沉香型白酒酒醅理化特性及细菌群落结构研究

通过高通量测序技术分析了沉香型出池酒醅的细菌群落结构，并对其理化指标和挥发性风味成分进行分析。结果表明，理化指标方面，上层酒醅的淀粉含量显著高于下层酒醅（P＜0.05），但其还原糖含量、酸度和酒精含量均显著低于下层酒醅（P＜0.05）；挥发性风味成分方面，沉香型酒醅中酯类物质是其优势风味产物，分别占上、下层酒醅风味含量的94.8%和86.8%，其中丁酸乙酯、己酸乙酯、乳酸乙酯、己酸、丁酸等典型风味物质在下层酒醅中的含量均明显高于上层酒醅；细菌多样性方面，沉香型上层酒醅中的优势细菌为乳酸杆菌属（Lactobacillus）和醋酸杆菌属（Acetobacter），而下层酒醅中则以乳酸杆菌属为其唯一的优势菌；通过比较发现，上层酒醅中细菌的多样性较下层酒醅更为丰富。

Physicochemical characteristics and bacterial community structure of fermented grains of Chen-flavor Baijiu

The bacterial community structure of pit-unloading fermented grains (Jiupei) of Chen-flavor Baijiu (Chinese liquor) was analyzed by high- throughput sequencing, and the physicochemical indexes and volatile flavor components were detected. The results showed that the starch content of upper fermented grains was significantly higher than lower fermented grains in terms of physicochemical indexes (P＜0.05), but the reducing sugar content, acidity and alcohol content were significantly lower than lower fermented grains (P＜0.05). In terms of volatile flavor components, esters were the dominant flavor products in Chen-flavor fermented grains, accounting for 94.8% and 86.8% of the upper and lower flavor components contents of fermented grains, respectively. The contents of typical flavor substances such as ethyl butyrate, ethyl caproate, ethyl lactate, hexanoic acid and butyric acid in lower fermented grains were higher than upper fermented grains. In terms of bacterial diversity, the dominant bacteria were Lactobacillus and Acetobacter in upper Chen-flavor fermented grains, but the only dominant bacteria were Lactobacillus in the lower fermented grains. By comparison, the bacterial diversity of upper fermented grains was more abundant than lower fermented grains.