleterious effect on foodstuffs, which usually contain chemical residues after treatment by such methods. (2) To irradiate luxury or semi-luxury food commodities in such a way that, while irradiation is more costly than other preservation methods, the high quality of such items — especially as regards nutritional value, taste and other specific properties — is better maintained. An example of this kind of treatment is the irradiation of shrimps, which can otherwise be preserved only by using chemicals, by canning, by deep-freezing or by freeze-drying, all of which procedures have more or less detrimental effects on the taste of the commodity. (3) To employ radiation in cases where the usual preservation methods are questionable from the health point of view. It is well known that many such methods have established themselves in the field of food technology, the official attitude towards them ranging from prohibition, via restrictive legislation — aimed at minimizing damage to health — to a degree of indifference which is hard to justify. Admittedly, the official attitude is determined by many factors — such as the level of scientific knowledge, consumer habits, food shortages, agricultural production, technological knowhow and climatic conditions; when, however, questionable methods can be replaced by perfectly safe forms of radiation treatment, one is surely entitled to expect the support of politicians and officials for irradiation, even if the costs are slightly higher than those associated with conventional m eth od s.

In my opinion, such cases have not yet been investigated as systematically as they should be. I shall mention here but a few of them: 162 PRÔPSTL

(a) Egg-white is very temperature-sensitive, so that in the thermal pasteurization of dried and frozen egg for use in the food industry only slight heating is possible and consequently not all pathogenic m icrobes are destroyed, while the addition of chemicals in order to reinforce the effects of heating is inadvisable for health reasons. Thermal pasteurization could be replaced by irradiation; (b) The treatment of stored potatoes with chemicals, in powder or gas form, for the purpose of sprout inhibition is forbidden in many countries for health reasons. In some other countries maximum concentrations are stipulated; with large quantities of potatoes, however, it is difficult to regulate the treatment. M oreover, the effect lasts only a few months so that the treatment has to be repeated if the storage period is longer. This problem would not exist if the potatoes were irradiated; (c) Ethylene oxide is used in the disinfestation of stored grain and of spices despite the fact that the harmfulness to health of ethylene oxide and similar compounds is well known. There is some justification in the case of spices as the damage to health caused by pathogen-contaminated spices has to be set against that caused by ethylene oxide. If ionizing radiation were employed, it would be possible to prohibit the use of ethylene oxide and other fumigants (ethylene oxide has already been largely replaced by irradiation in the sterilization of medical and surgical instruments); (d) Bone and fish meal imported from southern countries or the animal feed made with it must normally be disinfected. Decontamination of the animal feed is achieved by pelletization at fairly high temperature, but experience has shown that decontamination is complete only if really high temperatures are employed; however, there is then the likelihood that much of the nutritional value of the feed will be lost. On the other hand, imcompletely decontaminated animal feed favours the spread of salmonellosis, as has been demonstrated on a number of occasions. To prevent the spread of Salmonella bacteria, it would be necessary to irradiate all bone and fish meal at the ports of entry or the made-up animal feed before its distribution.

TABLE I. OBJECTIVES OF IRRADIATING VARIOUS COMMODITIES

Major objective Commodity (see text)

1 2 3

Potatoes x x

S h rim p s x

S p ic e s x x

G rain x x

Onions, garlic x

Cocoa beans x x

Strawberries, asparagus x

Mushrooms x PUBLIC ACCEPTANCE 163

I believe that, by explaining the three major objectives which I have mentioned — or similar objectives — to the authorities and the public, we would gain much greater understanding for our efforts. At all events, the delimitation of objectives is preferable to general talk about food irradiation or food preservation. And it is not enough, in my opinion, to speak about the irradiation of a particular commodity without relating it to one of the three major objectives stated by me or to some similar o b je c tiv e . A further advantage of stating m ajor objectives is that m ore than one such objective is being pursued in the case of many commodities, as can be seen from Table I.

ACCEPTABILITY FROM THE HEALTH POINT OF VIEW

I do not propose to give a scientific presentation concerning the toxicological aspects of food irradiation; instead I shall speak about the acceptability of irradiated foodstuffs as a decisive factor in the general acceptance of irradiation. To start with, there is so far no evidence that the consumption of irradiated foodstuffs is harmful to health. If extremely high doses are employed, a commodity can undergo serious changes. However, the taste of 'over-irradiated 1 foodstuffs undergoes such severe changes that they are rejected by the consumer (in this respect, irradiation does not differ in principle from certain other food preservation methods). M oreover, economic considerations militate against the application of excessively high doses. This does not mean that the value of wholesomeness studies which have been carried out on irradiated foodstuffs are to be questioned. On the contrary, it is a pity that the harmlessness of other food preservation techniques is not investigated with the same thoroughness. Looking back, I should like to emphasize the great achievements of American scientists and organizations in the field of food irradiation. As luck would have it, however, it was precisely their pioneering efforts which aroused public misgivings. I am sure that these misgivings are unfounded, but we must take them seriously for the consumer is old-fashioned and emotional rather than rational in matters of food and health. The mere fact that the technique of food irradiation derives from nuclear technology gives rise to consumer resistance based on mistaken notions about health. Consumers in the United States of America may be less prejudiced, but in Europe the attitude towards food irradiation was at one time conservative perhaps precisely because this technique was publicized so much in the United States as a piece of 'technological spin-off' from nuclear energy. M oreover, the fact that the need to facilitate the maintenance of food supplies to the troops stationed overseas was given as a reason for the Americans' initial efforts to introduce food irradiation gave rise to a negative attitude which even enlightened people could not avoid sharing to some extent. Perhaps this negative attitude is also more prevalent in Europe, for who in Europe has ever appreciated army food because of its culinary excellence? Thus, food irradiation — which was already under a cloud because of its nuclear origins — became associated with 'war', 'deprivation' and 'barracks'. Besides that, most of the research work was done at a US Army scientific establishment, the first major application 164 PRÔPSTL being the sterilization of bacon. But the word 'sterilization' (again perhaps m ore in Europe than in the United States) is hardly calculated to evoke a positive reaction on the part of the gourmet. It certainly does not fit in with one's ideas of good French, German or Italian cooking, which can still offer the gourmet — perhaps precisely for that reason — the prospect of a Lucullan feast. F in a lly , in 196 8 press reports strengthened the antipathy towards food irradiation even more. The US Food and Drug Administration voiced m is­ givings, applications for the clearance of various irradiated products were withdrawn and food irradiation was back where it had started — even further back in fact, for many people were left with the impression that something may have been going on in the field of food irradiation which was not compatible with concern for the public food. That perhaps is enough about the unfortunate phenomena which have accompanied the great efforts made in the United States; I hope my friends there will not take amiss what I have said. Now I should like to refer to work done elsewhere. The Seibersdorf Project was certainly free of any military associations, being after all supported by organizations belonging to the United Nations family. But even specialists in the field could not offer sufficient justification for irradiating fruit juices; so what justification could an outsider be expected to find? Just at that time the question of radiation-induced changes in flavour was very much under discussion. It might have proved possible to limit such changes severely or to suppress them altogether in the case of fruit juices; but it must be remembered that fruit juices and wine — all beverages in fact — tend to be drunk more, for enjoyment than out of necessity, and people in search of pleasant taste sensations are unlikely to take kindly to logical arguments explaining why they should drink a particular beverage in spite of everything. In my opinion, the latest development relating to the acceptability of irradiated foodstuffs from the health point of view — the project organized by the IAEA, FAO and OECD -- should please everyone, for it is confined to a scientific study of the wholesomeness of irradiated products as regards the public health, and technological and economic considerations are left aside. I hope that through its exclusive emphasis on the health of the consumer this International Project in the Field of Food Irradiation will prove immune to the attacks of critics. The project can be compared to an international court sitting in judge­ ment on irradiated commodities, which correspond to the 'accused', who is being held in a 'legislative prison’ because of his alleged dangerousness. It is for those engaged in the project to determine for the irradiated commodities in question whether such restriction of freedom is justified. If no harmful effects on health are found, if — in other words — the 'guilt' of a particular irradiated commodity is not proven, the competent national authorities will be at liberty to release that commodity. However, as in any court case, some mud always sticks, especially when the accused is acquitted because the evidence against him is insufficient. It would be better for food science and the consumer if food irradiation were to gain acceptance not through such 'court proceedings' but through a 'contest' among all processes designed for achieving a particular objective. In the international project to which I have referred, comparisons are being PUBLIC ACCEPTANCE 165 made between the wholesomeness of irradiated foodstuffs and that of non- irradiated foodstuffs. However, such comparisons yield only a partial answer; the other, competing processing methods should be covered and the place of each in the treatment of food for human consumption deter­ mined. The best method should then be duly emphasized. This would correspond more closely to the needs of the consumer. For example, the comparison between irradiated and non-irradiated potatoes (however appropriate it may be) is irrelevant in practice as most of the potatoes .on sale in the shops today are not untreated — they have been treated with IPC/CIPC. The consumer wants to know whether irradiated or chemically treated potatoes are more wholesome. I think such a broader approach should be encouraged at a time when so much is being done in the field of consumer protection, not because food irradiation would thereby more easily shake off its reputation of being a harmful technique but because the consumer has a right to know where the place of irradiation is among the different technical possibilities.

ESTABLISHING THE PLACE OF THE IRRADIATION METHOD

The irradiation method of food preservation derives largely from the nuclear sciences, and their carriers are still governmental or State establishments. In that respect its position is a special one — a further reason for its isolation from industry and commerce. I believe that the time has now come for food irradiation to relinquish its privileged position and to prove itself like other food preservation techniques. This requires above all that the arguments in favour of food irradiation be put more forcefully. The opponents of irradiation are often quite aggressive, even biassed, whereas the irradiation specialists hardly react at all for most of them are scientists, interested more in the solution of scientific problems than in practical applications. The situation is rather like that in party politics — the party that does not dare to speak of its own virtues and its opponents' faults has no chance of being elected. I wish the proponents of food irradiation would speak up more boldly — something which they ought in any case to do in view of their responsibility to the consumer. If the specialist cannot make propaganda for this technique, who can ? This very necessary confrontation with other methods would throw light on other aspects of the irradiation method and give it a better chance of establishing itself economically, politically and socially. So far it has not established itself. Many people ask why the method should be promoted. Is it simply because the method has glamour or has become fashionable? Is the method simply a means of finding uses for radioisotopes or of keeping laboratories in business? Or is it all simply a way of making certain national or international organizations happy? The confrontation between the irradiation method and other methods must, in my opinion, be conducted on a wide front if the position of food irradiation in food technology, industry and agriculture, trade and politics is to be clearly defined. The time is ripe — more than ripe, in fact — for such a confrontation. As regards the general public, the confrontation 166 PRÔPSTL should result in national and international food irradiation policies which take into account all aspects of the question and reflect the economic and social needs of the population rather than the preferences of the expert. This Panel will undoubtedly help in developing arguments for the confrontation. NOTES ON THE FOOD IRRADIATION PROGRAMME IN ITALY WITH PARTICULAR REFERENCE TO POTATOES

D . BARALDI Laboratorio per le Applicazioni in Agricoltura, CSN, Casaccia, Rome, Italy

INTRODUCTION

The use of ionizing radiation to extend the storage life of potatoes, garlic and onions by sprout inhibition has become more and more important over the last few years. Several European countries recently cleared irradi­ ated potatoes (Spain, France and Italy), onions and garlic (Italy) for public consumption. After a number of years of indecision, government authorities seem now to accept the idea that food irradiated at low doses is harmless and safe for human consumption. However, a number of problems have to be resolved to bring this new technology into the com m ercial phase and also to convince farmers and businessmen that irradiation is competitive with traditional methods of food preservation in terms of processing cost and product quality. We know that several factors like dose homogeneity, methods of trans­ portation and handling, type of container, manpower, extent of plant utilization during the year, are vital for both economic processing and the final aim, which is good and long storage of the products. We know also that varietal factors, health of tubers, time of irradiation and proper irradiation conditions in terms of dose rate may play an important role and may seriously affect the final result. In this respect much has been done, and experimental research, carried out all over the world during the last couple of decades has contributed to the solution of the majority of these problems. In this communication I shall briefly illustrate the food irradiation research carried out at the Casaccia Nuclear Center. Then I shall introduce the recent legislation approved by the Italian Ministry of Health, which allows the commercialization and public consumption of irradiated potatoes, onions and garlic. Finally, I shall present some considerations on the economic and technological problems that have been faced in the course of our p r o g r a m m e .

