VPP 322: Aquatic Animal Diseases, Health Care and Management (1+1)

FREEZING OF FISH

• Freezing is one of the most important method of preservation of fish. During freezing process, the temperature of fish is lowered below -1^oC so that most of the water present in fish is converted into ice and the fish is preserved for longer periods without deterioration. Various types of freezing methods that are followed for freezing preservation of fish are , freezing in cold air, Tunnel freezing (using cold blast of air at -35^oC to -40^oC), freezing with liquefied gas (nitrogen, carbon-di-oxide), contact freezing (using plate freezers), freezing with rotary drum, Immersion freezing (freezing in brine) and freezing with liquid refrigerant -12( dichlorodifluoro methane). Whole fishes, fish chunks (large fish are cut into small pieces or chunks), shell fishes like shrimp, prawn, crab meat, lobster, clam, mussels, squids and cuttle fishes are frozen for long storage and exported.