凉州熏醋传统酿造过程中代谢产物动态变化分析

通过对凉州熏醋传统酿造过程中代谢产物的动态变化进行分析研究。以工厂化生产现场构建实验技术体系，跟踪测定完成蒸料工段后进入糖化发酵阶段的第1、3、5、8、12、17天的原位料醅中9项与酿醋物料微生物代谢有关的主要理化指标，分析讨论各指标的变化规律及其相互关系，并对测定结果进行Q型聚类分析。随着酿造过程进行，料醅温度、还原糖和酒精质量分数呈先上升后降低趋势，淀粉和蛋白质呈下降趋势，酸度和氨基酸含量呈递增趋势，而水分含量在整个酿造阶段基本保持不变。根据聚类分析结果将整个酿造阶段分为两个阶段，即发酵的第1、3、5天和第8、12、17天。聚类分析结果与凉州熏醋整个酿造工艺的糖化酒化双边发酵和醋酸发酵两个阶段相吻合，表现为在工艺操作层面和代谢产物层面的一致性和延滞性。

Metabolite Dynamics during Traditional Brewing of Liangzhou Fumigated Vinegar

In order to explore the relationship between metabolites and the quality of fumigated vinegar, the metabolite dynamics during the traditional brewing process of Liangzhou fumigated vinegar were studied. In situ samples of fermented grains at the end of 1st, 3rd, 5th, 8th, 12th and 17th of fermentation from a certain production line were determined for their 9 major physicochemical properties related to the microbial metabolism. The changes in the physicochemical properties and the mutual relationships among them were explored. Meanwhile, hierarchical cluster analysis was employed to divide the brewing process. During the brewing process, the temperature and the contents of reducing sugar and alcohol in fermented grains increased at the beginning and then stepped down. The contents of starch and protein decreased till the end of the brewing process. The acidity and amino acid content increased during the whole process, but the moisture content basically did not change throughout the fermentation process. The brewing process was divided into two stages, with the first stage including days 1, 3 and 5, while the second stage days 8, 12 and 17. The result of hierarchical cluster analysis accorded with the actual composition of the brewing process. Consistency and delay were showed between the technological and metabolic levels.