Antioxidant peptides from the mixed-distillate of Baijiu fermented grains and soy sauce residue interact with flavor substances in sauce-aroma Baijiu

The antioxidant peptides of Leu-Pro-Phe (LPF), Leu-Tyr-Pro (LYP), Val-Leu-Pro-Phe (VLPF), Val-Gly-Phe-Cys (VGFC), Pro-Leu-Phe (PLF), and Phe-Thr-Phe (FTF) were screened from the mixed-distillate of Baijiu fermented grains and soy sauce residue for verifying the effect on flavor of sauce-aroma Baijiu by gas chromatography (GC), ultraviolet (UV) wavelength scanning, and molecular docking. These peptides preferred to inhibit the volatilization of esters and pyrazines. Among them, FTF had more obvious inhibitory effect on it, responsible for the formed hydrogen bonds with the flavor substance. It presented the strongest binding energy of -3.17 kcal/mol. The flavor substances preferred to form hydrogen bonds with the peptides composed of Leu, Val, Phe, Thr, Pro, or Cys amino acid residues, in which the NH- group was easier to bind with flavor substances than OH- group and CH 3 - group. This study is of great significance for clarifying intramolecular interaction between antioxidant peptides and flavor substances for improving the flavor and health quality of sauce-aroma Baijiu. • The peptides with the highest probability of bioactivity were selected and synthesized. • The interactions between antioxidant-active peptides and flavor substances were analyzed. • These peptides preferred to inhibit the volatility of esters and pyrazines. • These peptides inhibited their volatilization by forming hydrogen bonds with flavor substances. • The peptides composed of Leu, Val, and Phe were more likely to form hydrogen bonds with the flavor substances.