Structure-activity relationship and sensory analysis of butyryl-amino acids as potent umami enhancers

Umami taste enhancers play a crucial role in improving the palatability and flavor profile of food products. This study investigated the umami-enhancing properties and structure-activity relationships of butyryl-amino acids using a comprehensive approach combining virtual screening via molecular docking, sensory evaluation, and multivariate analysis. Twenty butyryl-amino acids were initially screened through molecular docking, and the five compounds with the highest binding affinities (butyryl-Gln, butyryl-Arg, butyryl-Tyr, butyryl-Phe, and butyryl-Trp) were selected for further sensory evaluation. Sensory evaluation confirmed their potent umami-enhancing effects, with butyryl-Gln and butyryl-Phe showing the lowest thresholds and the most pronounced effects on umami taste. Multivariate analysis identified key structural features, such as lower molecular weight, shorter side chain length, optimal hydrophobicity, and fewer hydrogen bonding moieties, as important contributors to enhanced umami taste perception. Interaction analysis of the butyryl-amino acids with specific amino acid residues in the umami taste receptor highlighted the crucial roles of Ala302, Gly168, Val187, Ser148, Ser170, Ser276 and Glu148 in modulating various aspects of umami taste. These findings provide valuable insights into the molecular basis and structure-activity relationships of butyryl-amino acids as umami enhancers, guiding the rational design of novel compounds for more palatable food products with particular applications in low-sodium food development.