Yeast protein-derived γ-glutamyl peptides prepared by transpeptidation reaction exhibit a pronounced taste-enhancing effect

Abstract

A high-salt diet can induce hypertension, so salt reduction can prevent hypertension. γ-Glutamyl peptides (GGPs) have obvious taste-enhancing effects, while their contents in natural foods are relatively low. Yeast protein rich in Glu/Gln is a good precursor for the preparation of GGPs. In this study, yeast protein-derived GGPs were prepared through hydrolysis and transpeptidation reactions, followed by sensory evaluation and E-tongue analysis. Peptide sequences were identified by LC−MS/MS and screened for molecular docking. The optimal reaction conditions were hydrolysis for 4 h, enzyme concentration of 16 U/g, and transpeptidation for 4 h. GGPs could increase salt and umami intensity by 60.78% and 40.93% based on sensory evaluation, 22.52%, and 16.40% according to E-tongue analysis. Fifteen γ-glutamyl peptides with different peptide lengths were selected for molecular docking. Molecular docking confirmed their binding to calcium-sensing receptors (CaSr) through hydrogen bonds and hydrophobic interaction, while interaction between CaSR receptor and γ-glutamyl di-, tri-, and oligo-peptides varied in binding energy. The stimulation received by CaSR lasted a longer time and varied in intensity. It was further proved that the flavor of mixed peptides has a layered sense and can give people a rich taste experience. Overall, yeast protein-derived GGPs can enhance salt and umami taste, which can reduce salt usage without compromising taste.