Collagen Glycopeptides from Transglutaminase-Induced Glycosylation Exhibit a Significant Salt Taste-Enhancing Effect

This study aimed to prepare collagen glycopeptides by transglutaminase-induced glycosylation and to explore their salt taste-enhancing effects and mechanism. Collagen glycopeptides were obtained by Flavourzyme-catalyzed hydrolysis, followed by transglutaminase-induced glycosylation. The salt taste-enhancing effects of collagen glycopeptides were evaluated by sensory evaluation and an electronic tongue. LC-MS/MS and molecular docking technologies were employed to investigate the underlying mechanism responsible for the salt taste-enhancing effect. The optimal conditions were 5 h for enzymatic hydrolysis, 3 h for enzymatic glycosylation, and 1.0% (E/S, w/w) for transglutaminase. The grafting degree of collagen glycopeptides was 26.9 mg/g, and the salt taste-enhancing rate was 59.0%. LC-MS/MS analysis revealed that Gln was the glycosylation modification site. Molecular docking confirmed that collagen glycopeptides can bind to salt taste receptors epithelial sodium channel protein and transient receptor potential vanilloid 1 through hydrogen bonds and hydrophobic interaction. Overall, collagen glycopeptides have a significant salt taste-enhancing effect, which contributes to the application of collagen glycopeptides for salt reduction without compromising taste in the food industry.