Preservation and Processing of Aquatic Products

   The preservation and processing of aquatic products are crucial aspects of fishery production, playing a significant regulatory role in the development of fishing operations. Advancing preservation and processing technologies can effectively support and promote the growth of both capture and aquaculture industries, holding great importance in China's fishery development.

Principles of Aquatic Product Preservation

 The activity of autolytic enzymes and microorganisms in fish is influenced by temperature. Below 10°C, many bacteria cease to reproduce. At 0°C, even psychrophilic (cold-adapted) bacteria grow very slowly. Common preservation methods include:

• Refrigerated air preservation (0–5°C)
• Ice chilling (using crushed or flaked ice)
• Partial freezing (superchilling) methods (e.g., ice-salt mixtures, chilled brine/seawater, or freezer-based partial freezing)
• Modified atmosphere packaging (MAP) with low-temperature preservation

Principles of Freezing Aquatic Products

 Freezing reduces water activity, controls microbial growth, inhibits enzyme activity, and prevents non-enzymatic changes such as lipid oxidation, ensuring product quality. At -18°C, ice crystals form within the tissue. Common freezing methods include:

• Brine freezing (contact and non-contact methods)
• Air freezing (using air as a cooling medium, the most common method)
• Contact (plate) freezing (conducted with plate freezers, available in vertical and horizontal configurations)
• Individual quick freezing (IQF)