Sweet Aroma Synergistic Enhancement Mechanism of β-Damascenone in Dry Red Wine

Threshold, S-curve, σ-τ plot, molecular docking, and molecular dynamics simulation (MDS) were used to decode the sweet aroma synergistic enhancement mechanism between β-damascenone and key odorants in dry red wine and olfactory receptors (OR52D1, OR1A1). Synergistic/additive effects predominated in binary/ternary complexes. Particularly, experimental-to-theoretical threshold ratios for β-damascenone with 2,3-butanediol/2,3-butanedione were 0.103 and 0.085, indicating the strongest synergistic effects, with β-damascenone dominating the aroma. Molecular docking and MDS revealed that β-damascenone occupied the primary hydrophobic pocket of olfactory receptors with the lowest binding energies (-60.269, -46.160 kcal/mol) through hydrophobic interactions and van der Waals forces. 2,3-Butanediol/2,3-butanedione alone bound weakly, but in ternary systems they stably bound to secondary hydrophobic sites. MM/GBSA calculations confirmed that ternary systems had lower binding energies than individual ligands, with van der Waals and hydrophobic contributions exceeding the individual contributions, revealing that these forces drive the synergistic binding between weakly binding odorants and β-damascenone, enhancing sweet aroma perception.