Effects Of Key Flavor Compounds In The Rice-flavored Baijiu On The Alcohol Metabolism And The Contribution Of Brew Microorganisms In Jiuqu

In this study,GC-MS and ICS-3000 ion chromatography were used to analyze the skeleton flavor compounds in the four commercially available rice-flavored baijiu,and the contribution of each skeleton component to the main components of each category was analyzed by combining the principal components.Fine behavioral analysis and expression level analysis of alcohol metabolism biomarkers were used to determine the main flavor components affecting the metabolism of Mixiang liquor after drinking.Finally,high-throughput sequencing technology and microbial isolation and functional research methods were used to explore the microbial community structure ofrice-flavored baijiu.And its main contribution to the main flavor components in the fermentation process of the microorganisms and their effects,provide a research basis for improving the quality of rice-flavored liquor based on microbial improvement of koji and improving the level of post-drinking metabolism.The results of the study are as follows:(1)The main aroma components and characteristic aroma components of the main products of rice-flavored baijiu were analyzed by GC-MS and ion chromatography,and then the trace components that played a major role in the four commercially available rice-flavored baijiu were quantitatively determined and analyzed by PCA analysis.The skeleton components affecting rice-flavored baijiu have a greater contribution to the main components of their respective categories.The results found that: isobutanol,isoamyl alcohol,methanol,isovaleraldehyde,furfural,acetaldehyde,valeric acid,n-butyric acid,ethyl formate,ethyl hexanoate and other trace alcohol components in the main components of their respective categories.It is speculated that these components have a certain relationship with the metabolism of rice-flavored baijiu after drinking.(2)The key substances affecting the metabolism of rice-flavored baijiu after drinking were determined through the behavioral research experiments of mice and the comparative analysis of the metabolism and accumulation of ethanol and acetaldehyde in the blood after drinking.It was found that after gavage with different concentrations of different flavor components,isobutanol,isoamyl alcohol,acetaldehyde,caproic acid group and ethyl acetate had significant inhibitory effects on the motor behavior of animals after gavage(P<0.05),which promoted the negative effect of alcohol.The metabolism of alcohol in the blood was reduced,and the negative effects of isobutanol and isoamyl alcohol on the metabolism of rice-flavored baijiu after drinking were more significant.It was further confirmed that isobutanol and isoamyl alcohol were the key body components affecting the metabolism of rice-flavored baijiu.(3)Mainly through Illumina high-throughput sequencing technology,the microflora structure of rice-flavored baijiu produced by two different processes provided by the winery was analyzed,and the main functional microorganisms were isolated and purified,and then the fermented flavor products were analyzed and studied.Contribution of yeast microorganisms to the formation of key flavors in rice-flavored baijiu.The study found that the genus level structure of traditional koji-making microorganisms was more abundant than that of disc koji-making,but it was impossible to determine which genus of microorganisms was significantly related to the production of higher alcohols.After re-screening,separation,purification and identification,as well as flavor analysis of fermentation broth,it was found for the first time that Saccharomyces cerevisiae and Rhizopus oryzae had a great contribution to the production of higher alcohols in rice-flavored baijiu fermentation.