G. Guevara, P. F. Abella and E. A. Marfori Bureatr cf Fisherits and Aquui5~Rcs0sozlrce.r hinnih, Philipphes

Abstract

Carp are widespread in ?'he l'hilippines but ;rre not :q>preciatcd by housewivcs because oi their indifferet~t keeping qualities. Experiments have been carried out on smoked and fiHeted products. Organoleptic tests indicate possible consumer preferences and the fish may be stored frozsn or used as a raw matcrial for the preparation of convenience foods.

CONTENTS

I. INTRODUCTION 2. TIXPERIMENTAL PROCEDURES 2.1 Materials 2.2 hfethods 1. RESULTS AND DISCUSSION 3.1 Smokcd product 3.2 Packaged and frozen sticks 3.3 Breaded carp prepared from frozen sticks 4. CONCLUSION I. INTRODUCTION

Common carp, Cypri1zus carpi0 Linnaeus, was introduced into The as early as 1915. Years later, they were stocked in de Ray and Camarines Sur. Carp are at present found in Lake Lanzo, Lake Buhi, , Ambuklao, Caliraya and Angat .

With the fish production programme of the Bureau of Fisheries and Aquatic Resources, the objective of which is to accelerate the pace of fish production, it is expected that carp will be produced in abundance. This will help to alleviate the present deficiency in animal protein as it will serve as a low cost fish product and a good protein source.

Carp in the market usually have a satisfactory flavour and a firm texture. During the hot summer months however, some carp have a musty flavour and soft texture. Their food value remains the same, although palatability may be somewhat decreased. For this reason it has not become popular among housewives. Palatability, however, may be improved by special treatments like soaking in brine mixed with other, spices or pickling in vinegar before drying. These methods of preservation not only improve the flavour but also eliminate losses caused by spoilage of this highly perishable commodity.

These studies are designed to introduce diffxent methods of processing carp and consists of two sections: (a) studies on the keeping quality of smoked carp and (b) freezing and packaging of carp and the preparation of convenience food items.

2. EXPERIMENTAL PROCEDURES

2.1 Materials Common carp are sometimes sold to the cmsumers alive to command better prices.

AH samples used in these experiments were of an average length of 32.87 cm with an average weight of 507 g and procured from commercial markets.

2.2 Methods SMOKING: The belly of the fish is slit to remove the internal organs and the blood along the backbone; the gills are also removed. The fish is then washed thoroughly with water and soaked in concentrated brine solution for 24 hours. The fish are then laid on wire trays to drain the excess brine. The samples are divided into two batches; one is precooked in brine solution and the other smoked without precooking. After arrange- ing on smoking trays they are smoked for two hours. Figure I shows the flowsheet for smoking carp.

PACKAGINGAND FREEZING OF STICKS : The fish are scaled, internal organs are removed and filleted. The rib bones and fins are trimmed away after the fillets have been separated from the skeleton.

After filIeting, they are cut into fish sticks and samples are divided into three batches and packed into three different types of packaging materials such as aluminium foil, wax paper (Cutrite brand) and polyethylene bags before frozen storage. Organoleptic tests are carried out periodically based on the eye appeal, palatability and texture.

PREPARATIONOF BREADED CARP FROM FROZEN STICKS : Fish sticks are portions cut from frozen fish fillets. Fish fillets consist of flesh. cut away from the backbone of the skinned and gutted fish. In The Philip- pines they are now being introduced to housewives as a convenient fish product and are gaining in public acceptance.

Fillets possess advantages over other fish products in that:

(A) they are the most convenient intermediate product for the consumer. It saves them all thc trouble of cleaning and skinning involved in preparing whole fish. (b) They are produced in the right shape and sjz: for packing into standzrd-skd boxes and cmtainers so that the space available for storage can be used to best advantage. (c) Fillets can be made a standard weight which makes them casy to handle in shops. The only disadvantage with fish fillets is the difficulty in preserving the natural extractives and aromatic. substance in the fish flesh.

Figure 2 shows the flowsheet in tIic preparation of breaded sticks from carp.

The preparation of breaded sticks from carp involves the falbwing procedures :

(a) Preparation of fish fillets. (b) Freezing of fish fillets. (c) Cutting of fillets into sticks. The actual sizz of sticks is 3% in length; + in depth and 718 in width. (d) C~atingof raw fish sticks. Batter used in this particular experiment consists of flour, sdt, spices, monosodium glutamatc and baking powder. Bread crumbs are used for bread in^ material. 'I%e bxttcr is made by mixing 2 parts of dry battct to 3 parts water. The resultant smooth susp:ndon coats the raw fish sticks smoothly.

(e) Precooking of coated raw fish sticks by deep-fat fry. After coating the fish sticks, they are manually rolled into bread crumbs, then precooked by means of deep-fat fry. The precooked carp sticks are then cooled and packed in polyethylene bags. (f) In this experiment, samples are divided into five groups; one group is frozzn breaded r.lw and breaded raw stored in refrigerating temperature. The other group is precooked breadcd and precooked breaded stored in refrigerating temperature and one group served as contl-01- frozen (unbreaded). All samples are subjected to organoleptic test based on the eye appeal, palatability '~r~d texture.

