Soy protein isolate ameliorate gel properties by regulating the non-covalent interaction between epigallocatechin-3-gallate and myofibrillar protein

This study primarily investigated the improvement of high-dose Epigallocatechin-3-Gallate (EGCG)-induced deterioration of MP gel by soy protein isolate (SPI) addition. The results showed that EGCG could interact with MP, SPI, and HSPI (heated), indicating the competitive ability of SPI/HSPI against EGCG with MP. EGCG was encapsulated by SPI/HSPI with high encapsulation efficiency and antioxidation, with antioxidant activities of 78.5% similar to 79.2%. FTIR and molecular docking results revealed that MP, SPI, and HSPI interacted with EGCG through hydrogen bonding and hydrophobic interactions. SPI/HSPI competed with MP for EGCG, leading to the restoration of MHC and Actin bands, alleviating the aggregation caused by EGCG and oxidation. Additionally, SPI/HSPI-E significantly reduced the high cooking loss (23.71 and 26.65%) and gel strength (13.60 and 17.02%) induced by EGCG. Hence, SPI competed with MP for EGCG binding site to ameliorate MP gel properties, thereby alleviating the detrimental changes in MP caused by high-dose EGCG and oxidation.