The term of possible storage or transportation of the cooled fish even if to use the newest methods of its complex processing (simultaneous impact on fish of cold and an antibiotic, and the frozen fish extremely limits possibilities of supply of the population of the extensive country with the fresh cooled fish. This term is absolutely insufficient for preservation and transportation of the fish raw materials intended for secondary processing at the enterprises located within the country and also for preservation of fish of the remote oceanic trade. For considerable extension of periods of storage fresh fish has to be processed so that its natural properties remained the longest time. In such a way freezing is.
Distinction as production is that in the cooled fish are slowed a little down, but microbiological and fermentativny processes are not stopped, and in the frozen — proteolytic and microbiological processes are completely stopped.
Ways of cooling and freezing of fish and other seafood are very various, but on character of the cooling environment they can be divided into two groups: to the first group ways of cooling in the homogeneous environment (for example, cooling of fish in cold air or cold liquid), belong to the second group — ways of cooling of fish in ice. Cooling of fish in air minus of 2-3 degrees is applied by temperature very seldom as in these conditions fish is cooled slowly and, both when cooling, and at the subsequent storage, her trade dress worsens. The most widespread ways of industrial cooling of fish are cooling with immersion of fish in the cold liquid environment, cooling with an irrigation of fish with a cold brine and cooling with shredded ice. From these ways cooling with shredded ice, and least — by an irrigation is most extended by a brine.
At storage of the glazed fish evaporation of water happens from an ice crust surface. The mass of ice decreases, and after a while its contents will be less than standard 4%. Regulations of Admission of frozen fish allowed existence of 2-4% of glaze.
Storage conditions have to provide invariable the chemical composition and histologic structure of tissues of fish received as a result of freezing. For this purpose temperature in a left-luggage office is maintained to a constant and equal temperature in the center of fish.