Abstract:This study aims to explore the effect of polyphenols on the side chain structure of pork myofibrillar protein.Different concentrations（0，0.1，0.2，0.5，1.0 and 2.0 mmol/L）of epigallocatechin gallate（EGCG）were added into the hydroxyl radical oxidation system.The untreated myofibrillar protein was used as the control group.The effects of EGCG on the side chain structure and gel water distribution of myofibrillar protein were determined.The results showed that EGCG decreased the content of free sulfhydryl and total sulfhydryl，which was lower in the 0.1 mmol/L-2.0 mmol/L groups than in the blank control group （P＜0.05）.EGCG，especially at the concentration of 2.0 mmol/L，decreased the content of carbonyl and dityrosine.EGCG increased the storage modulus （G'）of the protein gel in a concentration-dependent manner.Moreover，it increased the water holding capacity （WHC）of the gel，as manifested by the increased immobilized water and decreased free water in the gel，and 2.0 mmol/L EGCG demonstrated the best performance.The correlation analysis showed that EGCG concentration was negatively correlated with the carbonyl content，free amino content，and surface hydrophobicity of the protein （P＜0.01）.The WHC of the gel was negatively correlated with the free and total sulfhydryl content，carbonyl content，and surface hydrophobicity of the protein（P＜0.01）.