Physical Preservation Technologies and Applications for Aquatic Products

　　A hallmark of aquatic products is their rich nutritional value; at the same time, they are highly susceptible to spoilage. During storage and preservation, spoilage not only degrades product quality but can also generate toxic compounds, posing safety risks to consumers. Consequently, effective storage and preservation technologies are critical components of the processing and marketing of aquatic products. Selecting appropriate methods ensures both product quality and safety, while preserving desirable sensory attributes—such as taste, texture, and flavor—and safeguarding aquatic resources. Therefore, research into preservation techniques and the refinement of comprehensive preservation systems are of paramount importance. This paper primarily reviews recent advances in the research and application of low-temperature preservation and modified-atmosphere preservation technologies.

　　Overview of Physical Preservation Technologies for Aquatic Products

　　Physical preservation technologies for aquatic products primarily include low-temperature preservation, modified-atmosphere preservation, and ultra-high-pressure preservation. Low-temperature preservation involves maintaining aquatic products at reduced temperatures; it is one of the most widely used methods for preserving such products. As early as ancient China, people employed natural freezing or ice and snow to achieve low-temperature preservation of seafood.

　　The principle underlying low-temperature preservation is that, first, cold temperatures reduce the activity of metabolic enzymes within microorganisms and increase the concentration of protoplasm, thereby raising its viscosity; coupled with the formation of ice crystals, these factors exert significant adverse effects on microbial cells. Second, low temperatures slow down enzyme‑catalyzed chemical reactions, thus decelerating the enzymatic spoilage of aquatic products.

　　Low-temperature storage and preservation technologies for aquatic products are generally categorized into four types: refrigeration at 0–4°C, ice‑temperature preservation at 0 to –2°C, mild freezing at –2 to –4°C, and frozen storage at –18 to –40°C. Modified‑atmosphere preservation is widely employed for other agricultural products; when applied to aquatic goods, it delivers excellent results and has been recognized as the most effective preservation method. By contrast, high‑pressure processing, due to its relatively high operating costs, sees limited use in the production and processing of aquatic products.