FOOD IRRADIATION PROGRAMME AT THE CASACCIA NUCLEAR CENTER

Since 1968 a large number of studies and research projects have been carried out in the Food Irradiation Programme at the Laboratorio Appli­ cazioni Agricoltura of the Italian National Committee for Nuclear Energy (CNEN). Among other research projects, particular effort has been devoted to increasing the marketing life of citrus fruits (oranges, lemons, nectarines)[l- 5], tomatoes [6-9], strawberries [10- 12], to the radicidation of dried and frozen

167 168 BARALDI

eggs against Salmonella contamination [13], to the recognition of irradiated foods [14-17] and to developing the technology of potato, onion and garlic sprout inhibition [18-24]. The research project on the technology of potato sprout inhibition has been carried out under the programme promoted and sponsored by the Bureau EURISOTOP during the years 1969-1972. Within this programme several research laboratories, institutes and processing industries, belonging to five countries of the European Community (Fed. Rep. Germany, Belgium, France, Italy and the Netherlands), contributed to the programme which was divided into two phases. The first, from 1969 to 197 0, was carried out at the national laboratory level, dealing with preliminary experiments and was intended to work out the conditions for the industrial test, which represented the second phase. Within the frame of the EURISOTOP programme, the Italian working group of the Laboratorio Applicazioni Agricoltura, carried out three experi­ ments. The first (1969-1970) was conducted on Bintje cultivare (Dutch import), comparing irradiation and chemical treatments. The results demonstrated that irradiation preserves tubers up to 10 months from harvest [18, 22]. This was accompanied by a considerable reduction in weight loss, resulting from complete inhibition of sprouting. The second experiment (1970-1971) was carried out on Maritta and Bintje cultivare (Italian production) irradiated in 1 X 1 X 1 m industrial pallet boxes [20] in order to reduce handling of tubers, manpower, transportation and irradiation costs. After 9 and 11 months of storage at ambient temperature, the samples were processed into chips by the PAI potato chip factory in Rome [24]. This experiment confirmed the superiority of irradiated against chemically treated potatoes [19]. In the third experiment (1971-197 2) investigations were conducted on Tonda, Maritta and Majestic cultivars. Potatoes were irradiated under the same conditions (1 X 1 X 1 m pallet boxes) at an average dose of 12 krad (Dmax /Dmin = 2 .52) and stored in unconditioned warehouses. Potatoes were processed into chips again at the PAI factory 9 months after harvest [19]. Only irradiated potatoes were processed because the chemically treated potatoes (IPC) were unprocessable at that time. Beside the technological aspect of potato irradiation and the industrial processing into potato chips, chemical and biochemical research has been carried out within the Italian group, dealing particularly with vitamin deter­ mination [18, 21-23], sugar metabolism during storage [21, 23], and the nitrogen content [23] in irradiated, chemically treated and unirradiated p ota toes. Our experiments on the possibility of applying ionizing radiation for long-term storage of the major Italian potato cultivars confirm the following p oin ts: (1) Irradiation at the proper dose causes complete sprout inhibition and potatoes may be stored for up to 10-11 months after harvest. Chemical treatment controls sprouting efficiently for up to 7-8 months and then inten­ sive sprouting occurs with a consequent loss of quality. Unirradiated samples show sprouting within 5 months from harvest. (2) Irradiation and chemical treatment do not encourage rotting, provided the potatoes are handled gently during treatment and storage and that they are healthy at harvest. (3) Weight loss is higher in the chemically treated samples and the weight of edible tubers is higher in the irradiated samples. ITALIAN PROGRAMME 169

(4) Treatment by irradiation does not affect vitamin С and Niacin content as compared with chemically treated samples. (5) Irradiation, while inhibiting sprouting, reduces the hydrolysis of starches and keeps the sucrose and total sugar content low as compared with chemical treatment. (6) The total and soluble nitrogen contents are not affected by either trea tm en t. All these points clearly demonstrate that ionizing radiation, if used pro­ perly, is better able to preserve potatoes for long-term storage, than tradi­ tional methods based upon refrigeration and chemicals.

LEGISLATION ON THE TREATMENT BY RADIATION OF POTATOES, ONIONS AND GARLIC FOR SPROUT INHIBITION

The regulations cleared by the Ministry of Health (3 0 August 1973) and published in the Gazzettino Ufficiale No.254, 1 October 197 3 (see Appendix) allow the commercialization and the human consumption of some foodstuffs treated by radiation. These regulations are derived from law No.283 (30 April 1962) which states that the Ministry of Health may authorize for sale and consumption foodstuffs with added chemicals or specially treated, including with ionizing radiation. In fact, the industrial application of ionizing radiation to foodstuffs raises a series of considerations on the wholesomeness of irradiated foods, which is why irradiated foods have not yet been marketed. Through these regulations, Italy has authorized the marketing and consumption of potatoes, onions and garlic treated by gamma radiation to inhibit sprouting. - Among other points the regulations emphasize the observation of the following conditions: (a) The source of radiations should be exclusively 60Co or 137Cs. (b) The adsorbed radiation dose by the foodstuffs should not exceed 15 000 rads and not be less than 7 500 rads. (c) The irradiation process has to be carried out exclusively in the plants previously authorized, as stated in paragraph 55 of the DPR of 13 February 1964, No.185, and in any other disposition of the mentioned DPR. (d) CNEN has been delegated the control of the technical part and the protection aspects, while the health authorities verify the observation of the irradiation conditions. M oreover, the regulations specify packaging and labelling conditions and other indications related to marketing, sale and importation from foreign co u n tr ie s .

ECONOMIC AND TECHNOLOGICAL PROBLEMS

The economic and technological aspects are closely related because a technological problem has an economic response and vice versa. We know that, to reduce irradiation cost, several factors should be carefully considered. It is necessary not only to use the minimum effective dose, which is believed to be around 10 krad, a proper dose rate, considered to be in the range of 1 krad/min, a convenient type of container and a limited number of workers and technicians, but also the irradiation plant should be 170 BARALDI constructed as simply as possible and utilized all the year round through irradiating several products. Some of these products could even be plastic materials, irradiated for sterilization, which could be processed with the appropriate modification of the power source. The plant should be conveniently located so that it would be inserted into the existing foodstuff distribution and marketing lines, thereby avoiding further transportation costs. During the course of our technological experiments in potato sprout inhibition, after a series of trials using different types of containers and on the basis of the opinion of several people involved in the production, sale and industrial processing of potatoes, we came to the conclusion that the best approach to the industrial irradiation process (25 000-50 OOOtons/season) is the use of 1 XI X 1 m wooden pallet boxes during harvest, transport, irradiation and storage. Under these conditions, the potatoes are handled as little as possible and so periderm wounds are reduced, which is essential for successful long-term storage. Moreover, the use of this type of container reduces manpower, transportation and irradiation costs to a great extent. Finally, the pallet boxes allow improved storage conditions, because the potatoes are better aerated and at the same time protected from the weight of the upper layers. Under these conditions a 300-kCi plant is able to process 30 000 tons of potatoes in 90- 100 days (16 h/d) using two technicians as plant operators and four workers operating mechanical elevators at the loading a re a . The Casaccia Nuclear Center is at present carrying out experiments to extend the relatively short plant operating time spent on potato, onion and garlic sprout inhibition. It is hoped to extend the irradiation processing period up to 5-6 months after harvest. Besides considerations of processing cost reduction, other factors that may affect seriously the final result must also be considered. In this respect, a suitable variety should be selected for irradiation for long-term storage. Our experience shows that not all cultivars have the same response in terms of weight loss, rotting, sugar metabolism (a serous problem for industrial processing into potato chips and pommes frites) and colour of the pulp after cooking. M oreover, the health of the tubers at harvest in terms of virosis or mould and bacterial contamination, the absence of wounds at irradiation, an adequate interval between harvesting and irradiation, and the minimum handling before, during and after irradiation, which causes mechanical damage and physiological disease, should be seriously controlled. Finally, the use of a gentle means of transportation is suggested and control of the storage conditions (temperature, humidity and ventilation) is recommended.

PROSPECTS

Since the technological feasibility of potato sprout inhibition has been well established and the legal aspects (authorization for human consumption) have been cleared, the prospects for the immediate introduction of potato sprout inhibition by gamma irradiation in Italy are now of great importance. The great interest shown by producers' associations, traders and pro­ cessing industries (potato chips, precooked foods, fried potatoes etc.) in this new technology as an alternative for long-term storage has convinced ITALIAN PROGRAMME 171

Government authorities and industrial gamma-plant designers to consider seriously the installation of an industrial gamma plant, specifically designed for potato sprout inhibition, in the Fucino area (100 km East of Rome). This area is ideal for potato growing and storage. The average annual production is 150 000 tons and somewhat concentrated in the area, which also presents many storage facilities. Under these conditions the cost of transport from field to gamma plant to storage facilities is minimal. The project envisages the irradiation of one fifth to one sixth of the total production (25 000 - 30 000 tons), which could be stored to the end of May and then utilized during June, July and August, partly for industrial processing and partly for direct consumption. A second project will be completed this year (1974-7 5) with the purpose of defining marketing conditions and consumer reactions. The marketing test will provide information and data on consumer acceptability and economic evaluations on the distribution and transportation costs from the storage facilities to the markets. Irradiation and storage will again be carried out in large pallet boxes (1 m3) and distribution will be carried out in sacks (30 kg).

ACKNOWLEDGEMENTS

The author acknowledges the help and the advice given by Prof. A. Bozzini in promoting and organizing the Food Irradiation Programme at the Casaccia Nuclear Center.

APPENDIX

MINISTERIAL DECREE OF 30 AUGUST 1973 AUTHORIZING THE GAMMA IRRADIATION OF POTATO, ONION AND GARLIC FOR PURPOSES OF INHIBITION OF SPROUTING

THE MINISTER OF HEALTH

CONSIDERING Article 7 of Act No.283 of 30 April 1962 conferring powers to license the production and marketing of foodstuffs and beverages to or from which substances have been added or removed or which have undergone special treatments;

CONSIDERING Presidential Decree No.185 of 13 February 1964 relating to the safety of facilities and the protection of the health'of workers and the general public against ionizing radiation hazards accruing from the peaceful uses of nuclear energy;

HAVING CONSULTED the Higher Council of Health on the gamma irradiation of potato, onion and garlic for purposes of inhibiting sprouting;

HAVING CONSULTED the Ministry of Agriculture and Forestry;

HAVING CONSULTED the Higher Institute of Health;

HAVING CONSULTED the National Nuclear Energy Committee; 172 BARALDI

DECREES AS FOLLOWS:

A r t .l

It shall be permissible to possess, offer for sale or sell potato, onion and garlic which have been subjected to gamma irradiation for purposes of inhibition of sprouting.

A r t. 2

For the irradiation treatment referred to in the preceding Article, only- sealed sources of cobalt-60 or caesium -137 may be used. The radiation doses absorbed by the potato, onion and garlic may not be greater than 15 000 rads or less than 7 500 rads.

A r t. 3

The potato, onion and garlic referred to in Article 1 above may not be subjected to any chemical treatment, either before or after irradiation.

A r t. 4

Gamma irradiation of potato, onion and garlic for purposes of inhibition of sprouting shall be carried out exclusively in facilities previously licensed within the meaning and for the purposes of Article 55 of Presidential Decree No.185 of 13 February 1964, and shall be performed in accordance with all the other provisions, in so far as applicable, laid down in the Presidential Decree in question.

A r t. 5

Except for the powers granted under Presidential Decree No.185 of 13 February 1964 to the National Nuclear Energy Committee, the health authorities shall ensure that individual treatments conform to the conditions and lim its.laid down in Article 2 above. The Higher Institute of Health shall verify the validity and suitability of the dosimetric methods to be employed.

A rt. 6

Potato, onion and garlic subjected to gamma irradiation for the inhibition of sprouting shall be marketed and offered for sale in packaging closed by means of sealing or another tamper-proof procedure and bearing in a clear, indelible and unalterable manner a standardized marking from which the irradiation facility may be identified. Such marking shall be approved and reproduced in the licensing decree referred to in Article 4 above. In addition to complying with the provisions contained in Article 8 of Act. No.283 of 30 April 1962, the packaging shall bear the words "potato (or onion or garlic) irradiated for purposes of inhibition of sprouting" in clearly visible and indelible characters. ITALIAN PROGRAMME 173

A rt, 7

Imported potato, onion and garlic subjected to gamma irradiation for 'the inhibition of sprouting shall conform to the requirements of this Decree as regards both treatment and packaging.

Rome, 30 August 197 3

(signed) GUI Minister of Health

REFERENCES

[1] BELLI-DONINI, M .L ., BARALDI, D ., TAGGI, R., Relationship between peel damage and the accumu­ lation of terpene compounds in irradiated oranges, Radiat.Bot. 14 (1974) 810.

[2] BELLI-DONINI, M .L .. PANSOLLI, P., Irradiation gamma des raisins de table "H oanez", Food Irradiât. 10 (1970) 4.

[3] BARALDI, D ., Effect of gamma radiations on D-glucose present in apple juice, J.Food Sci. 38 (1973) 108.

[4] BARALDI, D ., Mono and b’idimensional separation of oxyacids by thin layer chromatography, J.Chromatog. 42 (1969) 125.

[5] MAGAUDDA, G ., Effetto d ell’irraggiamento gamma sulla conservazione del Clementino, Ind.Conserve (in press).

[6] INGHILESI, E., MAGAUDDA, G ., Effetti a livello microbiologico e tecnologico dell 'irraggiamento

gamma sulla conservazione di pomodoro S. Marzano, Sci. Tech. Alimenti 2 (1973) 91.

[7] BARALDI, D ., BELLI-DONINI, M .L ., GUERRIERI, G ., INGHILESI, E., MAGAUDDA, G .. MIUCCIO, C.F., Irraggiamento gamma di pomodori ,'Supermarmande,\ Noti. CNEN 5 (1973) 80. [8] BARALDI, D ., "Effect of gamma irradiation on carotenoid synthesis and colour development in tomatoes",

Proc.8th Int.Cong.Agrochimica, Venice 1 (1971) 556.

[9] BARALDI, D ., New solvent system in the chromatographic separation of pigments extracted from

tomatoes, Agrochim. 4-5 (1971) 371.

[10] BELLI-DONINI, M .L ., STORNAIUOLO, M .R ., Pectin changes in the ripening of irradiated and stored strawberries, J.Food Sci. 34 (1969) 509. [11] PANSOLLI, P., Radiation effects of pectinase solutions, Experientia 5 (1970) 499.

