Integrating molecular simulation and sensory analysis reveals the sweetness-enhancing mechanism of sweet-aroma compounds in Baijiu.

Sweet perception is crucial for Baijiu's flavor balance and is influenced by endogenous sweet compounds and volatile aromas. Ten representative sweet-aroma compounds and glycerol were investigated to elucidate the sweetness-enhancing mechanism through molecular simulations and sensory evaluation. Molecular docking revealed that all compounds bound stably to T1R2/T1R3 and T1R2/T1R3-glycerol (binding energy < -3.5 kcal/mol) via hydrogen bonds and hydrophobic interactions, primarily acting as "sweetness enhancers" by stabilizing the T1R2/T1R3-glycerol complex. Phenethyl alcohol showed the strongest binding affinity (-5.8 kcal/mol to T1R2, -6.1 kcal/mol to T1R2-glycerol). Molecular dynamics simulations confirmed it formed stable binary and ternary complexes in ethanol-water (1:1, v/v). Sensory and electronic tongue analyses validated that all compounds enhanced 20 mg/L glycerol sweetness, with odor-induced sweetness enhancement (OISE) of 0.73-2.78 and 0.08-3.32, respectively. No sweetness synergistic effects were observed, validating their role as "sweetness enhancers." This study provides a mechanistic basis for Baijiu's sweetness optimization.