浓香型白酒窖内不同空间位置原酒风味物质初步分析

Preliminary analysis on flavor substances of fermented grains in different layers of strong-flavor Baijiu

为探究浓香型白酒窖池内不同空间位置发酵原酒之间的风味物质差异,运用理化检测及气相色谱-质谱联用技术(GC-MS)对不同空间位置原酒进行测定,结合多元统计分析对数据进行聚类分析(CA)、主成分分析(PCA)、正交偏最小二乘判别分析(OPLS-DA)。结果表明,原酒的总酸、总酯含量随着窖池深度增加而显著增加(P<0.05)。原酒中共检测出42种风味物质,各类风味物质含量随窖池深度而增加。CA与PCA结果显示,上层原酒与中、下层原酒风味物质种类以及数量较为一致,但含量方面存在明显差异。OPLS-DA与维恩分析结果显示,不同空间位置原酒中共得到28种具有代表性的差异风味物质,其中己酸乙酯、戊酸乙酯、正己醇、正丁醇、丁酸、乙酸为上、中、下层原酒共有的6种差异风味物质,且含量随着窖池深度递增,而3-甲基丁醇则呈相反趋势。综上,利用挥发性风味成分的差异结合多元统计分析方法,可以解析不同空间位置原酒差异风味物质,以及为提高原酒质量提供一定参考。

In order to explore the difference of flavor substances between the original liquor of different spatial locations of strong-flavor(Nongxiangxing)Baijiu pits,the original liquor in different spatial locations were detected by physicochemical detection and GC-MS.The results were analyzed combined with multivariate statistical analysis,cluster analysis(CA),principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA).The results showed that the total acid and total ester content of the original liquor significantly increased with the increase of pit depth(P<0.05).A total of 42 flavor substances were detected in the original liquor,and the contents of various categories flavor compounds increased with the depth of the pit.CA and PCA results showed that the types and quantities of flavor substances in the upper layer of the original liquor were relatively consistent with those in the middle and lower layers of the original liquor,but there were significant differences in content.OPLS-DA and Venn analysis results showed that 28 representative difference flavor compounds were obtained from different spatial locations of the original liquor,among which ethyl hexanoate,ethyl pentanoate,n-hexanol,n-butanol,butyric acid and acetic acid were the common 6 kind of difference flavor compounds of the upper,middle and lower layers of the original liquor,and the content increased with the depth of the pit,while 3-methylbutanol showed the opposite trend.In summary,the difference of volatile flavor components combined with multivariate statistical analysis method could be used to analyze the difference flavor substances of original liquor in different spatial locations,and provide some reference for improving the quality of original liquor.