[12] BELLI-DONINI, M .L ., Relazione tra contenuto in ioni calcio e solubilizzazione delle sostanze pectiche

di fragole irradiate e conservate, Agrochim. 3-4 (1973) 370. [13] INGHILESI, E., PICCININO, G ., TIECCO, G ., CACIAPUOTI, R., Uso delle radiazioni gamma per la radicidazione di albume d'uovo essiccato, Sci.Tech.Alim enti (in press). [14] MAGAUDDA, G., The possibility of recognizing irradiated and non-irradiated potatoes by their weight loss, J.Food Sci. 38 (1973) 1253.

[15] BARALDI, D ., "Effect of gibberellic acid and kinetin on irradiated chemically treated and unirradiated potatoes. A possible method for identification of irradiated tubers", Identification of Irradiated Foodstuffs

(Proc.Coll. Karlsruhe, 1973), Rep.EUR-5126 (1974) 329.

[16] MAGAUDDA, G ., "Ulteriori esperimenti sul différente andamento della perdita in peso di materiale

vegetale irradiato", Identification of Irradiated Foodstuffs (Proc.Coll. Karlsruhe, 1973), Rep.EUR-5126 (1974) 337.

[17] MAGAUDDA, G ., "Evolution de la diminution en poids pendant la conservation : Approche pour

l'identification des fruits irradiés", Identification of Irradiated Foodstuffs (Proc.Coll. Luxembourg,

1970), Rep.EUR-4695 (1972) 141.

[18] EURISOTOP, Technologie de la radio-inhibition de la germination des pommes de terre, Cah.Inf. 44

( 1 9 7 1 ) . ^

[19] EURISOTOP, Technologie de la radio-inhibition de la germination des pommes de terre, Cah.Inf. 83

( 1 9 7 3 ) .

[20] BARALDI, D ., The gamma irradiation plant at the Casaccia Nuclear Centre, Radiat.Radioisotopi 1

( 1 9 7 1 ) 1 3 .

[21] BARALDI, D ., MIUCCIO, C .F ., GUERRIERI, G ., Metabolismo glucidico e contenuto in vitamina С e

PP in patate irradiate e trattate chimicamente, Agrochimica £(1971) 538. 174 ' BARALDI

[22] BARALDI, D ., GUERRIERI, G ., MIUCCIO, C .F ., Impiego delle radiazioni gamma per la inibizione

della germogliazione in patate, Ind. Conserve 4 (1971) 269. [23] BARALDI, D ., MIUCCIO, C .F ., Potato sprout inhibition by radiation and chemical treatment:

comparative studies on physiological and nutritional characteristics of the four major varieties in Italy,

J.Food Sci.-(in press). [24] BARALDI, D ., MIUCCIO, C .F ., Impego delle radiazioni ionizzanti per inibire la germogliazione delle

patate. Prove di fattibilita industriale e di trasformazione in patatine fritte, Radiat.Radioisotope

3 (1971) 3. [25] BARALDI, D ., Problemi relativi alia commercializzazione di derrate alimentan irradiate, Notiz.

CNEN 2 (1970) 41. PREPARATIONS FOR COMMERCIALIZATION OF IRRADIATED FOODS IN THE CZECHOSLOVAK SOCIALIST REPUBLIC

P. HORACEK Czechoslovak A tom ic Energy Commission, Prague, Czechoslovakia

The increasing importance of food preservation by irradiation is widely recognized as a result of the increasing objections to the use of various chemicals, especially chlorinated hydrocarbons. The toxicity of some of these chemical .compounds has been well established and is common know­ ledge but in spite of this, they are still being used. It is generally accepted that foods free of any additives are the most suitable for human consumption. Irradiation is one possibility of avoiding the use of food additives. A large amount of research activity in the field of food irradiation in the Czechoslovak Socialist Republic has been carried out since the sixties. In 1971 a special research project on food irradiation started studies on the effects of ionizing radiation on potatoes, mushrooms, meat, onions and wheat. Testing the wholesomeness of irradiated food is also involved. This project is supported by the Czechoslovak Atomic Energy Commission. I do not intend to go into details of the particular scientific experiments as it is not the task of our Panel and I shall concentrate only on those aspects that are important for the application of the irradiation process on an industrial level. Over the last few years our research institutes have verified the data published abroad. It has been confirmed that the most promising process for realization is the use of ionizing radiation to prevent sprouting and rotting of potatoes and onions and reducing losses caused by pests in stored grain. The technological feasibility of the irradiation process has been proved. Our health authorities have been asked for permission to irradiate potatoes, onions and wheat for human consumption. Clearance for'irradiation of potatoes with doses up to 10 krad has already been issued by the Ministry of Health of the Slovak Socialist Republic. We expect that there will be no problem in issuing clearances for all of the above-mentioned items since the Research Centre for Food Hygiene and Nutrition of the Ministry of Health has been carrying out tests on the wholesomeness of irradiated food items for many years. This institute has also been consulted on every problem that has arisen in the course of studies on food irradiation. In Czechoslovakia the most favourable situation is for the irradiation of' potatoes and onions. I assume that potatoes are especially suitable for the introduction of a large-scale commercial use of irradiation in Czechoslovakia for following reasons: (1) Low doses of irradiation are effective in saving potatoes from perishing through sprouting and rotting. Doses up to 10 krad have been accepted by the health authorities; (2) All potatoes that are allotted for human consumption from February till May have to be treated by chemical sprout inhibitors. Attempts to replace chemical treatment by irradiation are completely in line with the

175 176 HORACEK

present concern for environmental protection. As the health authorities are demanding a lessening or even avoidance of the use of chemical food additives, we hope to gain their backing for this project; (3) Due to the tremendous programme of house building realized by the Czechoslovak Government in recent years, many more inhabitants are living in modern houses, whichhave no facilities to store potatoes in the greater quantities that had been customary. Therefore it is necessary to supply the population with potatoes continuously over the whole year and large supplies of this agricultural product have to be stored by the distributors. For this reason the building of two irradiation facilities is being considered. Yet, the main objection against the irradiation method is its economy. To over­ come this obstacle the AEC has alotted funds for objective economic analyses of the proposed technology. The first study was carried out by M essrs. Jelen, Prouza and Zeman from the Institute of Research and Standardization of Fruit and Vegetables in Prague. Jelen presented their results at the symposium on food irradia­ tion held by the Council of Mutual Economic Assistance (CMEA) in Sofia in October 1973. The authors of the techno-economic study calculated the effectiveness of the irradiation plant in three alternative versions: (1) A 67 480 Ci 6QCo source (2) A 16 400 Ci 60Co source (3) A 91 100 Ci 137Cs source. A project to build in Prague a large warehouse with a capacity of 15 000 tons of potatoes has been considered. If an irradiation plant were set up in this warehouse building, there would be no extra transport costs to increase the price of the irradiation process. The first alternative has been shown to be the most effective. The authors based their analysis on 500 hours operating time per month. The following quantities have been considered: 15 000 tons of potatoes, 14 000 tons of onions, 2 50 tons of mushrooms, 100 tons of strawberries and 115 tons of medical products during one year. The following effects are expected: (1) Potato losses should fall to one third; chemical sprout inhibiting compounds would be saved; the quality of potatoes in the market would be im p ro v e d ; (2) Onion losses during storage should decrease from 13% to 8%; coupled with an improvement in the average quality; (3) The prolongation of the shelf-life of strawberries should allow their sale in higher quality classes. Table I shows the expected cost of irradiation for the various items and Table II shows the assumed utilization for the irradiation facility. ' The sterilization of medical products has been also considered but this has been .criticized as unrealistic. We have not learnt of any irradiation plant where the dose can be changed over more than two orders (potato irradiation requires 10 krad and the sterilization of medical products .2. 5 Mrad). Of course, the energy utilization factor is of great importance for the economy of the process. On the other hand, the annual operating time of the irradiation facility is also of great economic importance. A com pro­ mise should be found between those two demands. It would be very interesting to learn whether any attempts have been made in this direction. If it should prove impossible to find another complementary programme instead of medical product sterilization, the economic indexes will deteriorate, though not to such an extent that the whole project would be jeopardized.

/ CZECHOSLOVAK PREPARATIONS 177

TABLE I. COST OF IRRADIATION OF FOOD ITEMS

Czech crowns Percentage of average

per kg p r ic e

P o ta to e s 0 . 0 3 4 4 . 3

O n io n s 0 . 0 2 3 0 . 7

Strawberies 0 . 8 6 7 . 2

M u sh ro o m s 0 . 6 9 3 . 4

TABLE II. UTILIZATION OF THE IRRADIATION FACILITY (PERCENTAGE PER MONTH)

P o ta to e s O n ion s M u sh ro o m s Strawberries Sterilization

January 7 0 3 0 - - -

F ebruary 4 8 52 - - -

M a rch - - - - 1 0 0

A p r il - - 1 9 - 8 1

M a y - - 1 9 - 8 1

June - ■ - 1 9 2 1 6 0

July - - 1 9 2 1 6 0

A u g u st - - 1 9 - 8 1

S e p te m b e r - 1 9 - - 8 1

O c to b er 5 0 5 0 - - -

N o v e m b e r 5 0 5 0 - - -

D e c e m b e r 7 0 3 0 - - -

I shall not deal with the problem of large-scale wheat irradiation in detail. The situation is more complicated as some kinds of insects are somewhat resistant to ionizing radiation and doses that had been previously thought to be lethal now appear to cause only sterility. .According to the feeding tests with wheat irradiated with 50 krad carried out by Prof. Wolf and his colleagues in the Research Centre for Food Hygiene and Nutrition, changes have been found in the blood count of experimental animals. The other 'disadvantage' of grain irradiation is the fact that there is no demand to irradiate the whole crop, but only those parts that contaminated by pests. Nevertheless, we consider it reasonable to continue the experimental programme in this field. Work on studies for the construction of the experimental grain irradiation plant were expected to commence in 1974. We expect to use an electron accelera­ tor of an output 1. 2 kW and an electron energy of 4-5 MeV as irradiation source. This accelerator has been developed in the Prague Research Institute of Vacuum Electrotechnics. 178 h o r a C e k

To conclude, I should like to summarize the situation of the com m er­ cialization of food irradiation processes in our country. The AEC is of the opinion that it is necessary to prove the technology and economics of food irradiation in pilot-plant experiments. In the first place, these experiments should concern those foods for which a permission for irradiation has been granted by the health authorities. At the present time the Czechoslovak health authorities are expected to permit the irradiation of potatoes with 10 krad, onions with 10 krad and grain with 30 krad. Our health authorities insist on making their- own experiments, which have been included on the above-mentioned products. On the basis of preliminary results, it is expected that the irradiation of mushrooms with up to 200 krad will be permitted in the near future. The economic concept of potato and onion irradiation will be further corrected and we shall continue to study grain irradiation. Should the results be favourable, we shall encourage the building of pilot irradiation plants. These plants should supply definite data for the design of industrial facilities. We presume that an experimental plant for potato and onion irradiation will be built during the sixth five-year plan, i. e. during the period 1976 - 1980. STATUS OF THE FOOD IRRADIATION PROGRAMME IN ISRAEL

М . LAPIDOT Soreq Nuclear Research Centre, Yavne, Israel

Marketing tests of irradiated potatoes and onions, of the order of tens of tons in 1968/69 and of the order of hundreds of tons in 1969/70, have been successfully completed, indicating very good consumer acceptance. An economic feasibility study followed that considered a large-scale irradiation and storage complex, based on offers from some leading irradiation plant manufacturers. The results indicated that the venture be economically feasible if at least one and a half months' consumption of potatoes (~ 10 000 tons) and onions (~ 2500 tons) were irradiated. Although these were feasible amounts, representing the consumption in the critical periods (September — October for potatoes and March — April for onions), the Ministry of Agriculture and the Vegetable Marketing Board decided to go ahead with the project only after larger-scale test marketing had been performed. The irradiation of the corresponding amounts of the order of thousands of tons was, obviously, not economic under local conditions in an industrial- scale plant. Hence attempts were centred on obtaining a pilot-scale facility. Such a facility was finally secured in the USA, the USAEC loaning its Mobile Gamma Irradiator for the purpose. A 3-year programme to start with 500 tons of potatoes, 100 tons of onions, and 100 tons of poultry feed in the first year, and reaching 1500 tons of potatoes, 2000 tons of onions and 300 tons of poultry feed in the third year was approved by the responsible authorities, to be funded jointly by the Ministry of Agriculture, the Vegetable Marketing Board, the Israel AEC and the National Council for Research and Development. This programme is conditional on the commissioning of the Mobile Gamma Irradiator, and this is being studied at the present. It is hoped that poultry-feed irradiation will start in 1974, to be followed by potatoes and onions in significant amounts in 197 5. It is also hoped that with the unit available a local manufacturer of food products will use it several months each year for irradiation and test marketing of wheat products, a clearance being expected in 1974. A joint Ministry of Agriculture-AEC steering committee has been appointed in 197 3 to consider all food irradiation projects performed in the country and has been provided with a modest research fund to support these projects. These projects were continued in 1974, the committee being now joined by a representative of the NCRD. The items now covered are stimulation of seeds and plantlets, mutations in citrus and other fruits, shelf-life extension of mushrooms, surface pasteur­ ization of citrus fruit, and stored-product insect sterilization and eradication. Further items to be added may be strawberries and garlic (in 1974/75), which had been successfully treated until 1968/69 but which had not been studied further pending clearances (which have now been given in Italy and in the Netherlands). Limited quantities of spices may also be irradiated on the basis of the existence of a clearance abroad. Petitions on these items should be submitted in 1974 and 1975.

179

POSSIBILITIES AND PROBLEMS OF INTRODUCING RADIATION PRESERVATION OF FOODSTUFFS IN URUGUAY*

F .G . MERINO National Atom ic Energy Commission, Montevideo, Uruguay

GENERAL

The work done in Uruguay has been concentrated on the inhibition of sprouting in potatoes by means of gamma irradiation. The National Atomic Energy Commission has been carrying out a multi-stage programme since 1972. Experiments aimed at inhibiting sprouting in onions and at disinfestation of wheat were started in 1974, but since these experiments are relatively recent, the present summary relates only to potatoes.

