Bacterial aspects of quality of phosphate treated frozen prawns

Changes in physical, organoleptic and biochemical characteristics of phosphate treated prawns and frog legs during storage have been studied in detail by Mathen and Pillai, (1970). Adoption of the recommended method by the industry in the freezing of prawns made it necessary to assess the influence of such treatment on the bacterial quality. This aspect assumes more importance in view of the proposed compulsory bacterial standards for raw frozen prawns. This note gives an account of the results on the influence of phosphate treatment on bacterial quality of raw frozen shrimp meat.

On the measurement of concentration of blanching brine by electrical conductivity method

Blanching is an important operation in the shrimp canning process, in order to bring down the moisture content of the product to the required level, to allow the proteins to coagulate and to give proper texture, shape and characteristic pink colour to the meat. It has been observed that among other factors responsible for fluctuations in the drained weight in the canned prawns, concentration of brine used for blanching and the duration of blanching are important (Varma, Chaudhury and Pillai 1961). The papers gives details of experiments

A review on oil sardine 2. Preservation by canning, curing and smoking

Commercial canning of oil sardine (Sardinella longiceps) in India is a relatively new procedure. Although 7 firms are engaged in canning this compares poorly with the abundance of the fish. There are often wide variations in the quality of the canned fish and important chemical and physical variations occur in the product once canned. A description of the canning process is given, and production figures compared to those of other countries. Production figures for 1965 to 1969 are given. These show that production increased from 1.2 to 1.5 million cans, but that there was a peak in 1967 when 3.2 million can s were produced. Exports of canned marine fish by country, and production of caned sardine by country from 1965 to 1970 are tabulated. The types of containers used and the feasibility of exporting canned fish are considered. Finally, the preparation of cured and smoked products is discussed briefly.

Studies on smoke curing of tropical fishes

Fresh mackerel (Rastrelliger kanagurta), catfish (Tachisurus dussumeri) and sole (Cynoglossus dubis) were gutted, cleaned, washed, brined, and smoked. Though it contributes to the quality of the smoked products, salt does not appear to prevent bacterial growth or spoilage at low concentration. In heavily salted products, salt is found to have a definite preservative action. Smoking lasted roughly 5 hrs for mackerel and 4 hrs for sole. Increasing the smoking time gave the product an unpleasant taste. Fish were then sun-dried to 20% moisture. The fish had been prepared in three groups, (1) turmeric-treated, (2) propionate-treated and control. Turmeric treated samples had a very attractive appearance, especially sole. The course of spoilage, as measured by following changes in total volatile nitrogen content, is tabulated. All controls were spoiled within 3 months; the others remained in good condition for 6 months. Turmeric is considered to be an ideal preservative.

Chitosan from Squilla

Squilla (Oratosquilla nepa) is abundant along the west coast of India, inhabiting burrows in sand and mud. The species is little used as it possesses little meat. There is great similarity between chemical composition of Squilla and prawn waste, and it is suggested that Squilla could therefore be used for making chitosan, a potential industrial chemical with various uses. Preparation of chitosan, and the general nature of the prepared product, is described.

Studies on mollusca of Saurashtra coast - I. (Amphineura and Gastropoda)

Proximate composition of 19 species of marine Gastropoda and one of marine Amphineura have been studied. Seasonal variations in proximate composition of the meat of gastropods, Thais rugosa (Born), are reported. Majority of the gastropod species have high protein and ash contents.

Studies on mollusca of Saurashtra coast - II. (Pelecypoda)

The paper deals with the proximate composition of Crassostrea graphoides, C. cucullata, Placenta placenta, Pinna vexillum, P. bicolor, P. atropurpurea, Solen truncatus and Pitar erycina. Seasonal variations in water, protein, salt and ash in the meat of C. graphoides, C. cucullata and P. placenta are reported. Percentage of meat is high in S. truncatus and low in C. graphoides, C. cucullata and P. erycina. Most of these species contain higher moisture than gastropods

Comparative evaluation of fish protein concentrate and functional fish protein concentrate from cat fish

Fish protein concentrate and functional fish protein concentrate samples were prepared from eviscerated meat of cat fish (Tachysurus jella Day). Functional fish protein concentrate is found to be lighter, less gritty and rehydrates more rapidly than fish protein concentrate. Functional FPC is seen to have higher PER and biscuits containing it at levels of 5 and 7 percent are less hard compared to FPC.

