Freezing characteristics of tropical fishes 2. Tilapia (Tilapia mosambica)

Tilapia from fresh water and brackish water-sources behaved differently during iced and frozen storage. The former showed an ice storage shelf life of about 13 days while the latter showed signs of spoilage beyond 10 days. In their respective freezing characteristics, the samples from the two sources exhibited far more significant variations. The fresh water type iced for 13 days preserved well for over 24 weeks when frozen and kept at a temperature of -18° C, while the brackish water variety held in ice for 10 days and subsequently frozen gave a shelf life of only 8 weeks under similar conditions.

Prices on Indian frozen shrimp in U.S. market: a note on seasonal variation

The supply and consumption of shrimp follow a more or less regular seasonal pattern. Like agricultural products, fishery products have also their period of heavy and less productions on which depend their price movements. The prices of shrimp in any particular market reflect this seasonal behaviour quite often.

Utilization of sardines

Oil sardine Sardinella longiceps stands out as the single largest pelagic fishery in India contributing to about 30% of total marine fish landings. Commensurate with the volume of the fishery, efforts at proper utilization of the fish by processing into canned and frozen products or by distributing in fresh state to internal consuming centres by quick transport have remained rather very poor. The paper presents the problems and prospects with regard to the utilization of the fish on the above lines. Results of investigations made at C.I.F.T. on the utilization of sardine body oil into industrially useful products such as factice, vehicle for paints, additive in lubricating oil and base for printing ink have also been discussed.

Preliminary studies on freezing characteristics of Bombay duck (Harpodon nehereus)

Fresh Bombay duck (Harpodon nehereus) can be quick frozen at -40°C and stored at -l0°F for about 3 months in a very fair and acceptable condition. The maximum drip loss observed was about 24%. Rapid decrease in the extractable protein nitrogen of the fish muscle was noted during the frozen storage.

Technological aspects of preservation and processing of edible shell fishes IV. Comparative efficiency of different glazes in the preservation of frozen crab meat

The present work was undertaken to enlighten upon the comparative efficiency of different glazes in improving the quality of frozen crab meat (Scylla Serrata).

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.

Studies on thermal deffusivity [i.e. diffusivity] and conductivity of fresh and dry fish

Thermal diffusivity (α) and conductivity (K) of fresh and dry cured fish at different moisture levels were investigated by a calorimeter (regular regime) method and transient line source technique. Thermal conductivity has a linear correlation with packing density and percentage water content. K values calculated from formula method and line source technique are comparable.

Lipid hydrolysis in mackerel (Rastrelliger kanagurta) during frozen storage

The hydrolytic changes in the lipids of mackerel (Rastrelliger kanagurta) during storage at -l8°C were studied with a view to understand the factors involved in the formation of free fatty acids. Only the phosphorylated fraction did undergo hydrolysis at an appreciable rate. It was found that the free fatty acid production was mainly associated with the phospholipid hydrolysis. As regards the triglycerides and unsaponifiable matter, there was no significant change in levels during frozen storage.

A statistical study on weight loss in frozen prawns

This paper deals with an extensive study conducted to estimate the extent of weight loss in frozen prawns. The weight Joss varied from 7 to 12% in peeled and deveined (PD), 5 to 7% in headless (HL) and about 7% in cooked and peeled (CP) prawns from the date of processing to the date of inspection, normally within two weeks. To compensate the weight loss nearly 11% of excess material is being added with every frozen block resulting in an average annual loss of Rs. 2.68 crores in foreign exchange. The relevant data pertain to the period 1971 to 1973 and the annual average loss was estimated for the ten years ending 1973.

Bacterial flora of fresh and iced Indian mackerel (Rastrelliger kanagurta) and its response to chlortetracycline (CTC) treatment

Quantitative and qualitative studies on the bacterial flora of fresh Indian mackerel (Rastrelliger kanagurta) have been made. The total native flora as well as 5 ppm CTC insensitive flora of the fish showed variations with season. About 90% of the fresh fish flora was sensitive to 5 ppm CTC. The natural flora of the fresh fish consisted of Vibrios, Pseudomonas, Achromobacter, Flavobacterium, Corynebacteria, Micrococci, Bacillus and yeasts. In the CTC insensitive flora, Vibrios predominated followed by yeasts. The selection of bacterial genera during storage of the fish in ice and in 5 ppm CTC incorporated ice has also been investigated. At the time of spoilage, Pseudomonas was found to be the dominant flora of the fish stored in both types of ice.

Iced and frozen storage of squid (Loligo sp)

The iced and frozen storage characteristics of squid (Loligo sp.) are discussed. Squid can be kept in ice in an acceptable condition for a maximum period of 2 days. Frozen squid can be stored for a maximum period of 15 weeks at -l8°C, which can be extended up to 19 weeks by suitable treatment.

Investigations on long distance transportation of fish 1. Transportation of frozen fish from Cochin to Calcutta

Oil Sardine (Sardinella longiceps), mackerel (Rastrelliger kanagurta), cat fish (Arius sp.), threadfin bream (Nemipterus japonicus) and ribbon fish (Trichurus sp.) were frozen in glazed/unglazed blocks, packed in expanded polystyrene (EPS) insulated plywood boxes with and without additional ice and despatched in uninsulated parcel vans of trains from Cochin to Calcutta. The consignments reached the destination in excellent condition and were readily disposed off.

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.

Studies on frozen storage of ghol (Pseudosciaena diacanthus)

Investigations were carried out on the frozen storage of ghol (Pseudosciaena diacanthus) in the form of fillets. The results indicated that ghol fillets stored at -l8°C remained in a highly acceptable condition up to 20 weeks. However, after this stage, the acceptability steeply declined.

Studies on frozen storage of minced fish from threadfin bream

Minced fish prepared from threadfin bream (Nemipterus japonicus) was frozen as blocks, packed in polythene lined waxed cartons and stored at -23°C. The changes taking place during storage were followed. There was good correlation between the organoleptic quality, extractability of protein, cook drip loss and weight loss on thawing. The frozen minced fish was acceptable up to 28 weeks under frozen storage.