In this study, the effects of different freezing methods namely air freezing, cryogenic freezing, freezing after dipping in a refrigerating medium consisting of 20% ethanol (V/V), 20% propylene glycol (V/V), 5 g/100 mL trehalose aqueous solution and freezing after dipping in anhydrous ethanol on the quality of sea bass were investigated. The results showed that the freezing rates of refrigerating medium freezing and anhydrous ethanol freezing were 8.20 and 6.25 cm/h, which were 32.80 and 25.00 times as high as that of air freezing, respectively. The microstructure of frozen sea bass showed that the small ice crystals formed between muscle tissues were small, and the muscle fibers were closely arranged. Refrigerating medium freezing was more conducive to maintaining the water-holding capacity (WHC) of muscle tissues and slowing down the migration of immobilized water, and had a significant effect on maintaining the freshness, texture properties and protein thermostability of fish fillets. In summary, refrigerating medium freezing can effectively slow down the quality deterioration of frozen sea bass. The results of this study will provide a theoretical and practical basis for improving the storage quality of frozen aquatic products.

Prepared aquatic products have recently shown a momentum of rapid development due to its convenience and easy availability. With the characteristics of high protein content, high water content, and neutral pH, prepared aquatic products are susceptible to oxidation, microorganisms, and endogenous enzymes, leading to flavor deterioration. With the continuous development of the prepared aquatic products industry, understanding the mechanism of flavor deterioration in prepared aquatic products is of great significance for their quality maintenance and flavor regulation. In this context, the mechanism of flavor deterioration in prepared aquatic products is reviewed herein from the perspectives of protein oxidation, lipid oxidation, microorganisms, and endogenous enzymes. Furthermore, the methods for the flavor regulation of prepared aquatic products through processing techniques, exogenous additives, and packaging methods are discussed. We expect that this review will provide a reference for the flavor maintenance of prepared aquatic products and the development of the prepared food industry.