I. TECHNICAL FEASIBILITY

In 1973 we carried out technological tests on a pilot scale with five tons of potatoes (in collaboration with the Argentine National Atomic Energy Commission) and obtained positive results [1]. The appearance, taste and wholesomeness of potatoes exposed to 8.6 krad were comparable to those of potatoes imported from abroad in times of shortage to supply the local m a rk et. The control potatoes lost their com m ercial value in the seventh month after harvesting, while the irradiated potatoes lasted a month longer, v.the losses being about 17% in one batch and about 27% in the other. This difference was due to attack by microorganisms such as Fusarium, which in fact represented the greatest difficulty to obtaining better results. To treat 30 000 tons a year — the average requirement for Uruguay to be self-sufficient — in a potato irradiation facility, a strict watch would have to be kept on the wholesomeness of the potatoes. Some Uruguayan technicians have expressed doubts about the possibility of obtaining healthy potatoes in such amounts in this country. Another obvious disadvantage of irradiation is that the potatoes are rendered more sensitive to attack by microorganisms than unirradiated p ota toes.

II. LEGAL AUTHORIZATION

Authorization has already been obtained from the Montevideo Municipality [2] and negotiations for obtaining an authorization at the national level are well advanced.

* Written statement distributed in the absence of the author.

181 182 MERINO

III. ECONOMIC FEASIBILITY

We have carried out a study on the economic feasibility and have obtained positive results [2]. By establishing a food-irradiation facility that could be 1

used to inhibit sprouting in potatoes, the country could become self-sufficient j and eliminate potato imports now valued at about $3 million.

IV. PLANS OF ACTION

1974 — Investment project and public acceptability test with 30 tons of potato. 1975 — Invitation for tenders for the construction of a facility for radiation preservation of foodstuffs.

V. CONCLUSIONS

Uruguayan experience indicates that 30 000 tons of potatoes would have to be marketed efficiently each year; if this could not be ensured, the project would not be economically viable. The handling of such large volumes of potatoes will, m oreover, create problems to which definitive solutions have not yet been found. The facility should be versatile in design to keep idle time to a minimum. In addition to the treatment of potatoes, which will account for four months of the year, other uses of the facility are being considered: (a) Inhibition of sprouting in onions ' ' (b) Technological studies on disinfestation of wheat in small volumes with a view to introducing this technique for the preservation of cereals at a later date (c) Commercial sterilization of medical products, with a view to improving the econom ics of the facility and providing a dynamic factor in the development of the market and of related industries.

REFERENCES

[1] ORTIZ, P., et al.. Irradiación de papas. Pruebas tecnológicas a escala piloto, CNEA (Uruguay) CNEA (Argentina) (Irradiation of potatoes. Technological tests on a pilot scale by the Uruguayan and the

Argentine National Atomic Energy Commission), Buenos Aires (in press).

[2] MERINO, F .G ., Estudio de Factibilidad Económica para una Planta de Conservación de Alimentos

(Economic feasibility study of a facility for the preservation of foodstuffs), Montevideo (1972). STATUS OF POTATO IRRADIATION IN FRANCE

F. SANDRET Ecole Nationale Supérieure des Industries Agricoles et Alimentaires, CERDIA, Massy, France

From the statutory point of view, the conditions governing the irradiation and subsequent marketing of foodstuffs, beverages and commodities capable of being used for human or animal consumption were defined by a decree of 8 M ay 197 0. Within the framework of this decree, an order of 8 November 197 2 authorized the irradiation and marketing of potato tubers. The procedures that led to this authorization and the principal statutory arrangements adopted are collated in issue No.2 (September 1973) of the review "Informations sur l'irradiation des denrées" (POMAROLA, М., SANDRET, F., Marketing of irradiated potatoes — the implications of the authorization issued in France) (text in French). Provision is also made for the lodging, in the fairly near future, of applications for authorization for the following: inhibition of sprouting in onions, garlic and shallots; sterilization of spices, maize starch, and 'germ- free' animal fodder. What developments are to be expected from the marketing point of view in the case of irradiated potatoes, this being the only food product at present authorized for sale? It has to be admitted that the present situation in France is not very favourable. The total annual production of potatoes is estimated to be about 8-10 million tons, of which 50% is probably used directly without processing for domestic consumption (80 kg per head per year) and 6- 8% is devoted to industrial uses or is processed (potato-starch, chips, dried potato, etc.). Whereas the bulk of the crop that meets the demands of the domestic market and processing industries is gathered in the autumn (September and October) in the major producing regions, various favoured regions (the South and Britanny) provide 'new' potatoes from M arch-April, and some early varieties, produced under normal conditions, arrive on the market at the end of June or the beginning of July. Except in an abnormal year, the domestic demand can thus always be met and the quality is generally satisfactory. Although sprouting inhibitors (IPC-CIPC are practically the only ones used) are not officially authorized, their use is 'tolerated' by the health authorities. Hence, large producers, wholesalers and industrial users, whose silos and depots are mostly situated in the North of France, can keep potatoes in good condition up to thé end of April and fairly good condition until June, at which time the normal crop of sufficiently ripe early potatoes becomes a v a ila b le . This being so, and as long as the public remains more sensitive to the idea of an 'irradiated product' than to the pollution of the environment and

183 184 SANDRET the food chain by the chemical products used as sprouting inhibitors, it is to be feared that the demand for techniques involving the action of ionizing radiations will remain very slight. However, the authorization granted in 1972 allowed some work to be carried out on very limited amounts (about ten tons), the purpose of which is as follows: (1) To familiarize possible consumers and users with the concept of a 'product treated with ionizing radiations' (2) To define more accurately than was possible with the necessarily incomplete tests previously performed the fields in which this technique could be employed in the first instance: tubers for use by industry at the end of a season, food potatoes for consumption in hot climates, etc. This work is being carried out by the following bodies: (a) The "Société Conservatome", utilizing the facilities at its Dagneux centre (1 100 000 Ci from 60Co unit installed; 1 000 000 forecast for 1974) or its mobile IRMA (131Cs) irradiator. (b) The Centre for Applications of Ionizing Radiations (CAPRI) of the French Commissariat à l'énergie atomique. These facilities taken together will make it possible to treat several hundred tons of potatoes per season, should the occasion arise. POTATO AND ONION IRRADIATION IN THE NETHERLANDS

H. SPA REN BERG Institute for Storage and Processing of Agricultural Produce - IBVL, Wageningen, The Netherlands

1. GENERAL VIEW

The acreage under potatoes in the Netherlands amounts to 23% of the total area of field crops (approx. 160 000 ha). Well over half (58%) is devoted to varieties for consumption, the remaining 42% being occupied by production for the starch factories. The final destination of the total production of potatoes, approx. 5 million tons converted into percentages, gives the following picture:

Home consumption of ware potatoes 19% Exports of ware potatoes 12% Home use of seed potatoes 7% Exports of seed potatoes 6% Processing industry 5% Starch industry 36% Stock feed and waste 15%

The storage capacity with modern air-cooled systems is entirely used for the seed potatoes and for main-crop ware potatoes. Neither the first earlies nor the industrial potatoes are stored in such storage buildings. The total storage capacity is more than if million tons. Exports of ware and seed potatoes are nearly 1 million tons. The consumption of fresh potato products per caput in the Netherlands in kilograms is as follows:

Fresh potatoes Potato products Total

1964 ' 89 6 95 1967 80 10 90 1969 76 12 88 19 70 72 13 85 1971 71 14 ' 85 1972 68 15 83

2. STORAGE OF POTATOES

Because there is only one potato harvest per year, a proportion of the potatoes must be stored from September/October until the following May/ June, i.e. for a period of some 7-9 months. Increasingly, special potato stores are being constructed for this purpose, using external air cooling.

185 186 SPARENBERG

Cold storage is necessary because at low temperatures (2-4°C) potatoes do not sprout, lose less moisture and retain good keeping qualities. In practice, however, it has been found that at such low temperatures potatoes eventually sweeten, in which case they are no longer suitable, for example, for crisping or chipping. For these reasons preference is given to storage at somewhat higher temperatures, 5-7°C for consumption purposes and 8-12°C for potatoes intended for the crisp and chip industry. Seed-potatoes are always stored at 2-4°C. A consequence of the higher storage temperature for ware potatoes is that the potatoes sprout and cease to be usable after a very short time. ' To counteract this sprouting, the potatoes are treated with chemical sprout inhibitors. Widespread use is made of powder or liquid with the active substances IPC and/or CIPC. The powdered IPC/CIPC agents, which generally contain 1% active constituent, are applied to the potatoes immedi­ ately they are placed in the store, 1 kg of powder being used for 1000 kg o f p o ta toes (10 ppm ). Whilst featuring generally good sprout suppression with a single application, however, powder inhibitors also have disadvantages; (a) If the tubers are wet or insufficiently corked, a skin irritation (burn) often occurs. This is not only a surface blemish, but also has the consequence that peeling losses are greater. (b) When the bins are emptied there is often a troublesome formation o f dust. The liquid compounds are being used more and more. These are applied by means of special equipment via the ventilating system of the storehouse. The liquid compounds contain 25-30% active agent, for the greater part CIPC. The sprout-inhibiting effect is less than of powder and therefore a higher dose has to be applied. The maximum permissible quantity is 20 ppm. Since liquid compounds are applied via the fan, the potatoes can be treated after the lot has been blown through and well-suberized. As a result skin irritation hardly occurs if at all. A residue is left in the potato after treatment with IPC/CIPC. In Holland the residue in the peeled tuber should not exceed 0. 5 ppm. At the dose mentioned this maximum will generally not be exceeded. Treatment of potatoes with IPC/CIPC is not expensive and, moreover, it is simple to apply. The costs amount to approx. Hfl. 1 to Hfl. 1. 50 per ton of potatoes.

3. IRRADIATION OF POTATOES

Irradiation is a non-chemical method of sprout inhibition in potatoes. From experiments carried out with 4 varieties, Bintje, Eigenheimer, Libertas and Furore, applying gamma and beta rays, it appeared that: 10 krad gamma rays provide excellent sprout inhibition over the entire s e a s o n (8 m onths) 7. 5 krad is ample for Bintje and Eigenheimer, but somewhat on the low side for Libertas and Furore 20 krad beta rays or electron irradiation appears to be sufficient for 3 out of the 4 varieties. For varieties with deep eyes, such as Eigenheimer, the penetration of electron rays is too low. POTATOES IN THE NETHERLANDS 187

Since beta rays have less penetration than gamma rays, this means that the tubers have to be turned when applying beta rays. Theoretically this is quite possible, but in practice there are still a great many technical difficulties to overcome. One of the main problems is mechanical damage caused by rolling over within the irradiation area. This was the reason why gamma irradiation was used as a starting point in a study carried out by IBVL and ITAL in 1971 and 1972. Gamma rays have high penetration, permitting the irradiation of a layer of potatoes of a particular thickness. It has been found that the maximum layer thickness with irradiation from two sides is 80 cm, in view of the ratio of the maximum to the minimum radiation dose (Dmax/Dmin), \yhich must not exceed 2. This means in practice that if the potatoes are irradiated in containers (boxes), one of the dimensions of the containers must not exceed 80 cm. To obtain a reasonable potato capacity, e. g. 1000 kg, it appears preferable, on grounds of container stability, to have a substantial area combined with a height of 80 cm (e. g. 1.20 x 1. 60 x 0. 80 m ). A low radiation dose inhibits division of the meristematic tissue. However, the inability or reduced ability of cells to divide has consequences for the practical irradiation of potatoes. If potatoes are liable to be damaged before irradiation by some necessary preliminary treatment, e.g. sorting, transport or tipping into boxes or in bulk, they must be left for a while to permit wound healing (corking). If irradiation is performed immediately after such preliminary treatment, wound healing can be prevented or impeded and the vulnerable surface tissue forms a convenient means of access for microorganisms. A well-known- example is the increased susceptibility of potatoes with poorly healed wounds to Fusarium.

4. METHODS OF IRRADIATING POTATOES

In principle there are two methods of irradiating potatoes: (a) the potatoes are carried in containers along the irradiating source, or (b) the potatoes are carried along the source on conveyor belts. For our experiment the first possibility was preferred since with conveyor belts both the efficiency and the capacity of the irradiating process suffer. To improve this a complicated system of conveyor belts would be required within the irradiation room, with the attendant risk of damage to the potatoes. Moreover, the distance from storehouse to source and back is very long and would require repeated changing from one belt to another with once more the likelihood of damage. Apart from this, the system would be very expensive and complicated. The method that presents the minimum of risk of damage is irradiation in boxes. The potatoes can be harvested directly into the boxes, in w hich they can, if necessary, be blown dry, providing a curing period of approxi­ mately 2 weeks. Following this period the potatoes can be irradiated in the boxes, which are then returned to the storehouse. The potatoes remain in the boxes before, during and after irradiation. As will appear from calcula­ tions later on, this is a very expensive method. The period of dormancy, which runs from 6-8 weeks after harvest, would appear to be the most favourable for irradiation. It is assumed that for irradiation a period of approximately 10 weeks is available (October to mid D e ce m b e r ). 188 SPARENBERG

In view of the high costs associated with storage in boxes, the question arises whether storage in bulk is possible as well. The sequence then applied would be: acceptance of the harvested crop; storage in bulk; curing period/drying; irradiation in boxes; storage in bulk. The problem here is again to avoid damage as much as possible, which can occur when filling and unloading the boxes again after irradiation. An important aspect is the quality of the irradiated potatoes and in particular the tendency to grey discoloration after boiling. This subject is discussed further in section 6.

