Characterization of Key Aroma Compounds in Aged Qingxiangxing Baijiu by Comparative Aroma Extract Dilution Analysis, Quantitative Measurements, Aroma Recombination, and Omission Studies

An understanding of the aroma compounds in liquor can provide insights into aging mechanisms. In this study, the aroma compounds in Qingxiangxing (QXX) baijiu (Chinese liquor) were investigated via the comparative sensory and chemical evaluation of samples stored for 0 years (young) and 45 years (aged). Comparative aroma extract dilution analysis revealed 59 odorants (flavor dilution ≥ 4). Based on further quantification and odor activity value (OAV) calculations, young and aged QXX baijiu had 37 and 41 compounds, respectively, with OAVs ≥ 1. One-way analysis of variance showed significant differences between young and aged QXX baijiu for 26 compounds. Analysis of the variation patterns of these compounds in QXX baijiu aged for different times revealed a significant positive correlation with aging time for 12 compounds. The developed aroma simulation model confirmed sotolon, methional, vanillin, dimethyl trisulfide, benzaldehyde, and 3-hydroxy-2-butanone as key compounds responsible for aged aroma in the QXX baijiu.