CHEN Fajun, MING Hongmei, ZHENG Jia, WEI Jinping, LUO Zhu, SU Jian, LI Yajun, MA Hao
Three pre-treatment methods, including direct injection, liquid-liquid extraction, and headspace solid-phase microextraction, were used in combination with GC-MS to study multi-grain Nongxiangxing Baijiu in three grades, including Teji, Youji, and Yiji raw liquor. Results showed that there were 107, 99, and 105 compounds, and 90 common compounds, respectively, in the three types of raw liquor. Through orthogonal partial least squares analysis and variance analysis, combined with the odor activity value, 14 key differential compounds were selected from 90 common compounds, including ethyl hexanoate, ethyl octanoate, ethyl valerate, 3-methylbutanoate ethyl ester, ethyl butyrate, butyl hexanoate, valeric acid, butyric acid, hexyl hexanoate, hexanoic acid, isoamyl hexanoate, propyl hexanoate, ethyl heptanoate, and ethyl nonanoate. It was worth noting that five compounds were particularly influential: ethyl hexanoate, ethyl octanoate, ethyl valerate, 3-methylbutanoate ethyl ester, and ethyl butyrate, which could be preliminarily identified as important flavor components contributing to grade differences. Because in each grade of raw liquor, their odor activity values exceed 1 000, and higher odor activity values are displayed in both Teji and Youji raw liquor, while lower values were observed in Yiji raw liquor.