5. COMPARATIVE STUDY

We started from: An irradiation period of 2-2| months immediately after harvest Irradiation with gamma-rays from a 60Co gamma source An irradiation and storage capacity of 20 000 tons potatoes. The following types of plants were compared:

Plant I: harvest - reception - storage in bulk - IPC treatment (usual type). Plant II: harvest - reception - pre-grading in 3 sizes (< 35, 35/55 and > 55 mm) - storage grading size 35/55 mm in boxes (the other 2 sizes in bulk) - irradiation in boxes - storage in boxes. Potatoes in bulk are treated with IPC (pre-grading is intended to restrict the number of boxes). Plant III: harvest - reception - storage in bulk - irradiation in boxes - after irradiation loading in bulk.

TABLE I. CAPITAL COST, IN THOUSANDS OF GUILDERS

Build ings Reception, Per ton Plant Radiation (including transport, T o ta l of type source ventilation) miscellaneous potatoes

I 4400 550 - 4950 0.247

II 6100 2645 869 9614 0.480

III 4900 945 903 6748 0.337

TABLE II. OPERATING COST, IN THOUSANDS OF GUILDERS

Building, Plant Radiation Per ton of reception, T otal type source potatoes transport

I 821 - 821 0.041

II 1574 260 1834 0.092

III 1008 275 1283 0.064 POTATOES IN THE NETHERLANDS 189

The capital and operating costs were calculated in 1971/72 for these three types of plants. Tables I and II show principal figures. The costs are highest in case of plant II. This is mainly a result of the high costs connected with the use of boxes. It appears that in type III operating the costs are approximately Hfl. 2 3 more per ton of potatoes than for the usual type I (no irradiation - chemical sprout-inhibitor). It should be possible, however, to store in bulk before and after irradiation to meet the require­ ment of incurring the least possible damage to the potatoes.

6. COOKING QUALITY

Storage tests with gamma-irradiated potatoes in the season 1969/70 showed that after cooking grey discoloration occurred in many cases unlike comparable potatoes treated with IPC/CIPC. The same phenomenon is also mentioned in American experiments. It was therefore considered desirable to test Dutch potatoes on a much wider scale than in the past with respect to this phenomenon. In both 1970-1971 and 1971-1972 various tests were carried out in which potatoes from various origins and of different varieties were cooked monthly after irradiation or IPC/CIPC treatment and during which the discoloration was determined 0, f-, 1 and 24 hours after cooking. The potatoes used in these tests had been stored in a storehouse so that storage conditions were identical for both irradiated potatoes and those treated with IPC/CIPC. The storage temperature was 8-12°C. The dis­ coloration - greyish to green - was registered by means of figures, in order to reproduce the results even more clearly. The scale was as follows: 0 = no 1 = slig h t 2 = moderate 3 = strong discoloration.

TABLE III. DISCOLORATION AFTER COOKING

Total (see text)

Dec. Jan. Feb. March A p ril May June

1970/71

4 lots Bintje: gamma 6 .5 27.0 11.0 21.5 21.5 22.5 19.5 IPC powder 1 1.0 8.5 1.5 6 .5 6 .5 4 .5 2.0

1971/72

4 lots Bintje: gamma 7.5 12.5 20.0 30.0 31.0 31.5 - IPC powder 0 1.0 4 .0 5.0 5.0 10.5 -

14 lots Bintje : gamma 65.0 83.5 94.0 112.0 123.0 114.5 - IPC powder 16.0 23.0 37.0 4 8.5 37.5 44.5 -

10 varieties, clay: gamma 66.0 88.0 103.5 97.5 98.0 99. 0 - IPC 28.5 48.5 57.5 59.5 62.0 59.0 -

10 varieties, sand: gamma 62.0 79.0 88.0 85.5 89.5 90.0 - IPC 2 5.5 42.0 54.0 63.0 58.5 53. 0 - 190 SPA REN BERG

It would go too far to give all figures of the tests here and it will suffice to give survey tables of the total discoloration per month. This implies that, e. g ., in a test with 4 lots of irradiated Bintje potatoes, per cooking date, the figure given in the table is the sum from the 4 lots of the figures 0, I, 1 and 24 h after cooking. Such a figure in the example can reach a maximum of 48, namely 4 (lots) x 4 (date of assessment) x 3 (figure for strong discoloration). These results are given in Table III. For more detailed data we refer to IBVL bulletins (1970/71 and 71/72). We can draw the following conclusions from the experiment: (1) Gamma-irradiated potatoes of different varieties and lots show a much stronger and more rapid darkening than comparable potatoes treated with IPC/CIPC. (2) The grey discoloration increases as the storage season progresses; this also applies, although to a much lesser extent, to chemically treated potatoes. If the criterion applied allows slight discoloration (1), it appears that for irradiated potatoes of the Bintje variety this criterion is already exceeded after December. This is not the case for non-irradiated potatoes throughout the entire storage se a so n . (3) Some varieties and lots show more discoloration than others. (4) The darkening, especially in case of the Bintje variety, is considered undesirable in practice; this discoloration, however, cannot always be avoided later in the storage season, not even with chemically treated potatoes.

TABLE IV. DISCOLORATION (1972/73)

T o ta.1 Sample D ec. Feb. March June

4 lots B intje: beta 15.5 17.0 15.5 18.5 IPC powder 1.0 2.0 ' 1.5 5.5

9 varieties, clay: beta 61.5 60.5 53.0 60.0 powder 12.5 21.0 .1 2 .5 19.5

9 varieties, sand : beta 62.5 51.0 57.5 69.0 powder 21.0 17.5 23.5 25. 0

This disappointing result as regards the darkening of irradiated potatoes is one of the reasons why in Holland we are still very reluctant to apply - irradiation in practice. ■ Since beta and electron rays penetrate the tissue less deeply, an experi­ ment has now been started on the cooking discoloration of potatoes irradiated with electrons. A preliminary test in 1972/73 has shown that the discolora­ tion is less than in the case of gamma irradiation (Table IV). The investigation is being continued and is also partly financed by the IAEA. POTATOES IN THE NETHERLANDS 191

7. FRYING QUALITY

In both 1971 and 1973 in the processing industry irradiated Saturna potatoes were fried into chips and irradiated Bintje potatoes were processed into par-fries at the following 4 times: January, March, May and July. For comparison purposes potatoes of the same lot were used that had been stored in the same storehouse, but treated with IPC/CIPC powder. In July this practice test showed a strong increase in brown discoloration when processing chips from irradiated potatoes. Apart from this test, small- scale experiments were carried out in both years with four lots of Saturna potatoes, from which the 2 items - irradiated and chemically treated - were sampled monthly and samples fried into chips. The chip colour was assessed in accordance with IBVL colour scale. Table V gives a survey of the chip colour figures of these tests. From the table it appears that up to 2-3 months after irradiation the chip colour is mostly j -1 point lower than for chemically treated potatoes; after that the same level was reached. Unlike 1971, we found a strong decrease in chip colour in the irradiated samples in the month of June 1972 (a difference of 2-4 points).

TABLE V. SURVEY OF CHIP COLOUR FIGURES* FOR IRRADIATED AND IPC/CIPC-TREATED SATURNA POTATOES

Sample D ec. Jan. Feb. March A p ril May June

1970/71

Sat. 1: gamma 5 6- 5* 6 6 7 7 Sat. 1: powder 7 7 6± 8 7 7 7- Sat. 3 : gamma 5 7 7 7 6 7 6 Sat. 3 : powder 6 7 7 7 6 6 7 Sat. 5: gamma 6 7 6 6 7 7 6- Sat. 5: powder 7 ■ 8- 7 7 7 6 6- Sat. 7: gamma 7 8- 5 i 7 7 6 6 Sat. 7: powder 6 8 7 8 7 7 6- Sat. 1,3, 5,7 ¡gamma 23 28 24 26 26 27 25 Sat. 1 ,3, 5, 7 : powder 26 30 2 7 i 30 27 26 26

1971/72

Sat. 1: gamma 5 6 6 7 7 7 6 Sat. 1: powder 7 8 7 7- 7 8 7 Sat. 3: gamma 5 5 6 5 6 7 4 Sat. 3 : powder 6- 6 6- 6 5 5 8- Sat. 5: gamma 6 5 6 5 7- 7 5 Sat. 5: powder 5 6 6 6- 6 7 7 Sat. 7: gamma 4 5 6- 6 6 6- 3 Sat. 7 : powder 6 5 6 6 7- 6 7- Sat. 1,3, 5, 7: gamma 20 21 24 23 26 27 18 Sat. 1,3, 5,7 : powder 24 25 25 25 25 26 29

a IBVL-scale: 0 = very dark colour; 10 = light yellow. 192 SPARENBERG

Summarizing, we can make the following conclusion as regards frying quality:

Chips: for the first 2-3 months after irradiation the chips have too dark a colour; later on their colour is good and at the same level as the chemically treated potatoes. At the end of the season (June/July) the chip colour of the irradiated potatoes may deteriorate sharply to an unacceptable level. Pommes frites: a grey discoloration of the potato strips was always found when frying irradiated potatoes. The same phenomenon occurs as after cooking. The product becomes unsaleable.

In 19 72/73 preliminary tests were also made with processing chips and pommes frites from electron-irradiated potatoes. The provisional conclusion is that there is no, or only a slight occurrence of discoloration in pommes frites. This investigation is also being continued.

8. Fusarium INFECTION

It is known that the low dose (approx. 8-10 krad) used for potato irradiation inhibits development of the meristem tissue and so sprout formation no longer, or hardly occurs over a prolonged period. The reduced capacity of cell division, however, also has an affect on the suberization of damage. Wound healing is virtually suppressed and a greater susceptibility to Fusarium may be the result. In our tests to check Fusarium infection in irradiated potatoes, we applied the following method: The potatoes destined for these tests are stored after lifting in air-cooled rooms and eventually dried by means of air ventilation. After a wound-healing and suberization period of 2-3 weeks at 10-15°C, the number of 20-kg containers from the Pilot Plant for Food

TABLE VI. Fusarium INFECTION IN 1968-1972

G a m m a Powder IPC/CIPC

Tubers Tubers

Sample Infected with Infected with No. Fusarium No, Fusarium examined examined No. % No. %

Bintje

Field crop 4766 81 1.7 4622 38 0.8 Graded 4943 52 1.1 4830 26 0.5 T o ta l 9709 133 1.4 9452 64 0.7

Saturna

Field crop 7796 277 3.6 7422 132 1.8 Graded 6448 219 3 .4 6402 207 3 .2 T o ta l 14244 496 3.5 13824 339 2 .5 POTATOES IN THE NETHERLANDS 193

TABLE VII. Fusarium INFECTION OF POTATOES IN 20-kg CONTAINERS AND IN 1 -m 3 BOXES IMMEDIATELY AFTER IRRADIATION

% Fusarium Sample 1 -m 3 box 20- kg container

1970-1971

Bintje 2 1.6 0.4 Bintje 4 1.6 0.2 Bintje 6 6.4 5.2 Bintje 8 1.6 1.1

1971-1972

Bintje 2 4 .3 0 Bintje 4 14.3 5 .1 Bintje 6 4.7 1.1 Bintje 8 2 .8 0 .9 _

Irradiation required for the experiment were filled with field-crop and graded potatoes. The potatoes destined for irradiation were transported the same week to the Pilot Plant, where they, were to be stored for 4 weeks, applying mechanical cooling at 6-10°C, before irradiation took place. The potatoes thus had an opportunity to recover from any damage in­ curred when grading, filling the 20-kg containers and during transport. Immediately after irradiation, the potatoes were brought into air-cooled bins (storage temperature 7-10°C) for final storage, in which also the IPC/CIPC treated potatoes of the same lot were stored so that storage conditions were identical for both samples. Table VI gives a survey of the Fusarium infection in the varieties Bintje and Saturna tested in 1968-1972. In both 1971 and 1972 4 lots of Bintje were checked for Fusarium infec­ tion after grading the irradiated potatoes in 1-m 3 boxes. The pretreatment was the same as in the tests described above. After irradiation, however, the potatoes were carried by conveyor-belt into 1-m 3 boxes covered inside with foam-rubber to break the fall. The boxes were stored at 8-12°C in a box storehouse and the potatoes examined for Fusarium infection in the beginning of June. Table VII gives the percentages found, compared to those found in the previously mentioned tests in which the potatoes were stored in 20-k g containers. The following conclusions were drawn from this investigation: (1). In both Bintje and Saturna potatoes the percentage of Fusarium- infected tubers was clearly higher among the irradiated potatoes than among the chemically treated potatoes, despite the precautions against damage taken for the irradiated potatoes. (2) Saturna appears to be a lot more susceptible to Fusarium than Bintje, which is quite well known in practice. (3) If the potatoes are loaded into 1-m 3 boxes after irradiation, the percentage of Fusarium-infected tubers may increase sharply. 194 SPARËNBERG

(4) In practice this means that, when storing potatoes in boxes after lifting, irradiation may only be applied after a certain curing period (the potatoes remain in the boxes during irradiation). The capital and operating costs of such box-storage are extremely high and not recommendable from an economic point of view.

