Effect of Cold Chain Storage on Chemical Interactions of Surimi Gel and Structural and Functional Properties of Myofibrillar Protein

In order to study the effect of cold chain storage on the structural and functional properties of myofibrillar protein and the chemical interactions of surimi gel, the changes in the functional groups and secondary and tertiary structure of myofibrillar protein and the chemical interactions of surimi gel were investigated as a function of cold chain storage time, and the relationship between chemical interactions and myofibrillar protein was evaluated by principal component analysis (PCA) and correlation analysis. Results showed that the salt-soluble protein content, Ca²⁺-ATPase activity and total sulfhydryl content in surimi gel decreased, while the carbonyl content increased during storage. In addition, the secondary structures of myofibrillar protein transformed from an ordered to a disordered state, and the fluorescence intensity decreased, indicating changes in the polar environment of the protein. These findings demonstrate that the active groups in myofibrillar protein are closely related to the formation of gel chemical forces. Therefore, preventing protein oxidation and freeze denaturation at the initial stage of storage is an effective way to maintain the chemical interactions of surimi gel and the gel characteristics. This study can provide basic theoretical support for the quality maintenance of surimi during cold chain storage.