Freshwater fish preservation technology

The fresh-keeping technology of aquatic products widely used for frozen processing of freshwater fish is basically two categories, cooling and preservation, and freezing and preservation. Cooling and fresh keeping has made new progress on the basis of the 70s. The basic forms are as follows:

1. Radiation preservation is a fresh-keeping technology that uses r-rays or cobalt 60 to sterilize foods.

2. Container preservation is mostly used for on-board and onshore storage and transportation. It is divided into cold storage and self-contained refrigeration.

3. Gas Replacement Packaging Preservation is the replacement of oxygen with carbon dioxide or oxygen to suppress bacterial growth and prevent fat oxidation.

4. Fresh-frozen preservation is a fresh-keeping technique for fish at a temperature range of -2 to -5°C. The preservation period is approximately 20 to 27 days.

5. Ice temperature preservation is a technique for preserving foods in a non-frozen state by using different ice points of various foods and in a negative temperature range below 0°C. (0～-1°C preservation period 7-10 days).

6. Freezing preservation is to freeze fish products below -18°C, inhibiting bacterial growth and achieving longer-term preservation. The new technologies that are currently applied include low-temperature preservation, ultraviolet light, ozone and cooling, preservation, or separate use of sterilization and preservation methods, and calcium chloride brines used in Japan are frozen and preserved. In general, frozen preservation is mainly used in several methods such as blow freezing, contact freezing, spray freezing and immersion freezing.

The frozen processing of freshwater fish can be installed in the production of small-scale refrigeration equipment for production, is conducive to achieving raw materials, good quality, less pollution, easy to wash, freeze and fast refrigeration quality requirements, to ensure the strict implementation of operating procedures and food hygiene law.