Identification of Key Aging-Related Aroma Compounds in Sesame-Flavor Baijiu via Chemometrics and Molecular Docking: Insights into Flavor Formation Mechanisms

Abstract

On the basis of 12 sesame-flavor Baijiu spanning multiple vintages, this study systematically revealed aging patterns through chemometrics, sensory, physicochemical, and molecular docking analyses. Sensory profiling showed that aging enhanced sesame and aged aromas while weakening fruity and alcoholic notes. Physically, prolonged aging increased the particle size, regularized the morphology, and intensified yellowing. Gas chromatography–olfactometry–mass spectrometry and omission tests confirmed 21 key aroma contributors to aging traits. Molecular docking demonstrated their strong binding to olfactory receptors, with longifolene exhibiting the highest affinity, suggesting that receptor binding enhances perceived aging characteristics. Crucially, statistical change-point analysis identified the third year of aging as the volatile kinetic transition point, while multidimensional sensory, physical, and chemical cross-validation highlighted 5 years as a key empirical maturation reference. The subsequent 5–12-year period constitutes a continuous maturation phase, where sensory complexity dynamically evolves. These findings elucidate flavor evolution mechanisms, offering practical guidance for optimizing production planning, minimizing overaging losses, and authenticating aged sesame-flavor Baijiu.