Molecular Sensory and GC-MS/MS Profiling of Key Aroma Compounds in Sauce-Flavor Base Baijiu

This study systematically investigated the key aroma compounds across seven consecutive production rounds of Sauce-flavor base baijiu from the Tianfu region using an integrated molecular sensory approach. GC-MS profiling tentatively identified 232 volatile compounds by NIST library matching, while 58 low-content and 12 high-content aroma compounds were quantitatively determined by GC-MS/MS and GC-FID, respectively. Thirty-seven compounds showed literature-based OAV values ≥ 1 and were selected as candidate aroma-active compounds for further sensory evaluation. Aroma recombination and omission experiments provided further sensory evidence for the relevance of 13 aroma compounds, including ethyl furfuryl ether, 1-propanol, ethyl isovalerate, and acetoin, to the aroma profiles of representative production rounds. Quantitative analysis revealed marked round-dependent variations in higher alcohols, esters, and acids, highlighting dynamic changes in the volatile composition of Sauce-flavor base baijiu across successive production rounds. This work provides a quantitative and sensory basis for understanding aroma variation across production rounds within the investigated Sauce-flavor baijiu production system and may provide a reference for subsequent flavor evaluation and process optimization.