Identification of Oligopeptides in the Distillates from Various Rounds of Soy Sauce-Flavored Baijiu and Their Effect on the Ester-Acid-Alcohol Profile in Baijiu.

Endogenous peptides in Baijiu have primarily focused on finished liquor research, with limited attention given to the peptides in base liquor prior to blending. Liquid chromatography-tandem mass spectrometry (LC-MS) was employed to identify endogenous peptides in the distillates from the first to seventh rounds of soy sauce-flavored Baijiu. Two hundred and five oligopeptides were identified from these distillates, all of which had molecular weights below 1000 Da and were composed of amino acid residues associated with flavor (sweet, sour, and bitter) and biological activity.

Identification and Free Radical Scavenging Activity of Oligopeptides from Mixed-Distillate Fermented Baijiu Grains and Soy Sauce Residue.

This study aimed to explore the potential antioxidant activity and mechanism of oligopeptides from sauce-aroma Baijiu. The oligopeptides of Val-Leu-Pro-Phe (VLPF), Pro-Leu-Phe (PLF), Val-Gly-Phe-Cys (VGFC), Leu-Tyr-Pro (LYP), Leu-Pro-Phe (LPF), and Phe-Thr-Phe (FTF) were identified by liquid chromatography-mass spectrometry (LC-MS) from the mixed-distillate of Baijiu fermented grains and soy sauce residue (MDFS). The antioxidant mechanism of these oligopeptides on scavenging DPPH•, ABTS•, and hydroxide radicals was investigated, respectively.