3种高温大曲功能特征与微生物群落结构差异性分析

Differences in Functional Characteristics and Microbial Community Structures of Three Types of High-Temperature Daqu

通过分析3种不同颜色(黑、黄、白)高温大曲理化指标、挥发性风味物质和微生物群落组成等,初步揭示3种大曲的品质差异性。理化指标结果显示黑曲的酸度、水分含量及酒化力较高,白曲的糖化力、发酵力、酯化力最高,黄曲的淀粉含量最高。风味物质分析表明己酸乙酯、乙酸乙酯、苯乙醇、1-己醇、糠醛等风味物质在3种大曲中均存在明显差异。微生物群落结构分析发现,3种大曲中Bacillus、Scopulibacillus为主要优势细菌,Thermomyces、Thermoascus为主要真菌属。冗余分析表明Bacillus、Thermomyces与发酵力、酯化力、糖化力呈正相关。Spearman相关分析表明Scopulibacillus、Virgibacillus、Aspergillus与大多数关键的挥发性风味化合物显示出正相关。本研究系统探索不同颜色高温大曲的理化指标、挥发性风味物质和微生物群落组成等的功能特征与差异,解析高温大曲品质差异根源,为其在酱酒生产中的合理使用提供数据参考,对实现酿酒生产工艺的标准化具有重要价值。

This study investigated the differences in the physicochemical indexes,volatile flavor substances and microbial community composition of three different colored Daqu(black,yellow and white).Physicochemical analyses showed that the acidity,moisture content and saccharifying power of black Daqu were intermediate between those of yellow and white Daqu,white Daqu had the highest saccharifying power,fermenting power,and esterifying power,and yellow Daqu contained the highest starch content.Flavor substance analysis indicated significant differences in the contents of ethyl caproate,ethyl acetate,phenylethyl alcohol,1-hexanol and furfural among the three types of Daqu.Microbial community structure analysis revealed that Bacillus and Scopulibacillus were the dominant bacteria,and Thermomyces and Thermoascus were the major fungi in all three types of Daqu.Redundancy analysis(RDA)suggested that Bacillus and Thermomyces had a positive correlation with fermenting power,esterifying power and saccharifying power.Spearman correlation analysis showed that Scopulibacillus,Virgibacillus and Aspergillus were positively correlated with most key flavor compounds.This study provides reference data for the rational application of Daqu in the production of Jiang-flavor Baijiu and is of great value for the standardization of Jiang-flavor Baijiu production.