市售大酱微生物群落检测及总黄酮含量测定

Analysis of Microbiological Compositions of Commercially Available Fermented Soybean Paste

大酱发酵需经过几个阶段,在此期间,会产生霉菌、酵母菌、乳酸菌等不同种类的微生物。同时酱类食品中也可能会有芽孢菌的存在。采购6种市场中出售的大酱作为样品,进行微生物学状况分析。主要通过平板菌落计数法对大酱样品中的霉菌、酵母菌、乳酸菌及芽孢进行了菌落计数,观察菌落形态,并分析菌相构成。同时对大酱样品中总黄酮的含量进行了测定。试验结果显示市售大酱样品中乳酸菌菌落数的数量级平均达到105 cfu/g^107cfu/g;霉菌及酵母菌数量较少,霉菌菌落的数量级普遍为103 cfu/g,酵母菌菌落的数量级最高达到103 cfu/g;而芽孢数量较多,其菌落数的数量级最高达到了105 cfu/g。将霉菌及酵母菌的数量同自然发酵的农家大酱相比,可以看出市售大酱中霉菌和酵母菌的含量有所下降。因此推测菌相构成可能有所变化。通过分光光度法测定总黄酮含量,结果表明大酱中总黄酮含量较少,6种样品中总黄酮含量最高仅达到1.26 mg/g。

There＇re different types of microorganisms will be produced in the several stages of soybean paste fermentation. Mainly includes lactic acid bacteria, yeasts, molds, etc. At the same time, the Bacillus may also in the soybean paste. 6 samples of soybean paste collected from market were investigated in this paper. Some microbiological compositions were determined, including total counts of lactic acid bacteria, molds, yeasts and Bacillus. While the total flavonoids contents of the soybean paste samples were determined. The result showed that the total counts of lactic acid bacteria in the soybean paste samples were average 105 cfu/ g-107 cfu/g, but the total counts of molds and yeasts in part of the samples were just 103 cfu/g. And the total counts of Bacillus in the soybean paste samples were over 105 cfu/g. Compared with nature fermented soybean paste, the counts of molds and yeasts were decline. The result indicated that the microbiological compositions of the soybean paste samples maybe changed. There were less total flavonoids contents in the soybean paste, only up to 1.26 mg/g.