不同等级中高温大曲微生物群落、理化指标及挥发性风味物质差异分析OA

The physicochemical indexes,volatile flavor components and microbial community diversity of different grades of medium-high tempera-ture Daqu(special grade Daqu,excellent grade Daqu and common grade Daqu)were detected by conventional detection methods,GC-MS and high-throughput sequencing technology,respectively,and the correlation among the three was analyzed.The results showed that the physicochemical in-dexes of different Daqu samples were different.The saccharification power(865.10 U),esterification power(617.61 U),fermentation power(0.27 U)and liquefaction power(1.78 U)of special grade Daqu were the highest,the moisture content(9.01％)of excellent grade Daqu was higher,and the acidity(1.06 mmol/10 g)of common grade Daqu was higher.A total of 6 dominant bacterial genera and 5 dominant fungal genera were annotated from Daqu samples.The microbial community structure of different Daqu samples was different.Based on the linear discriminant analysis(LDA)value＞3.5 and P＜0.05,a total of 5 different bacterial genera and 3 different fungal genera were screened.A total of 47 volatile flavor compounds were de-tected from Daqu samples,and there were differences in volatile flavor compounds among different Daqu samples.A total of 13 key differential volatile flavor substances were screened based on variable importance in the projection(VIP)value＞1,P＜0.05 and odor activity value(OAV)＞1.The results of correlation analysis showed that the dominant microbial genera had a certain correlation with physicochemical indexes and volatile flavor components of Daqu.