Abstract:This study explored the molecular interaction mechanism and synergistic antioxidant effects between the peptide and anthocyanin. The fluorescence quenching method and three in vitro antioxidant evaluation systems，including 1，1-diphenyl-2-picrylhydrazyl （DPPH），2，2'-azinobis（3-ethylbenzothiazoline-6-sulfonic acid）（ABTS），and ferric reducing antioxidant power （FRAP） assays，were adopted. Combined with the Chou-Talalay combination index （CI） and synergistic effect coefficient （SE），the molecular interaction characteristics and in vitro synergistic antioxidant effects of Val-Pro-Trp （VPW） and cyanidin-3-O-glucoside（C3G） were systematically investigated. The results showed that C3G significantly quenched the fluorescence of VPW in a dose-dependent manner. Under neutral conditions，the calculated Gibbs free energy （ΔG） was-27.28 kJ/mol，which indicated that VPW and C3G had potential intermolecular interactions and spontaneously formed VPW-C3G complexes with a single binding site through hydrophobic interaction. When the mass concentration ratio of VPW to C3G was 1∶1，significant synergistic antioxidant effects were observed in DPPH，ABTS and FRAP evaluation models. The combination indices for DPPH and ABTS+radical scavenging activities were0.82and0.86，respectively，while synergistic effect coefficient from the FRAP assay was 0.05.