Taste properties and mechanism of umami peptides from Tricholoma mongolum Imai via insight into multisensory techniques, virtual screening, and molecular simulations

Tricholoma mongolum Imai (TMI) is a mushroom native to China, well known for its strong umami taste. Umami-rich TMI hydrolysates were prepared, followed by ultrafiltration. In the subsequent phase, a multi-step in silico screening approach was applied to select four promising umami peptide candidates. Their capacity to enhance umami taste was subsequently assessed through both human sensory panels and electronic tongue analysis. The results of sensory evaluations showed that these four peptides shared a similar qualitative taste profile (umami, sourness, and sweetness) but differed in their detection thresholds, which ranged from 0.07 to 0.13 mmol/L. Among the identified peptides, FDPL, VPDPL, and VDW demonstrated the ability to increase the umami intensity of a 3 mg/mL MSG solution, acting either through a synergistic or an additive mechanism. Molecular docking analyses indicated that hydrogen bonds and hydrophobic interactions played key roles in binding these umami-enhancing peptides to the T1R1 and T1R3 taste receptors. Meanwhile, molecular dynamics simulations confirmed that the receptors and the four peptides formed stable, tight complexes throughout the simulation period. Taken together, these results offer a reliable theoretical foundation for the identification of umami-boosting peptides and the development of innovative umami-enhancing food ingredients sourced from TMI.