不同发酵醅层的浓香型原酒风味成分对比分析

Preliminary Study on the Differences in Flavor Components of Nongxiang Crude Liquor from Different Layers of Fermented Grains

为探究窖池内不同发酵醅层原酒风味成分的差异性,应用GC-MS/MS技术分析了不同发酵醅层浓香型原酒的香气成分,共鉴定出54种风味物质,其中,酯类29种、醇类12种、酸类4种、其他类9种。2-己醇、2-庚酮仅在上层酒醅原酒中检测到,1,2-二甲酰氧基丙烷仅在下层酒醅原酒中检测到。结合风味物质半定量分析,发现在不同醅层原酒中酯类物质占比最高,均达到67%以上,且酯类、醇类及酸类物质占比存在一定差异。利用偏最小二乘判别分析(PLS-DA)筛选出33种对不同醅层原酒具有差异贡献的风味物质,并结合OAV值分析,发现庚酸乙酯、己酸己酯、己酸为下层酒醅原酒的关键特征风味物质,苯乙酸乙酯为上层酒醅原酒的关键特征风味物质,己酸乙酯、丁酸乙酯、辛酸乙酯、3-甲基丁酸乙酯、己酸丁酯为不同醅层原酒共有的关键特征风味物质。

In order to explore the differences in the flavor components of the crude liquor from different layers of fermented grains in pit,the flavor components of the crude liquor from different layers of fermented grains was analyzed by GC-MS/MS.A total of 54 flavor substances were identified,including 29 esters,12 alcohols,4 acids and 9 other substances.Among them,2-hexanol and 2-heptanone were only detected in the crude liquor from the upper layer of fermented grains,and 1,2-dimethoxypropane was only detected in the crude liquor from the bottom layer of fermented grains.Combined with the semi-quantitative analysis of flavor substances,it was found that esters accounted for the highest proportion(over 67 %) in the crude liquor from different layers of fermented grains,and there were certain differences in the proportion of esters,alcohols and acids.Using partial least squares-discriminant analysis(PLSDA),33 substances with different contributions to the flavor of the crude liquor were screened out.Combined with OAV value analysis,it was found that ethyl heptanoate,hexyl caproate,and caproic acid were the characteristic flavor substances of the crude liquor from the bottom layer of fermented grains,ethyl phenylacetate was the characteristic flavor substance of the crude liquor from the upper layer of fermented grains,and ethyl caproate,ethyl butyrate,ethyl caprylate,ethyl 3-methylbutyrate,and butyl caproate were the characteristic flavor substances shared by the crude liquor from different layers of fermented grains.