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.

Observations on the fouling characteristics of four bryozoans in Cochin harbour

The occurrence of the four species of bryozoans under study showed that Electra crustulenta PALLAS and Victorella pavida KENT are brackish water forms, Electra bengalensis stoliczka and Schizoporella cochinensis Menon and Nair are typical marine forms. It is interesting to note the seasonal succession of these species in Cochin harbour correspond to the distribution of salinity in this area.

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.

Morphological, biochemical and growth characteristics of Serratia strains isolated from sardine (Sardinella longiceps)

Two aerobic, gram-negative asporogenous, red-pigmented, rod-shaped bacterial strains were isolated from oil sardine (Sardinella longiceps). Their morphological, biochemical and growth characteristics are reported. The pigment was identified to be a prodigiosene. The strains were found to resemble Serratia plymuthica. Effect of temperature and certain carbohydrates on pigmentation was also studied. Iron was found to inhibit pigmentation, and mannitol or sorbitol removed such inhibition.

Freeze drying of fishery products: Part V - Storage characteristics of ready-to-serve freeze dried foods

Behaviour of freeze dried ready-to-serve fish based food preparations during prolonged storage at room temp has been studied and reported in this paper. Storage life of such products under the conditions employed in this study can be reckoned in years at our ambient temps.

Electrophoretic characteristics of oil sardine (Sardinella longiceps) and mackerel (Rastrelliger kanagurta) eye lens proteins

Electrophoresis of eye lens proteins of oil sardine and mackerel showed separation of proteins into three and four components, indicating the heterogeneous nature of the population.

Freezing characteristics of tropical fishes III. Spotted seer (Scomberomorus guttatus)

Skin-on fillets of spotted seer were frozen individually with different pre-freezing ice storage periods, and stored at -23°C and -l0°C. The frozen storage shelf life was evaluated, with respect to holding time in ice prior to freezing, by examining the extent of oxidative rancidity, protein denaturation, organoleptic changes etc. Fillets with pre-freezing ice storage periods of 0, 3, 5 and 7 days had frozen storage shelf-life of 32, 24, 20 and 16 weeks respectively at -23°C. The fillets stored in ice for more than 7 days are unsuitable for further processing. Storage temperature greatly affected keeping quality of frozen fillets. Freshly frozen fillets stored at -10°C became unpalatable at 16-20 weeks as compared to 28-32 weeks for the fillets stored at -23°C.

Ice storage characteristics of perch with special reference to its suitability for canning

Perch (Pagrus spinifer), one of the most abundantly available fishes of Gujarat coast, was subjected to a detailed study for assessing its storage life in ice and amenability of the iced fish for canning. Changes in the salt soluble nitrogenous material and myosin content of the iced fish showed good correlation with the changes in the organoleptic and physical qualities. The fish was found to have a storage life of 9 days in ice and samples stored up to 7 days were suitable for canning.

Studies on the ice storage characteristics of blood clam Anadara granosa meat

Ice-storage study of blood clam (Anadara granosa) meat in direct contact and out of contact (in 200 gauge polyethylene bag) with ice was taken up to assess the amenability of the meat to icing. Changes in moisture, total protein, non-protein nitrogen, α amino nitrogen, total volatile base nitrogen, glycogen, free fatty acid, peroxide value, total bacterial count and coliform count were followed every day. The raw and cooked meat were also subjected to organoleptic evaluation. The study showed that the clam meat can be ice-stored in very good condition out of contact with ice in polyethylene packets for 4 days and in direct contact with ice for 2 days.

Studies on frozen storage characteristics of sole fish Cynoglossus macrolepidotus

Fresh sole fish (Cynoglossus macrolepidotus) was quick frozen at -40°C and stored at -18°C. Shelf life was evaluated by following biochemical, bacteriological and organoleptic changes occurring during storage. Rapid decrease was noted in the water extractable nitrogen and salt soluble nitrogen fractions. Samples of frozen sole fish remained in acceptable condition for 20 weeks.

Settlement characteristics of Crassostrea madrasensis in the Cochin backwaters

Settlement pattern of Crassostrea madrasensis (Preston) at five different habitats in and around Cochin Harbour is reported. The settlement pattern is found to be considerably influenced by the distribution of salinity at the various locations. Peak settlement occurred when salinity ranged between 22.4‰ to 33‰.

Development and storage characteristics of dehydrated salt mince from low priced fish

The study showed that less initial moisture with high salt content will be the best condition for enhanced storage life of dehydrated salt mince. Between sample I (10% salt per meat weight) and sample II (15% salt per meat weight) the latter was comparatively better in colour, odour and longer shelf-life. At room temperature the dehydrated salt mince has not showed any increase in total bacterial count. It is also found that the storage life of the salt mince can be enhanced to a significant extent by lowering the moisture content to below 10% and increasing the salt content to above 30%. Peroxide value, free fatty acid value, total volatile nitrogen and trimethylamine registered gradual increase during storage at room temperature for all the three samples. Among the three samples, the sample treated with 0.1% citric acid and 0.125% butylated hydroxy anisole was comparatively better in appearance and showed less rancidity as indicated by TBA values, up to a period of 15 weeks and thereafter all the three samples were almost similar in storage characteristics. Hence, the treatment with citric acid and B.H.A. has apparently not much significance in improving shelf-life and quality of salted dehydrated fish mince.

On the ice-storage characteristics of Catla catla and Labeo fimbriatus

The ice-storage characteristics of Catla catla and Labeo fimbriatus are reported. Muscle pH, moisture, total volatile nitrogen, alpha amino nitrogen and peroxide value and also the changes in total bacterial count are studied. C. catla and L. fimbriatus both could be stored in ice for 18 days.

Studies on frozen characteristics of individually quick frozen and block frozen mackerel

Studies on mackerel (Rastrelliger kanagurta) of medium (4%) and high (11%) lipid contents quick frozen individually (IQF) and as blocks (BF) and stored at -23°C showed that block frozen mackerel had higher frozen storage shelf-life than individually quick frozen samples. IQF samples of medium and high lipid contents had shelf-lives of 17 and 20 weeks whereas BF samples of both series had 23 and 24 weeks respectively based on sensory evaluation.

Quality characteristics of cured fish of commerce

A survey was conducted at the fish curing yards at Shakthikulangara (Quilon), fish market at Vizhinjam, fish curing yards, fish market as well as dry fish godowns in and around Tuticorin. A total of 23 samples of different varieties of fishes collected from the markets and curing yards and 8 samples of anchovies collected from different godowns at Tuticorin were analysed to evaluate the quality and extent of fungal and insect infestation. Samples were analysed for proximate composition and estimated their water activity. About 70% of the 23 samples of different varieties of fish were found to be unfit for consumption and 12.5% of the samples of anchovies were found to be infested with beetle, after 3 weeks of storage after collection from these centres.