VG321 The continuous cooking of onions for food processing and food service application Penny Hlavaty Food Design Pty Ltd VG321 This report is published by the Horticultural Research and Development Corporation to pass on information concerning horticultural research and development undertaken for the onion industry. The research contained in this report was funded by the Horticultural Research and Development Corporation with the financial support of the Masterfoods Australia Limited. All expressions of opinion are not to be regarded as expressing the opinion of the Horticultural Research and Development Corporation or any authority of the Australian Government. The Corporation and the Australian Government accept no responsibility for any of the opinions or the accuracy of the information contained in this Report and readers should rely upon their own inquiries in making decisions concerning their own interests. Cover Price $20.00 HRDC ISBN 1 86423 499 7 Published and Distributed by: Horticultural Research and Development Corporation Level 6 7 Merriwa Street Gordon NSW 2072 Telephone: (02) 9418 2200 Fax: (02) 9418 1352 © Copyright 1997 FINAL REPORT THE CONTINUOUS COOKING OF ONIONS FOR FOOD PROCESSING AND FOOD SERVICE APPLICATION PROJECT NO.VG321 HORTICULTURAL RESEARCH AND DEVELOPMENT CORPORATION MASTER FOODS OF AUSTRALIA PENNY HLAVATY Project Chief Investigator KAREN MURDEN Food Technology Gradeuate Assistant FOOD INDUSTRY DEVELOPMENT CENTRE Project Manager Table of Contents Executive Summary 1 1. Introduction 3 1.1 Literature Survey on Onions and Capsicum 4 2. Methodology 5 3. Onion Project Market Research Report 6 3.1 Methodology 3.2 Food Manufacture 3.3 Results for Manufacturers 8 3.4 The Food Service Industry 3.5 Response in the Food Service Sectors 9 3.6 Conclusion 11 4. Catergrill Technical Report 12 4.1 The Catergrill 4.2 Adjustments 4.3 The Cooking and Browning of Onions 13 4.4 Time/Temperature Trials with the Catergrill 4.5 Modifications to the Catergrill 4.6 Trials at Master Foods of Australia 14 4.7 Power for Heating the Catergrill 15 4.8 Heat Measurement 4.9 The Process for the Continuous Cooking of Onions 17 4.10 Recommendations for Improvements to the Catergrill 4.11 Cutting Equipment 18 Conclusion and Recommendations 19 Acknowledgments 20 Appendix 21 Onion Market Survey Questionnaire Bibliography Photographs THE CONTINUOUS COOKING OF ONION FOR FOOD PROCESSING AND FOOD SERVICE APPLICATION Executive Summary The project, The Continuous cooking of Onions for Food Processing and Food Service Applications was carried out by Food Design Pty Ltd with the assistance of a grant from the Horticultural Research and Development Corporation, supported by Master Foods of Australia. The Food Industry Development Corporation acted as project supervisor. The aim of the project was to assess the potential for the continuous industrial cooking of onions using a new technology developed by Penny Hlavaty of Food Design. The technology consists of a patented continuous grill, known as the CatergriU, and the cooking techniques developed in conjunction with it. Practical work on the project commenced in October 1993, using the first prototype of the CatergriU. Market Reaserch was carried out in November 1993 and February 1994. Trials in Year 1 of the project were completed in July 1994. Year 2 of the project was intended to complete follow-up work on product yield, scaling up to recommended package sizes and economic feasibility studies. This study is not proceeding, as Master Foods prefer to complete this work themselves. This is the Final Report on this project, and details the achievements of the project in its first year. The project was successful in achieving its aim of demonstrating that a new process for the continuous cooking of onions, using CatergriU technology, is feasible and practical. A variety of onion products were made and assessed for organoleptic quality, shelf life and product safety. Both chilled and IQF products were made and tested. Capsicum products were also tested in similar fashion, but, while easy to process through the CatergriU, were not acceptable, mainly for quality reasons, so work on these products was suspended in April 1994. This report covers the three aspects of the continuous processing of onions which were examined as part of the project. It is in the form of three separate reports, the first on the Results of the Market Research, the second a Technical Report on the CatergriU, the third a Scientific Report covering food technology issues. The Market Research survey indicated that there is potential demand for fully-processed onion products, both among manufacturers of further-processed foods and in high volume catering and hospitality industry outlets. It determines consumer preferences, which are primarily for chilled medium diced translucent onion and lightly browned sliced onion, although quite a large selection of products can be sold. 1 The Technical Report sets out a recommended process