Identification of novel umami peptides from truffle and their effects on umami perception when used in combination with MSG or IMP

While much research has focused on volatile compounds in truffle, little attention has been given to its umami, an important flavor component. Here, novel umami peptides derived from truffle were screened, and their taste mechanisms were investigated using virtual screening, molecular docking, and molecular dynamics simulations. Sensory evaluation and electronic tongue experiments were performed to assess their taste characteristics. Additionally, molecular docking simulations were carried out to examine umami perception when selected umami peptides were combined with monosodium glutamate (MSG) or inosine monophosphate (IMP). Eleven peptides were identified as potential umami enhancers in truffles. Among these peptides, DPTEGLRSP exhibited the lowest binding energy (-9.9 kcal/mol) toward the T1R1/T1R3 umami receptor, whereas VDAY showed the highest (-6.7 kcal/mol). Both peptides were found to stably bind to the receptor during molecular dynamics simulations. The umami threshold of DPTEGLRSP was assessed to be lower (0.230 mmol/L). Furthermore, stronger umami perception was observed when IMP was combined with DPTEGLRSP and when MSG was paired with VDAY, indicating distinct synergistic patterns for different peptide-enhancer combinations.