9. LEGAL ASPECTS OF THE APPROVAL OF IRRADIATED POTATOES

To control the marketing of irradiated potatoes it is necessary for the government to issue guidelines on the production, storage and distribution of these products. It has not so far been possible to identify irradiated potatoes after irradiation, owing to the lack of a rapid specific method of detection. For potatoes this has hitherto meant that approval is subject to the following conditions: (a) Potatoes already treated with chemical sprout inhibitors must not be irradiated. (b) Wholesale packs of irradiated potatoes must be marked with a clearly legible notice reading: "Irradiated potatoes (for prevention of sprouting) -.do not treat with chemical sprout inhibitors". Retail packs must be marked with a clearly legible notice reading: "Irradiated potatoes (for prevention of sprouting)" and the (irradiation) symbol. In the Netherlands potatoes have received unrestricted approval, provisionally for a five-year period starting from 23 March 1970.

10. CONSUMER ACCEPTANCE

If the trade is to carry out large-scale irradiation of potatoes, they must be accepted by the consumer. In general, it can be said that this acceptance, as well as the associated launching, is proving laborious. This is presumably not unconnected with the history of radiation as an alternative to chemical treatment; it is regarded by the uninformed consumer as, at best, an extension of medical irradiation. For this reason it would be necessary to mount an intensive campaign of education before any product can success­ fully be launched. All this, of course, assumes that it is compulsory for the fact of irradiation to be mentioned on the label. This is automatically advocated in the Netherlands since free consumer choice is regarded as being of prime importance and also in order to avoid problems with exports to countries where irradiation has not yet been approved. It is clear from test marketing experience both in other countries and in Holland that, provided they are properly informed, the consumers are prepared to buy irradiated products. Above all, the co-operation of indepen­ dent experts, such as the government (public health departments) can prove to be an important stimulus to acceptance.

11. IRRADIATION OF ONIONS

The feasibility of onion irradiation in a plant installed for potato irradia­ tion has been studied. POTATOES IN THE NETHERLANDS 195

Since onions, like potatoes, have a dormant period, it is of interest to know which period after harvest would be-suitable for onion irradiation. If this period falls before or after the potato-irradiation period (October to mid December), then the source could be used for a longer time. From research carried out by the Sprenger Institute and the ITAL in 1971/1972 and 1972/1973 the following provisional conclusions can be made: (1) Irradiation of onions with gamma rays immediately after harvest strongly suppresses sprout formation and growth of the roots. (2) A 2-weeks delay in irradiation gives less good results. (3) A very low dose of 2 krad already suppresses sprout formation very well. (4) Irradiated onions partly show a slight internal brown discoloration and to a limited extent a somewhat stronger dis coloration of the sprouts. F rom the results it can be gathered that, as for potatoes, the most favourable time for onion irradiation is immediately after harvest. Since potatoes and onions are harvested almost throughout the same period, a combination of both crops for irradiation with one source is not possible.

THE ECONOMIC FEASIBILITY OF ONION, POTATO AND WHEAT IRRADIATION IN INDIA

P. SUDARSAN Programme Analysis Group, Department o f Atom ic Energy, Government of India, Bombay, India

1. THE CONCEPT OF ECONOMIC DOSE

The dose that is generally quoted as the optimum for radiation preserva­ tion of agricultural commodities is often the minimum dose required for 100% effectiveness. For example, 10 krad may be the dose required for 100% sprout inhibition. But generally the dose response relationship is curvilinear, shown in Fig.l. Experiments carried out at various doses have shown that very high effectiveness (90 to 95%) can be achieved with much smaller doses. As an illustration, a dose as low as 5 krad may inhibit sprouting to the extent of 90%, thus using 5 krad rather than 10 krad would enable the through­ put to be doubled, or alternatively a smaller irradiator with half the source strength to be installed. The savings in investment and operating costs and the improvement in the economic viability could be very significant if such an attempt is made to arrive at the optimum economic dose. This means that storage experiments need to be carried out at various doses and the results must indicate not only the minimum dose for 100% effectiveness but also the optimum economic dose, which may be far less.

2. EVALUATION OF NET MONETARY BENEFITS OF POSTIRRADIATION STORAGE TO IRRADIATOR USERS

It is essential, even in the early stages of a project proposal, to demons­ trate the potential monetary benefits to the likely users (farmers and traders) of an irradiation facility. This is necessary to obtain the support and co­ operation of the intended beneficiaries, the industry, financial institutions and various other organizations whose collaboration is required from the stage of formulation to the stage of execution and during operation. Estimates of monetary benefits are also essential for assessing the potential demand for irradiation, to arrive at the optimal irradiator size, and to determine the economic feasibility of the project as a whole. For evaluating the net monetary benefits of postirradiation, storage and subsequent sale, compared to storage without irradiation, the following simplified methodology is proposed. The data required are: (a) the maximum period of storage needed. This would be the period between the start of fresh arrivals in two successive crops. For example, fresh Rabi onions, which are required for storage in India, start arriving in April while the next Khariff crop starts in October. The intervening period is about 7 months.

197 198 SUDARSAN

F IG .l. Dose effectiveness curve.

200

JULY Г AUGUST SEPTEMBER

FIG. 2. Optimal strategy for storage and sale of freshly harvested onions in May, and incremental benefits of irradiation.

(b) Practical storage periods beyond which the irradiated and unirradiated produce becomes unmarketable. A storage experiment with Rabi onions showed that the respective periods are 4 and 3 months, (c) Period of fresh arrivals. Fresh Rabi arrivals start in April and extend up to mid-June (2-§- months), (d) Total losses during successive intervals of this storage period, with and without irradiation, (e) Market price behaviour during the storage period. Generally the prices steadily rise during the period between ECONOMICS IN INDIA 199

two successive harvests, (f) Total storage costs (rent plus interest on original value). This cost generally varies linearly with the period of storage, (g) Cost of irradiation. The objective now would be to find out for each month of fresh arrivals (April, May or June) the optimum period of storage with and without irradiation and the incremental monetary benefits of irradiation. Taking the example of fresh arrivals in May, they can be stored up to September (4 months) after irradiation and only up to August (3 months) without irradiation. Using the data on market prices, losses for various feasible storage periods, costs of storage and irradiation, the net revenues realizable with and without irradiation as a function of storage period can be plotted, as shown in Fig.2. The optimal months of sale for unirradiated and irradiated produce are July and September, after 2 and 4 months' storage respectively. The incremental benefit of irradiation is Rs. 18 per tonne, or 13% of the initial value (in May) of produce stored. A similar analysis for fresh arrivals in April and June shows that the incremental benefits of irradiation are 14% and 21% of the original value of the produce respectively.

3. POTATO IRRADIATION

The annual production of potatoes in India is 4.5 to 5 million tonnes. Areas of concentrated production and large distribution/consumption centres have been identified where potato irradiation maybe economically feasible. Detailed feasibility studies in individual locations have not been completed. Unlike for onions, radiation preservation of potatoes would have to compete with the fairly well-established alternative, cold storage at 0-4°C. Again unlike irradiated onions, which are proposed to be stored at ambient tempera­ ture (28 to 30°C), potatoes may require postirradiation 'cool' storage (about 15°C). Preliminary estimates show that the cost of irradiation (8 to 10 krad), followed by air-cooled storage at 15°C would be less than that of cold storage (0-4°C). Significant quantities of potatoes are grown in hilly areas where ambient temperatures vary from 10 to 20°C. After harvest these potatoes are brought down to the plains for marketing, storage (including cold storage) and distri­ bution. An idea being investigated is the feasibility of locating potato irradia­ tors in concentrated growing areas in the hills, where the irradiated produce could perhaps be stored under ambient conditions. This may eliminate the need for controlled air postirradiation storage, which may be 2 to 3 times as expensive as irradiation. Radiation preservation of potatoes would effect significant savings in energy consumption and cost. The annual cost of gamma energy for a through­ put of 25 000 tonnes is Rs. 65 000 and the cost of power for cold storage (15°C) is about Rs. 500 000, totalling Rs. 0.565 million. In comparison the cost of power for cold storage is about a million rupees.

4. LOCATION OF IRRADIATORS FOR ONIONS AND POTATOES - PRODUCTION VERSUS CONSUMPTION CENTRES

As onions must be irradiated as soon as possible after harvest, the feasibility of locating onion irradiators in consumption centres would be •limited. However, as potatoes have a higher dormant period, this restriction

\ \ 20 0 SUDARSAN

I may not apply to them. Even in the case of onions, a large consumption centre] Bombay, is located only about 200 km from the growing areas and fresh produce can be transported to Bombay within a day or two. Generally, metro­ politan consumption centres receive much larger quantities of produce than the arrivals in production centres. For example, Bombay receives annually 100 000 tonnes of onions, while Lasalgaon, the largest onion assembling market in the country, has annual arrivals of only about 75 000 tonnes. In addition, consumption centres receive significant quantities of other commo­ dities that are also amenable to irradiation. This would create a multiproduct capability for an irradiator in such centres. For example, Bombay receives annually about 200 000 tonnes of potatoes. Since the harvest periods of onions and potatoes differ to some extent, an irradiator in consumption centres could perhaps be operated for longer periods than an irradiator in a production c e n tre . Another advantage of locating in consumption centres is that, as the produce nears the consuming end, its value increases appreciably and there­ fore the cost of irradiation as a percentage of the value of the commodity would be less in consumption centres. Against this factor we must recognize that the cost of storage in city consumption centres may be higher than in the production areas. However, the main beneficiaries of an irradiator in a consumption centre like Bombay would be the city traders. With a host of middle-men separating the farmer from the consumer, the average farmer may benefit very little from a city-based irradiator.

5. WHEAT DISINFESTATION BY IRRADIATION

India produces about 26 million tonnes of wheat annually. Estimates of post-harvest losses in wheat vary widely, but one authoritative estimate is 11% total losses, of which 3% is credited to insect infestation. Radiation disinfestation of wheat can compete on economic grounds with chemical fumigation only at irradiator throughputs above 30 to 40 t/h for a cobalt facility. Such an irradiator would require large centralized silo complexes (about 200 000 t) for postirradiation storage. At present the largest silo complex in India has a total capacity of about 100 000 t. The alternative to postirradiation storage in hermetically sealed silos would be the development of cheap insect-proof bags. Irradiated wheat could then be stored in bags in conventional godowns. Because of the seasonality of grain arrivals and the need to irradiate rapidly, the irradiator throughput must permit the handling of a substantial part of the peak load. This would result in considerable under­ utilization of the capacity. An alternative would be to limit the hourly throughput so as to spread out irradiator operation over a longer period, and use fumigation as a holding operation to control infestation in the bins where ' the wheat is stored awaiting irradiation. Radiation disinfestation is m ore suitable than fumigation for long-term storage purposes. However, it must be remembered that in many countries there are two crops and the feasibility of bi-annual stock-turnover may obviate the need for storing the grain for more than 6-7 months. Port-based irradiators at wheat-importing countries have been suggested. The main problem here is the wide fluctuations in annual imports and stoppage ECONOMICS IN INDIA 201 of imports in years when local harvests are good. These considerations may reduce the long-term economic viability of such irradiators. In India serious consideration is being given to the setting up of modern storage facilities in producing areas rather than centralized storage com­ plexes near consumption centres, among other reasons, to reduce the build-up of infestation at an early stage and thereby reduce losses considerably. Such decentralization may decrease the prospects of disinfestation by gamma ra d ia tion . In such situations, portable, truck-mounted machine sources, such as resonant transformers, may provide an economic alternative.

CONSUMER ATTITUDES TOWARDS FOOD IRRADIATION IN THE NETHERLANDS

J. G . van KOOÜ Institute for Atom ic Sciences in Agriculture, Wageningen, The Netherlands

A nation-wide survey amongst 670 housewives was carried out by the Netherlands Institute for Public Opinion and Marketing in November 1973. The survey consisted of 11 questions, which can be divided into the following se ctio n s : (a) Familiarity with the process of irradiation and irradiated products (b) Opinion on food irradiation (c) Buying of irradiated food (d) Willingness to co-operate in product testing.

RESULTS

(a) 37% of those replying appeared to be familiar with the process of food irradiation. Within this group 50% described the goals of irradiation c o r r e c t ly . (b) The opinion of 7% of those 37% was positive towards food irradiation; 40% was reluctant; and 10% was indifferent. Over 40% had no opinion. Since a large group of those replying (63%) appeared to be unfamiliar with food irradiation, an explanation of food irradiation was presented during the interview, with the result that 40% reacted positively after being informed; 20% could not express their opinion, and the rest of the housewives reacted indifferent ways (non-classified). (c) 26% showed for some reason interest in buying irradiated food; 37% were not sure; and 36% were not prepared to buy irradiated food. (d) 59%, an encouraging percentage, was willing to co-operate in product-testing trials with irradiated food items. 41% showed no interest in such trials.

203

SUMMARY AND RECOMMENDATIONS

SUMMARY AND RECOMMENDATIONS

In view of the impending world-wide food crisis, responsible national authorities and international organizations are deeply concerned about preventing or reducing national and global food losses. It is well recognized by food scientists in many countries that ionizing energy is capable of pre­ serving the quality of a number of food items in its original state for con­ siderable periods of time by retarding or preventing physiological processes in higher organisms or by destroying or inhibiting the growth of insects and/or microorganisms in food. A number of irradiated foods have received public health approval in various countries. It would appear then that in these countries the approved irradiated foods would become commercially available in the market place. However, to date, com m ercial-scale food irradiation has been put into practice in one state only. The Directors General of FAO and IAEA through their Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture convened a panel of experts to discuss the reasons for the apparent inertia in introduction of the process and to recommend ways and means to overcome it. In March 1974 16 experts from 13 countries gathered in Vienna for the discussion and to advise in this matter. WHO and the Commission of the European Communities were also represented. The discussion was concentrated mainly on: (1) the technological and economic feasibility of irradiation; (2) public health acceptance problems; (3) identifying major obstacles of introduction; and (4) the development of action plans for commercialization of the use of irradiation (i) in sprout inhibition of potatoes and onions, (ii) in growth retardation of mushrooms and (iii) in disinfestation of wheat and wheat products, i.e. in the treatment of commodities for the irradiation of which unlimited public health clearances have already been granted in one or more countries. Beside these items, radiation treatment of a number of other commodities was also considered by some participants.