for chilled pre-cooked onion products and a similar process for Individually Quick Frozen pre-cooked onion products. The Catergrill works very well, and can produce a product range including the diced and sliced products, as well as innovative products such as very lightly cooked stir-fry style onions and curry base consisting of very finely diced or sliced onion with oil, herbs, spices and flavourings mixed in. All products have a natural appearance, and can hardly be distinguished from traditionally-cooked products. The technical improvements recommended for the Catergrill, to enhance its performance for food manufacture, can be carried out by Food Design's new venture partners, Stainless Associates, who are now working on prototype development. The conclusions of the Scientific Report are equally positive. Trials on onion products were comprehensive and some procedures were innovative. From these trials it was concluded that IQF pre-cooked onion products were preferable to their chilled equivalents, particularly as there was no visual change to the frozen products, unlike their chilled equivalents, which became more uniform in colour during the effective chilled shelf life of three weeks. However, a technique for chilled acidified onion products was developed, so customers preferring chilled products can be assured of the product's safety as well as convenience. The flavour of the acidified products was still mild and suitable for proposed end uses such as on hamburgers and in sauces and wet dishes. The main recommendation of this report are that the project proceed towards commercialisation, as there are so far no barriers to success. This report is to remain confidential on the request of Master Foods of Australia, for two years. 2 ONION PROJECT FINAL REPORT 1. INTRODUCTION In Australia, only five percent of the onion crop is processed into value added product. Most of the processed onion is only peeled, diced or sliced, for sale chilled or frozen to manufacturers and food service operators. This is in dramatic contrast to other basic vegetable crops such as tomato and potato which are further processed in many ways and sold in chilled, frozen, aseptic, bottled, canned and dehydrated forms. It is also in contrast to the USA, where 40% of the crop is dehydrated, 10% peeled or prepared, and some further processed as frozen deep fried onion rings. Yet, even in countries with a large value-added onion industry, there has previously been no industrially efficient method of continuously cooking a range of onion products in a way that gives similar results in appearance and taste to onion freshly sauteed, stir-fried or barbecued on a griddle. Even light cooking markedly alters the appearance and flavour profile of the onion. But many food processing factories lack facilities and machinery suitable for frying onion. Where they do attempt it, the steam-jacketed kettles and brat pans commonly used do not give the same results as hand-cooked onion. Many processors use raw onion, supplemented by fried onion or shallot flavours and other flavour compounds in order to replicate the savory quality of cooked onion. In Food Service operations, larger operators such as food franchises, and large-scale catering and hospitality outlets, purchase quantities of peeled onions and smaller amounts of diced and sliced raw onion. This saves the time taken by staff hand peeling onions. Smaller operators mostly purchase fresh onion, and perceive chilled product as next best to fresh. Yet all sizes of Food Service operations readily purchase frozen potato products, and over half the Australian crop is sold in value added forms. The project titled The Continuous Cooking of Onions for Food Processing and Food Service Applications was proposed as a way of pre-cooking onions to achieve both a natural appearance and flavour and a quick and efficient manufacturing process. It utilises a new Australian technology, which comprises the continuous grilling machine known as the Catergrill and the understanding of cooking processes developed by Penny Hlavaty. These are further explained in the Technical Report. The impact on the onion industry of successful development and marketing of a range of pre-cooked packaged onion products will be radical in the long term. In the same way as the penetration of frozen potato products has been gradual but effective, quality prepared onion products can achieve a large market share, and become the norm in most convenience food operations. Transforming the product gives the chance to transform the economics of the industry by lifting the value of onions from a current contract price of around 12 to 13 cents per kilo, to a fully prepared sale price of around $2 or more per kilo, which exceed the rise in value of frozen potato products. 3 1.1 LITERATURE SURVEY ON ONIONS AND CAPSICUM The project commenced with a literature search on both onion and capsicum, as it was intended to run some trials on a variety of capsicum products also.