Study on the interactions of different tea polyphenols with goat myosin and their synergistic strategy for multifunctional enhancement

Goat myosin is a vital muscle protein dominating meat product quality and functional characteristics, yet its physicochemical properties and structural stability restrict large-scale industrial application. Polyphenols have been verified to optimize protein solubility, antioxidant capacity and other functional attributes. Therefore, this study hypothesizes that EGCG and EGC can interact with myosin, thereby modulating its structure and improving its physicochemical properties. Results demonstrated that both polyphenols are bound to goat myosin to form stable complexes. The secondary and tertiary structures of myosin were distinctly modified, accompanied by reduced α-helix proportion and concentration-dependently elevated random coil content, suggesting ordered structure unfolding toward disordered conformation. At 100 μmol/L, random coil contents were elevated by 15.52% for EGCG and 6.70% for EGC. Molecular dynamics simulations confirmed improved complex stability after polyphenol incorporation, with hydrophobic interaction and hydrogen bond as primary binding forces. At 80 μmol/L, the binding rates of EGCG and EGC reached 18.80% and 19.03%, respectively. At 100 μmol/L, their DPPH radical scavenging capacities reached 80.68% and 79.33%. Combined physicochemical characterization and in vitro digestion assays revealed that polyphenol-myosin interactions improved protein solubility and antioxidant activity but declined surface hydrophobicity and digestibility. EGCG exhibited stronger modification effects than EGC overall. This study provides theoretical support and practical industrial references for functional modification of goat myosin via tea polyphenol intervention.