Development of partially hydrolysed and deodourised fish flour

A process developed for preparation of partially hydrolysed and deodorised (PHD) fish flour, without solvent extraction is described. The PHD fish flour prepared from four varieties of trash fish had creamy white colour and contained 87-92% protein and 7-8% available lysine. The products had shelf life of more than a year at room temperature, and caused no grittiness when incorporated in snacks and bakery products at 10% and 7.5% level respectively. The flour prepared from Nemipterus spp. had a PER 2.32 compared to 2.68 of raw fish meat and 2.5 of standard casein.

Studies on mollusca of Saurashtra coast - 3. Composition

The paper presents the seasonal variations in moisture, protein, salt and ash in the meat of Murex virgineus, Solen sp., Loligo sp., Sepiella inermis and Octopus sp. Moisture and fat contents of twenty two species of molluscs are reported. Inverse relationship between protein and ash has been observed. Cephalopoda recorded higher meat, moisture and protein contents than amphineura, gastropoda and pelecypoda. Pelecypoda contains higher fat than amphineura, gastropoda and cephalopoda.

Biochemical changes of fish fingers held at frozen storage

The frozen storage characteristics of fish fingers made out of two different species, differing in lipid content for a period of six months are outlined. The study reveals that the lipid content of the fish meat used for making fish fingers influences the storage pattern in terms of the chemical parameters like peroxide value, thiobarbituric acid value and free fatty acids. The introduction of monosodium glutamate has improved the flavour of the fish fingers. Further, the application of batter on the fish fingers imparted some protective effect in the case of semi-fatty fish.

Pickled products from green mussel

Methods of preparing different types of delicious ready to serve pickled products from green mussel (Perna viridis) and a comparative study of their storage characteristics are reported. Of the three types of products, namely, dried and pickled, fried and pickled and light smoked and pickled, the last one had the best shelf life. The optimum conditions of drying and smoking for preparing such type of pickles are also reported.

Studies on depuration of live clams (Villorita sp.)

Live clams collected from their natural beds were depurated by starving them in water. Water from their natural environment, potable water from municipal water supply and sodium chloride solution made up to the strength of natural brackish water as well as all these chlorinated at 5 p.p.m. level were used. The acid insoluble ash could be brought down to insignificant level by depuration in natural water for a period of 16-18 h. Bacterial quality of the meat also could be improved by this method. Chlorination of the system at the end of depuration further improves the bacterial quality of the meat.

Evaluation of organoleptic qualities of fish grown in ponds treated with different organic manures

Catla, rohu, silver carp and common carp raised employing different organic manures were subjected to organoleptic evaluation, both in raw and cooked form. The combination treatment of poultry manure and silkworm faecal matter had positive effect on colour and glossiness of skin and colour of flesh in the case of common carp. Though no significant difference was observed in the overall quality, odour of flesh and texture of meat of rohu were found to be better in sewage treated and poultry manure treated ponds respectively. From the results, it can be discerned that treated sewage has no adverse effect on the acceptable qualities of the carps studied.

Antibiotic sensitivity of Staphylococcus aureus strains isolated from fishery products

During the course of an investigation on the incidence of Staphylococcus aureus contamination in frozen crab meat, frozen prawns and dried fishes from Cochin, 116 strains of S. aureus were isolated. The sensitivity of the isolated strains towards nine antibiotics showed that all the S. aureus strains were sensitive to kanamycin and streptomycin (100%). Sensitivity to other antibiotics like chloramphenicol, polymyxin-B, erythromycin, tetracycline, neomycin, penicillin and ampicillin were shown by 98.28, 93.10, 87.93, 68.10, 67.24, 56.90 and 55.17 percent of the isolates respectively.