Combined Effect of Antifreeze Peptides and Transglutaminase on the Frozen Storage Stability of Surimi Gel

To enhance the frozen storage stability of surimi gels cross-linked with transglutaminase (TG), the synergistic effect of silver carp scale-derived antifreeze peptides (ScAFPs) combined with TG cross-linking on the texture properties, gel characteristics, whiteness, drip loss, morphology, and microstructure of surimi gels was investigated during frozen storage. The results demonstrated that TG promoted the formation of a compact gel network through cross-linking myofibrillar proteins, while ScAFPs effectively inhibited structural deterioration caused by ice crystal growth during frozen storage. Texture profile analysis revealed that the combination of 2.0% ScAFPs and 0.05% TG resulted in smaller variations in gel hardness, elasticity, and strength after 28 days of frozen storage compared with 0.05% TG alone and a commercial antifreeze formulation (4.0% sucrose + 4.0% sorbitol). The synergistic treatment reduced whiteness loss by 37.50% and decreased thawing drip loss by 63.25% compared with the control group. Microstructural analysis indicated that the combination of ScAFPs and TG effectively suppressed ice crystal growth, reducing the increase in ice crystal porosity by 48.50% compared with the control group, while mitigating gel shrinkage and surface collapse. This study helps to understand the mechanism by which ScAFPs synergize with TG to stabilize surimi gel quality during frozen storage, providing both a theoretical foundation and technical pathway for developing novel frozen surimi products.