Identification and Taste Presentation Characteristics of Umami Peptides from Hybrid Pork Duroc × (Gaoligongshan × Saba) Based on Peptidomics, Machine Learning, Molecular Docking, and Molecular Dynamics Simulation

The study identified novel umami peptides from hybrid pork Duroc × (Gaoligongshan × Saba) (DGS) and explored their interaction mechanisms with T1R1/T1R3. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) characterized peptide profiles of DGS hot meat (DGSH) and chilled meat (DGSC), revealing a greater umami peptide potential in DGSC. Seven potential umami peptides were screened via bioinformatics and conformational relationship analysis. Sensory evaluation showed five novel peptides (VEGK, VESL, LEEK, LPEAL, and KRLMEDTED) had umami thresholds of 0.21-0.48 mg/mL. Electronic tongue analysis indicated VESL/LEEK had exceeded the umami intensity of equiconcentration MSG, while VEGK exceeded double-concentration MSG. Molecular docking showed the five novel peptides bound to T1R1/T1R3 mainly via hydrogen bonds, and molecular dynamics confirmed stable binding. This provides a scientific basis for enriching Yunnan local hybrid DGS pork flavor compounds and decoding its palatability.