Screening of novel umami peptides with saltiness enhancement effect using molecular docking and structure-activity analysis.

In this study, to explore a healthier and safer alternative method for reducing salt intake, new umami peptides were identified from the hydrolysate of Ruditapes philippinarum through structure-activity relationship and molecular docking. The impact of these peptides on enhancing salty taste was examined using a sensory test and an electronic tongue evaluation. The mechanism of salt reduction was investigated through molecular docking. In addition, eight new umami peptides: LEDKVE, DEELNKLK, DLKEKL, LEER, AEKEEEFENT, EQEEYKK, EFDKK, and GEDFDNKLV, extracted from the hydrolysate of Ruditapes philippinarum, were identified, and their taste thresholds ranged from 0.12 to 0.24 mmol/L. When new umami peptides were mixed with 3 g/L of NaCl, the saltiness of NaCl was enhanced. Among the umami peptides studied, LEDKVE had the most significant impact on improving saltiness, achieving a perception of salty taste equivalent to 5 g/L of NaCl in a solution of 3 g/L of NaCl. Molecular docking revealed that the umami peptide interacted with transmembrane channel-like protein 4 (TMC4) through hydrogen bonds, and the key active sites, including Lys568, Trp145, Tyr565, Arg151, and Gln155, potentially played a crucial role in taste perception. This study offers valuable insights into the development of flavorful and nutritious seasonings that can enhance nutritional quality.