Effects of Hydrogel-Forming Composite Cryoprotectants on the Quality of Frozen Freshwater Crayfish (Procambarus clarkii).

The use of a composite cryoprotectant to maintain the quality of freshwater crayfish (Procambarus clarkii) during frozen storage was investigated in this study. Chitosan (CTS) and carrageenan oligosaccharides (CG) are natural hydrogel-forming polysaccharides that serve as moisture barriers. The effects of different concentrations of CTS (0-1.5%), CG (0-1.0%), antifreeze proteins (AFPs, 0-0.25%), and tea polyphenols (TP, 0-0.03%) on crayfish muscle tissue were evaluated by measuring water-holding capacity (WHC), total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS). Based on single-factor experiments, a three-factor, three-level response surface methodology (RSM) was applied with WHC as the response variable. The results showed that a maximum WHC of 71.65 ± 0.46% was obtained under the optimal treatment, comprising 0.81% CG, 0.61% CTS, and 0.17% AFPs. This study provides a theoretical basis for developing composite cryoprotectants and frozen pre-cooled products from freshwater crayfish, as well as a reference for the application of polysaccharide-based hydrogels in aquatic product frozen preservation.