Characterization of the Key Odorants in Chinese Zhima Aroma-Type Baijiu by Gas Chromatography–Olfactometry, Quantitative Measurements, Aroma Recombination, and Omission Studies

Zhima aroma-type Baijiu with typical sesame aroma is particularly popular in northern China. To our knowledge, it is still uncertain which components are important to make contributions to its unique aroma, although a few pieces of research have reported many volatile compounds in this Baijiu. The aroma-active compounds from the Baijiu were researched in this paper. A total of 56 odorants were identified in Chinese Zhima aroma-type Baijiu by aroma extract dilution analysis (AEDA). Their odor activity values (OAVs) were determined by different quantitative measurements, and then 26 aroma compounds were further confirmed as important odorants due to their OAVs ≥ 1, and these had higher values, such as ethyl hexanoate (OAV 2691), 3-methylbutanal (2403), ethyl pentanoate (1019), and so on. The overall aroma of Zhima aroma-type Baijiu could be simulated by mixing of the 26 key odorants in their measured concentrations. The similarity of the overall aroma profiles between the recombination model and the commercial sample was judged to be 2.7 out of 3.0 points. Omission experiments further corroborated the importance of methional and ethyl hexanoate for the overall aroma of Chinese Zhima aroma-type Baijiu.