Synergistic antioxidant action and enhanced digestive utilization of Corbicula fluminea protein enabled by binding to epigallocatechin gallate

To expand the application of Corbicula fluminea protein (CFP) as nutritional antioxidant, epigallocatechin gallate (EGCG) was employed to form physically and chemically bonds with CFP. The effects of varying EGCG concentrations and binding types on the interaction mechanism as well as particle properties, antioxidant activity, and bio accessibility of CFP was thoroughly investigated. The findings revealed that physical modification resulted in larger non-covalent complexes primarily maintained by hydrophobic interactions. In contrast, chemical modification led to tighten covalent complexes with smaller particles. Although both physical and chemical modifications improved CFP's antioxidant activity, non-covalent complexes showed superior antioxidant capacity with EGCG exerting a more marked synergistic effect on CFP, particularly at lower concentrations. Furthermore, both EGCG-CFP complex types exhibited enhanced bioaccessibility and gastrointestinal digestive antioxidant activity, with these advantages being more prominent in the non-covalent form. This work would supply valuable insights for broadening the complexes as high nutritional antioxidant. • Non-covalent binding to low EGCG concentrations exhibited synergistic effects. • The underlying interacting mechanism was explored. • His and Met may serve as the binding sites for covalent interaction. • EGCG partially inhibited CFP hydrolysis and enhanced its bioaccessibility.