1. TECHNOLOGICAL AND ECONOMIC FEASIBILITY OF FOOD IRRADIATION

The relatively large amount of money, research, scientific and technical effort that has been spent on food irradiation over the past 30 years has resulted from a recognition of the socio-econom ic potential of the various promising food irradiation processes. Commercialization of food irradiation will take place because more and more countries are recognizing the importance of this technology. Members of the Panel and the working paper on the com­ parative economic evaluation of 6 products in 11 countries showed that the irradiation of products accepted for human consumption has considerable economic potential and could be competitive with existing or conventional m eth od s. The Panel stressed that irradiation is the only industrially feasible process for long-term sprout inhibition of bulbs (onions, garlic, etc.).

207 208 SUMMARY AND RECOMMENDATIONS

The Panel noted that most oí the technological parameters of the use of irradiation for sprout inhibition in potatoes, onions and garlic, for the dis­ infestation of wheat and wheat products and of rice, for increasing the shelf- life of mushrooms and strawberries, and for microbiological decontamination of animal (poultry) feed (up to dose levels indicated in the respective clearances or petitions) have been satisfactorily established. However, determination of the optimum irradiation parameters for some local varieties has still to be carried out. For example, the efficiency of irradiation of bulbs like onion, garlic or shallot depends on the variety and the time of treatment, some varieties of potatoes show some discoloration after culinary processing, and some strawberry varieties may show-textural softening upon irradiation. It was felt that there was need for acceleration in the technological studies of irradiation of a wider variety of food items with a priority on items of special interest to developing countries. In some countries, particularly in certain developing ones, where there are no big storage centres, a prerequisite of introduction of food irradiation is the availability of one or more transportable, simple irradiation facilities, allowing pilot-scale processing at the places where required. Economic feasibility depends on a number of factors of agricultural, technical, organizational, commercial and psychological nature. These factors should be considered from the viewpoint of the socio-econom ic struc­ ture of each country and even in different regions within the same country. For instance, in developed countries the existence of well-established prac­ tices such as chemical treatment for sprout inhibition and for insect dis­ infestation, or refrigeration, together with vested com m ercial interest in these methods and the availability of excellent infrastructure may diminish the incentives for introducing a new technique such as radiation preservation. In the case of developing countries, on the other hand, where the con­ ventional methods are not established and the associated infrastructure is imperfectly developed, the irradiation alternative offers an opportunity to reach the desired effects faster and more economically than by conventional technology. Moreover, in countries where adverse climatic conditions induce greater losses and reduce the efficiency of traditional practices the economic viability of irradiation is strengthened. Despite the greater need and potential in such countries, detailed feasi­ bility studies have not yet been carried out sufficiently on individual products and specific locations so as to exploit this potential. As irradiation is a large-scale process and can compete with conventional techniques only where large throughputs and longer periods of operation are feasible, it may be economically applicable only where there is concentrated production or sto ra g e . Apart from physical infrastructure, the centralization of operations required by irradiation necessitates adequate organizational infrastructure, for example, by creating or strengthening farm ers' co-operatives, trading networks, etc. It was felt that there is a need for further detailed economic studies to establish the potential and com m ercial feasibility of irradiation for each product and promising location, at both the national and the international levels. In view of the limited number of such studies carried out so far in developing countries, this is of particular importance to them. The economic feasibility studies must incorporate comparison with alternative existing technologies or methods. SUMMARY AND RECOMMENDATIONS 209

Economic feasibility requires analysis from the point of view of the immediate investor. In some cases also the national economic benefits may be considerable, while the purely com m ercial viability of the project may be less. In such instances it may be necessary to subsidize the investment from appropriate national sources. In view of the fact that countries that have clearances for irradiated potatoes, onions, etc. are exporting potatoes, chemically treated, to countries in tropical regions, it was considered advisable to inform the importing countries of the advantages and benefits of irradiation over conventional treatments. This is an important and practical approach to the introduction of food irradiation in these countries. Acceptance of food irradiation by importing Countries would facilitate the establishment of com m ercial facilities in the exporting countries for irradiation of potatoes, onions, etc. The Panel found that economic feasibility studies should incorporate national/social cost-benefit analysis. To facilitate intercountry comparison on a national basis, it was suggested that the discounted cash-flow methodology should also be included in such cost-benefit analysis and comparisons with conventional methods. Apart from monetary benefits and costs, the social, socio-econom ic and public health benefits of food irradiation processes should be clearly stressed and quantified if possible. In view of the likely improvement in feasibility of food irradiation projects if international trade in irradiation foods is permitted, as well as from other considerations, international collaboration is essential on a continuing basis. In addition, groups of countries having sim ilarities in needs, problems, conditions and practices, such as developing countries, would benefit from greater collaboration among themselves. It was pointed out that, in the context of the current energy crisis, savings in energy consumption by irradiation processes compared to energy- intensive conventional techniques such as refrigeration must be given due consideration.

2. PUBLIC HEALTH ACCEPTANCE OF FOOD IRRADIATION

The representative of WHO reminded the Panel of the fact that the FAO/IAEA/WHO Expert Committee, in 1969, recommended 'temporary acceptance' only, for potatoes, wheat and wheat products. In the view of the WHO, care should be exerted in this field until the decision of the next Expert Committee, at present scheduled to meet in 1975, becomes known. The Panel noted, however, that, during the last 3 years, there has been a considerable increase in the number of irradiated food items approved for consumption and in the number of countries clearing such commodities. Figure 1 gives the date of first clearance in each country, whereas Table I shows a list of expected clearances in the 1 or 2 years after the Panel. This rise is due both to an ever-increasing amount of experimental data that gives no reason to doubt the safety of irradiated food, and to an increasing concern about the use of chemicals in food and in the environment. Improvement of the hygiene of food requires a treatment that decreases or avoids chemical residues, a requirement that can be met by irradiation. Besides, the use of irradiation constitutes the method of choice in decreasing the incidence of Salmonella and other pathogens. The Panel considered this development to be very positive because it improves food quality. 210 SUMMARY AND RECOMMENDATIONS

UNDERLINING INOICATES UNIIMITEO CLEARANCE IN A7 LEAST ONE STATE

1 9 - GARLIC 18 - SPICES AND CONDIMENTS 17 • SHRIMPS

16 • DIETS FOR HOSPITAL PATIENTS COUNTRY COPE : 15 BUL BULGARIA DEEP FROZEN MEALS FOR PATIENTS К CAN CANADA DEN OENMARK COCOA B E A N S 13 FRA FRANCE FRG FED.REP.GERMANY STRAWBERRIES 12 сл HUN HUNGARY ASPARAGUS 2 ISR ISRAEL ш 11 ITA ITALY MUSHROOMS о 10 JPN JAPAN о NET NETHERLANDS о CULINARY MEAT PROOUCTS PHILIPPINES ^ 9 SPA SPAIN DRY FOOD CONCENTRATES THA THAILAND UNITED KINGDOM POULTRY USA UNITED STATES OF AM E R IC A DRIED FRUITS USSR SOVIET UNION

URU URUGUAY ONIONS

UNDERLINING FRESH FRUITS AND VEGETABLES

BEEF, PORK, RABBIT { SE Ml - P R E P A R E D )

WHEAT AND WHEAT FLOUR

G R A IN

POT A T O E S

19 58 59 6 0 61 6 2 63 6 4 6 5 6 6 67 6 8 5 9 7 0 71 7 2 73

FIG. 1. Irradiated foods cleared in one or more countries as of December 1973, with dates of first clearance.

The Panel expressed much interest in new wholesomeness approaches that aim at an authorization of the irradiation process in contrast to licensing irradiated foods item by item. It considered this as an essential aspect to be taken into account in formulating the future programme of the Internationa] Project in the Field of Food Irradiation (IFIP, Karlsruhe). Seeking equal treatment for exporting and importing countries in matters of authorization, the Panel urged the evaluation of available wholesomeness data at an international level.

3. OBSTACLES TO THE COMMERCIALIZATION OF FOOD IRRADIATION

It is generally recognized that the industrial introduction of most new food-processing techniques has always been a time-consuming procedure. SUMMARY AND RECOMMENDATIONS 211

TABLE I. NEW CLEARANCES EXPECTED TO BE PETITIONED AND/OR ISSUED IN THE FORESEEABLE FUTURE

Nature of petition C o u n try P rod u ct P e titio n C le a r a n c e or clearance expected

B e lg iu m Various food items 1 9 7 4 Laboratory quantities

B ra zil

Czechoslovakia P o ta to es 1 9 7 4 O nions 1 9 7 4

M u sh room s 1 9 7 5

W h e a t 1 9 7 4

F rance Corn starch

S p ic e s 1 9 7 5

F eed stu ffs 1 9 7 4

S h a llo ts 1 9 7 4

O n ion s 1 9 7 4 G a r lic 1 9 7 4

FRG P otatoes 1 9 7 4 1 9 7 4 Limited quantities

Fish ( 1 9 7 2 ) 1 9 7 4 Limited quantities O n ion s 1 9 7 4 1 9 7 5 Limited quantities

H u n gary Pap rik a 1 9 7 4 1 9 7 4 Experimental batches

Mixed spices 1 9 7 4 1 9 7 4 Experimental batches .

India P o ta to es W h e a t - ( 1 9 7 0 ) O n ion s

Fish and shrimps

Israel Wheat and wheat

prod ucts ( 1 9 7 0 ) 1 9 7 4 ( ? )

G a r lic 1 9 7 4 1 9 7 5 ( ? )

Spices (mixed) 1 9 7 4 1 9 7 5 (? ) M u sh room s 1 9 7 4 or 75 1 9 7 5 (? )

Strawberries 1 9 7 4 or 75 1 9 7 6 (? ) M a n g o e s 1 9 7 5 (? ) 1 9 7 6 (? )

/ A v o c a d o 1 9 7 6 ( ? ) 1 9 7 7 (? )

Ita ly Wheat and wheat

prod ucts soon U n lim ite d

Strawberries soon U n lim ite d

M u sh room s soon U n lim ite d Animal feed soon Experimental batches 212 SUMMARY AND RECOMMENDATIONS

TABLE I. (cont.)

Japan Rice W h e a t К а т а Ъ о ко S au sages

O nions 1 9 7 5

The Netherlands Chicken 1 9 7 4 U n lim ite d Onions 1 9 7 4 ( ! )

S p ic e s 1 9 7 4 U n lim ite d

S p a in O nions ( 1 9 7 0 ) 1 9 7 4

USA P a p a y a 1 9 7 4 1 9 7 5 U n lim ite d Strawberries 1 9 7 4 1 9 7 5 U n lim ite d

M e a t 1 9 7 7 U n lim ite d

For example, application of food canning on a truly industrial scale took about a hundred years after its invention, quick-freezing of foods was also delayed by a few decades, although, at that time, none of these procedures had to undergo lengthy examinations for wholesomeness, in fact, not even long after | their large-scale application. Viewed against this background, lack of prac­ tical introduction of food irradiation 'only' about twenty years after its technological conception is not surprising. However, in view of the general acceleration of technical progress, on the one hand, and that of food shortage, on the other, a much quicker pace could have been anticipated for the intro­ duction of this technique in the second half of the twentieth century. Several factors are at work decreasing the desired speed of introduction of food irradiation and the Panel was requested to identify them and evaluate their effects in a comparative way. At the end of the general discussion, therefore, all participants were specifically asked to point out the main reasons for the lagging practical introduction of this new food processing method. Of the 13 countries represented at the Panel, two have no serious problems in this field. In fact, introduction of industrial food irradiation has already started in Japan in January 1974 (for details and size of the operation see the paper by Umeda). In two of the remaining 11 countries the lack of national clearances constitutes one of the main obstacles. The Panel recommended that competent local authorities urge all national public health agencies to consider regulating! food irradiation and to consider specific clearances as a matter of urgency. I Scientists from 5 of the 9 countries having positive regulations on some of the irradiated foods in question considered the present lack of international, general clearances as the most important stumbling block. Four of the scientists specifically referred to the difficulties caused by the limited number of importing countries having public health approval for irradiated foods. One participant specifically pointed out the potential danger that might be caused to the national economy by approving the irradiation of an important export item. In his view, such an approval might undermine confidence in the SUMMARY AND RECOMMENDATIONS 213

exporter, in the country and in the product and, thus', might have adverse effects also on the sale of the non-irradiated commodity to an importing country that does not allow irradiation of the same food. Collaboration with international organs like the Codex Alimentarius Commission was urged. Participants from 6 of the 13 countries represented at the Panel thought that irradiation of potatoes and grain, although economically competitive, can become commercially interesting only if the use of chemicals is forbidden or subjected to the same health and labelling standards as those for irradiated food. They pointed out that although products that are treated with chemicals (the amounts of which have to be limited because of their untoward effects on the human organism) are universally acceptable without discriminatory labelling, when irradiated the same products have to meet exacting health and labelling standards. To give an example: in almost all countries where irradiation of potatoes has been permitted such potatoes must be labelled "irradiated", while in the same countries potatoes treated with chemical sprout inhibitors do not require a corresponding label. This unjustifiably favours the use of chemicals, causes complacency in the trade and diminishes com m ercial interest in food irradiation. The lack of knowledge, in the food industry and the public, about the irradiation process was also mentioned by several participants as a major obstacle to the expansion of trade in irradiated food. It was suggested that national authorities should undertake to inform the industry and the public at la rg e .

