Physical preservation technology and application of aquatic products

Aquatic products are characterized by rich nutrition and easy deterioration. During the storage and fresh-keeping process of aquatic products, the deterioration of aquatic products will not only affect the quality, but also produce toxic substances, bringing safety problems to consumers. Therefore, the storage and fresh-keeping technology of aquatic products is an important link in the processing and marketing of aquatic products. Choosing appropriate storage and fresh-keeping technology can not only ensure the quality and safety of aquatic products, but also ensure the good taste, texture and flavor of aquatic products, and protect aquatic product resources. Therefore, it is of great significance to study the fresh-keeping technology and improve the fresh-keeping system of aquatic products. This paper mainly introduces the research and application progress of low temperature preservation technology and modified atmosphere preservation technology.
Overview of physical preservation technology for aquatic products

The physical fresh-keeping technology of aquatic products mainly includes low temperature fresh-keeping technology, modified atmosphere fresh-keeping technology and ultra-high pressure fresh-keeping technology. Low temperature preservation technology is to control the preservation of aquatic products at lower temperatures. It is a widely used method for preservation of aquatic products. As early as ancient China, people used natural freezing or natural ice and snow to preserve aquatic products at low temperatures.
The principle of low temperature preservation is firstly that low temperature will reduce the activity of metabolic enzymes in microorganisms, increase the concentration of protoplasts, increase the viscosity, and produce ice crystals, which will have a great impact on microorganisms; Secondly, low temperature will reduce the speed of chemical reaction of enzyme activity and slow down the process of deterioration of enzymes on aquatic products.
Aquatic products are generally stored and kept fresh at low temperature, including 0~4 ℃ cold storage, 0~- 2 ℃ ice temperature, – 2 ℃~- 4 ℃ micro freezing and – 18 ℃~- 40 ℃ freezing. The modified atmosphere fresh-keeping technology is widely used in the fresh-keeping of other agricultural products. The modified atmosphere fresh-keeping technology has a good effect on aquatic products. It is rated as the most effective fresh-keeping technology for aquatic products. The ultra-high pressure fresh-keeping technology is less used in the production and processing of aquatic products because of its high operating cost.