3. RESULTS AND DISCUSSIONS 3.1 Smoked product The approximate chemical analysis of fresh and smoked carp is :

Mois- Pro- tttre tein Ash FII

~resh ... 77.88 Is.99 0.9j 3 42 Smoked ... 77-12 21.12 I .91 3 42

Table I shows the quality data obtained from smoked carp stored at 5.C to 7°C.

From the results of the subjective tests based on the colmr, odour, texture and flavour, smoked citrp stored at room temperature, exposed or sealed, with precooking in brine and without precooking, skews that on the third day of storage it was already spoiled, while those stored at refrigerating temperature wjch tlx same conditions shows that on the 28th day of storage, samples were still edible with an average score of 7.0 to 6.0 which is equivalent to moderately-liked to slightly-liked. On its 44th day of storage, all samples are spoiled.

3.a Packaged and frozen sticks From the three diffxent packaging materials used in the freezing of carp sticks, results show that samplcs packed in polyethylene bags still are considered fresh after the 126th day of storage (see Table 2). T 58 3.3 Breaded carp prepared from frozen sticks

Tables j,4 and I show that frozzn raw breaded carp sticks aftcr thc 8znd day of stosagc have an average score of 6.0 b~sedon the eye appeal, palatability and texture which is equivalent to slightly-lrked, while those stved in refrigerators havc an average score of 6.9 to 5.g in tlescending order from slightly-liked to neither- liked nor disliked.

On the other hand, samples which arc precooked and froz-n show that on the 8znd day of storage, all are already rancid and spoiled and refrigeratccd precooked samples were all spoiled by the 33rd day of stxage.

4. CONCLUSION

Carp like most fish is a good protein source and could compare favourably with that of beef, pork and poultry. It may be processed in the snmc manner as other big fishes. It can be utilizd in many ways, making it accepted as a prime food commodity with a good product image.

Carp could be smoked, filleted and stored as frozen products and can be uscd as raw material for the preparation of convenience items. TABLE 1 TASTE PANEL SCORE RATING COLOUR, ODOUR, TEXTURE AND FL4VOUR OF SMOKED .4ND REFRIGERATED CARP. EXPOSED AND SEALED

SMOKED CARP REFRIGERATFD - --. -. - -. -- With precooking in brine Without precooking - - No. of days EXPOSED SEALED EXPOSED SEALED stored ------.- - Eye Palata- Tex- Eye Palata- Tex- Eye Palata- Tex- Eye Palata- Tex app~al biy :ure upped bility ture appzal bility ture appeal bility ture

.------. . 2 - - . . ------. Initial ...... 7.8 8.0 7.4 7.9 8.0 7.6 7.7 7.4 7.0 7.7 7.4 7.0

- . . . ------. .- . - .- -.. .. . -. ------36 ...... 5.0 5.2 5.0 Spoiled 3.8 3.8 3 .O Spoiled

TABLE 2 ORGlNOLEPTIC ASSESSMENT OF FROZEN CARP USlNG DIFFERENT PACKAGING MATERIALS

Aluminium foil Cotrite Polyethylene bag - No. of days Eye Pc laia- Tex- Eye Palcta- Tex- Eye Pulda- Tex- stored appral bility ture appeal bilitv ture appzal bility ture --- -- .... - Initial ... 8.5 7.9 7.0 7 ... 7.0 7.8 7.5 30 ... 7.0 7.7 7.0 44 ... 7.0 7.6 7.5 58 ... 7.0 7.5 7.0 72 ... 7.0 7.5 7.0 86 ... 7.0 7.0 7.0 100 ... 7.0 7.0 7.0 114 ... 6.5 7.0 7.0 128 ... 6.5 7.0 7.0 TABLE 3 ORGANOLEPTIC TFST OF FROZEN BREADED RAW CARP STICKS AND REFRIGERATED BREADED RAW CARP STICKS

Frozen breaded raw Refrigerated breaded raw

No. of days Eye Palata- Texture Eye Palata- Texturr stored upped bility appeal bility

8.0 7.0 5.5 spoiled

TABLE 4 ORGANOT,EPTTC TEST OF FROZEN PRECOOKED BREADED CARP STICKS AND REFRIGERATED PRECOOKED BREADED CARP STICKS

Frozen precooked breaded Refrigerated pnecooleed breaded

No. of days PaPa[ata- Texture Eye Pahta- Texfure stored hiliry appeal bility ------. - - -- .- 0 7.4 7.2 11.4 8.4 7.2 8.0 12 7.4 7.0 7.4 7 .O 7.0 7 .O 2 5 7.5 7.0 7.3 6.4 5.8 6.2 32 7.0 7.0 7.0 spoi!ed 40 7fi 7 .o 7 .o 53 7 .O 7 .O 7.0 63 4.5 6.8 6.0 82 rancid and spoiled

TABLE 5 CONTROL-FROZEN CARP STICKS

No. of days EY e Palctta- Texture stored appeal bility -- 8.0 8.0 7.3 7.4 6.7 6.5 6.2 6.0