4. ACTION PLANS TO INTRODUCE FOOD IRRADIATION

On the basis of the deliberations, a few guidelines for those interested in, and involved with, the introduction of food irradiation have been formulated. (1) Carry out experiments on a sufficiently large scale to demonstrate cogently the technological feasibility of radiation treatment of food items of special economic importance. (2) Establish collaboration not only with atomic energy authorities but also with the m inistries dealing with agriculture and food and/or with industry and especially with research institutes belonging to the above fields. Intimately involve food technologists, entomologists and post-harvest physiologists with the experiments on technological feasibility of food irradiation. (3) Assess economic feasibility of the process by thorough surveys and analyses of crop availability, costs, etc. in collaboration with agricultural and food economists with special reference to those not affiliated to the atomic energy authority of the country, and if possible at a regional level. (4) Establish close contact and collaboration with public health authorities at an early stage. Should additional wholesomeness studies be required, ask the health authorities to give advice on designing the experiments on the irradiated product(s) concerned and keep them informed on the progress of these experiments. Convince the delegate of the country to the World Health Assembly to emphasize the importance, especially to developing countries of the hygienic, nutritional and economic advantages of adopting the new process. (5) Have the m inistries of industry and com m erce (internal and/or external trade) get involved in all attempts at comm ercialization of irradiated foods, e.g. demonstrate to food manufacturers and the food trade the technological and economic advantages of the process by supplying them with reliable detailed information. 214 SUMMARY AND RECOMMENDATIONS

(6) Collaborate with the press and other media of mass communication (radio, TV, etc.) to spread balanced, objective information to the general public, to the prospective consumers, and consumer organizations. Special I importance should be assigned to contacts with, and information for, members of the legislative bodies of the country (representatives, senators, etc.). (7) Collaborate with international organizations (a) To facilitate the assessment of available wholesomeness data, thereby increasing the number of national clearances for irradiated food items and, eventually, to reach international clearance of the process of food irradiation; (b) To facilitate carrying out large-scale technological experiments, by the establishment of an international facility for food irradiation technology and economics; (c) To reach international agreement on standardizing the irradiation process; (d) To develop principles for the facilitation of international trade in irradi­ ated foods, e.g. labelling. (8) Where likely to be helpful, prepare the way of food irradiation by introducing sterilization (radappertization) of food packaging materials and/or other auxiliary materials or minor ingredients (e.g. spices, enzyme prepara­ tions, etc.) as well as animal feedstuff s. In connection with guidelines extensive discussion took place of a recent Dutch proposal to facilitate large-scale evaluation of technological and economic feasibility of food irradiation on an international level. (1) The Panel was informed by D. de Zeeuw of an offer of the Dutch Government made at the 17th General Conference of the Agency of making available — through the Agency, for the use of other Member States — the facilities of its pilot-plant at Wageningen to carry out feasibility studies on a commercial scale. (2) The Panel expressed its belief that such a project would provide an excellent opportunity to conduct, through international co-operation, high- standard, independent studies and development work, together with training in the fields of technology, economics and marketing of irradiated food. At the same time it could serve as an international centre for collecting and disseminating information on developments in the above fields. The interest in assisting this project, shown by the representative of the Commission of the European Communities, was noted with satisfaction. ■ (3) The Panel, in general, welcomed the Dutch offer. Those participants who were interested in the establishment of such an international project suggested that the envisaged project should comprise: (a) Examination of factors affecting the technological feasibility of individual products that are of special interest to developing countries; (b) Study of factors affecting the economic feasibility of individual products with special emphasis on regional conditions; (c) Evaluation of factors affecting the commercialization aspects of individual products with special reference to international marketing; (d) Facilitation of the free flow of information on the above subjects; and (e) The exchange of experts and trainees between Member States in the project.

i RECOMMENDATIONS

(1) Since isolated national public health approval (clearance) of an irradi­ ated food item, although encouraging, in itself is of limited value, regional SUMMARY AND RECOMMENDATIONS 215

and, preferably, world-wide clearance should be attained in the foreseeable future. In this respect, existing international organizations either with re g io n a l1 or world-wide 2 responsibilities are asked to contribute by means of harmonizing legislation and administrative procedures and by convening as soon as possible an FAO/lAEA/WHO Expert Committee to evaluate the results of recent research on the wholesomeness of irradiated food to which major contributions are expected to come forth from the International Project in the Field of Food Irradiation. (2) The competent international organizations are urged to facilitate the exchange of practical experience of Member States in the evaluation of wholesomeness data and in the procedures leading to the issuance of public health approvals. (3) Noting the increasing world-wide concern about the use of chemicals for the preservation of food and about the impending food shortage, the Panel recommends that in the public health evaluation of the food irradiation process the above concern should be taken into consideration. It should be stressed that it is hardly in the interest of public health to require irradiated foods to be labelled "irradiated" when, at the same time, chemically treated foods are not labelled correspondingly. (4) It is recommended that the possibilities of granting public health approval to groups of related products be seriously considered. In addition, the Panel recommends a general world-wide clearance of low-dose (up to 50 krad) treatment of all foodstuffs to be considered in the near future, with the consideration of a higher-dose treatment following at some later date. (5) Competent international organizations are requested to collect and disseminate information to national administrative authorities and consumer organizations about the technological, economic and public health benefits of food irradiation to assist them in legislation on food irradiation. (6) Since radiation preservation of a number of food items has been proved technologically feasible and has been demonstrated to improve quality as well as to significantly increase available quantities of these important staple foods, and have already been given clearance in several countries, the Panel recommends that those engaged in the introduction of food irradiation in Member States of the IAEA and FAO, petition their respective health authorities to clear all these products on the basis of available wholesomeness data and clearances, notwithstanding possible local com m ercial irrelevance of these products when considering the petitions. This is a major pre­ requisite (i) of international trade in irradiated food products and, hence (ii) of encouraging commercial organizations to proceed with commercialization. (7) It is recommended that the Joint FAO/lAEA Division of Atomic Energy in Food and Agriculture obtain and disseminate relevant information on results of economic and com m ercial operations accumulated in pilot plants, in currently proposed com m ercial food irradiation facilities and, in particular, in the first com m ercial potato irradiator in Japan and encourage the Japanese authorities to co-operate with the IAEA in carrying out this task.

1 Such as the Asian Industrial Development Council (АШ С), the Council of Mutual Economic

Assistance (CM EA), the European Communities (EC), the Latin American Free Trade Association (LAFTA), the League of Arab States (LAS), the Organization of African Unity (OAU), the Organization of American

States (OAS), etc.

2 Such as IAEA. FAO and WHO. 216 SUMMARY AND RECOMMENDATIONS

(8) The Panel recommends to the IAEA and FAO to consider seriously J the offer of the Dutch Government to establish an international facility for food irradiation technology, and feels that formal consultation with interested Member States on the establishment and on its programme should be encouraged with special emphasis on the studies concerning food items of special interest to developing countries. (9) It is recommended that the IAEA and other interested agencies support a small working group in an attempt to locate, by whatever means appropriate, no longer used irradiators and to design necessary auxiliary equipment to convert these into transportable units and to prepare low -cost transportation schedules for existing mobile irradiators. (10) The Panel recommended that FAO and IAEA facilitate co-ordinated international work on larger-scale commercialization trials to be conducted in various Member States. The possibility of establishing an international taskforce of experts with experience in commercialization should be examined with a view of using this mobile team to secure the performance of well- designed, objective and valid trials in various'Member States. i (11) It is recommended that public information activities at the national and international level be initiated. LIST OF PARTICIPANTS

PANEL MEMBERS

F. de la Cruz Division Química Nuclear, Junta de Energía Nuclear, Av. Complutense, M a d r id -3 , Spain

J. D eitch US Department of Commerce, Domestic and International Business Administration, Washington, D.C., United States of America

J.F. Diehl (Chairman) Bundesforschungsanstalt für Lebensmittel­ frischhaltung, Engesserstrasse 20, 75, Karlsruhe, Federal Republic of Germany

J. F a rk a s Central Food Research Institute, Hermann Ottó út 15, H-1022 Budapest, H ungary

M. Lapidot Soreq Nuclear Research Centre, Y avn e, I s r a e l

W. Schietecatte Application of Ionizing Radiations, Institut National des Radioéléments, с/o SCK/CEN, Mol, B elgiu m

P. Sudarsan Programme Analysis Group, Department of Atomic Energy, Government of India, C.S.M. Marg, B o m b a y -3 9 , India

K . U m eda National Food Research Institute, K o to -k u , T ok y o, Japan

217 218 LIST OF PARTICIPANTS

D. de Zeeuw Institute for Atomic Sciences in Agriculture, Postbus 48, Wageningen, The Netherlands

L. Zonenschain APIA, Grupo Economico, Programa de Irradiaçâo de Alimentos, Comissào Nacional de Energia Nuclear, Rio de Janeiro, Guanabara, Brazil

O B SE R V E R S

D . B a ra ld i Laboratorio per le Applicazioni in Agricoltura, CSN, Casaccia, R o m e , Italy

P . H ora cek Czechoslovak Atomic Energy Commission, S lezsk á 9, 12009 Prague 2, Czechoslovakia

J.G. van Kooij Institute for Atomic Sciences in Agriculture, Postbus 48, Wageningen, The Netherlands

F . Sandret Ecole Nationale Supérieure des Industries Agricoles et Alimentaires, CERDIA, 92305 Massy, F ra n ce

H. Sparenberg Institute for Storage and Processing of Agricultural Produce, Postbus 18, Wageningen, The Netherlands

P . V id a l CONSERVATO ME, 22, Boulevard Georges Clemenceau, 92400 Courbevoie, F ra n ce

REPRESENTATIVES OF INTERNATIONAL AND INTERGOVERNMENTAL ORGANIZATIONS

E.A. Asselbergs Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, R om e LIST OF PARTICIPANTS 219

M. Cam cigil Legal Division, International Atomic Energy Agency, V ienna

T. Fawi Abdu Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture, V ienna

H. Glubrecht Department of Research and Isotopes, International Atomic Energy Agency, V ienna

G. P r ô p s tl Bureau EURISOTOP, Commission des Communautés Européennes, 200 Rue de la Loi, B r u s s e ls

M . S en tici World Health Organization, Liaison Office IAEA, Vienna

SCIENTIFIC SECRETARY

K. Vas Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture, V ienna

EDITOR

C.N. Welsh Division of Publications, International Atomic Energy Agency, V ienna I

HOW TO ORDER IAEA PUBLICATIONS

Exclusive sales agents for IAEA publications, to whom all orders and inquiries should be addressed, have been appointed in the following countries:

UNITED KINGDOM Her Majesty's Stationery Office, P.O. Box 569, London SE 1 9NH UNITED STATES OF AMERICA UNtPUB, Inc., P.O. Box 433, Murray Hill Station, New York, N.Y. 10016

In the following countries IAEA publications may be purchased from the sales agents or booksellers listed or through your major local booksellers. Payment can be made in local currency or with UNESCO coupons.

ARGENTINA Comisión Nacional de Energía Atómica, Avenida del Libertador 8250, Buenos Aires AUSTRALIA Hunter Publications, 58 A Gipps Street, Collingwood, Victoria 3066 BELGIUM Service du Courrier de l'UNESCO, 112, Rue du Trône, B-1050 Brussels CANADA Inform ation Canada, 171 Slater Street, Ottawa, Ont. K 1 A O S 9 C.S.S.R. S.N.T.L., Spálená 51, CS-11000 Prague Alfa, Publishers, Hurbanovo nâmestie 6, CS-80000 Bratislava FRANCE Office International de Documentation et Librairie, 48, rue Gay-Lussac, F-75005 Paris HUNGARY Kultura, Hungarian Trading Company for Books and Newspapers, P.O. Box 149, H-1011 Budapest 62 INDIA Oxford Book and Stationery С отр., 17, Park Street, Calcutta 16 ISRAEL Heiliger and Co., 3, Nathan Strauss Str., Jerusalem ITALY Librería Scientifica, Dott. de Biasio Lucio "aeiou", Via Meravigli 16, 1-20123 Milan JAPAN Maruzen Company, Ltd., P.O.Box 5050, 100-31 Tokyo International NETHERLANDS Marinus N ijhoff N.V., Lange Voorhout 9-11, P.O. Box 269, The Hague PAKISTAN Mirza Book Agency, 65, The Mall, P.O.Box 729, Lahore-3 POLAND Ars Polona, Céntrala Handlu Zagranicznego, Krakowskie Przedmiescie 7, Warsaw ROMANIA Cartimex, 3-5 13 Decembrie Street, P.O.Box 134-135, Bucarest SOUTH AFRICA Van Schaik's Bookstore, P.O.Box 724, Pretoria Universitas Books (Pty) Ltd., P.O.Box 1557, Pretoria SPAIN Nautrónica, S.A., Pérez Ayuso 16, Madrid-2 SWEDEN C.E. Fritzes Kungl. Hovbokhandel, Fredsgatan 2, S-10307 Stockholm U.S.S.R. Mezhdunarodnaya Kniga, Smolenskaya-Sennaya 32-34, Moscow G-200 YUGOSLAVIA Jugoslovenska Knjiga, Terazije 27, YU -11000 Belgrade

Orders from countries where sales agents have not yet been appointed and requests for information should be addressed directly to: Publishing Section, International Atomic Energy Agency, Kàrntner Ring 11, P.O.Box 590, A-1011 Vienna, Austria

INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1975 PRICE: US $14 .0 0 SUBJECT GROUP: I Austrian Schillings 230,— Life Sciences/Food Preservation (£5.80; F.Fr. 60; DM 32,-)