Cryoprotective effect of glycopeptide complex from abalone viscera on frozen surimi and its underlying mechanism

Abstract Freezing technology is important for the long‐term preservation of aquatic products such as surimi. However, mechanical damage caused by ice crystals would lead to quality deterioration. Abalone viscera glycopeptide (AVGP) complex was prepared by hydrolysis technology, which exhibited ice recrystallization ability and antioxidant activity. Moreover, effects of AVGP on Ca 2+ ‐ATPase activity, total sulfhydryl content, secondary structure of myofibrillar protein (MP), rheological properties, and gel properties of surimi frozen were investigated. Results showed that surimi treated with AVGP could improve the gel strength and rheological properties of surimi, reduce the gel ice crystal holes, and improve the degradation of gel matrix caused by freeze–thaw. AVGP can significantly inhibit the decrease of Ca 2+ ‐ATPase activity and total sulfhydryl group content. When the addition of AVGP exceeded 4% (w/w), its freezing protection effect on MP was better than that of commercial antifreeze agents. Moreover, the α‐helix and β‐fold contents in the 4% AVGP group were significantly higher than those in the control group, indicating that the addition of an appropriate amount of AVGP can protect the secondary structure of MP. Therefore, AVGP could serve as a new food ingredient with antifreeze and antioxidant functions for frozen surimi.