逆流浸泡玉米浆中微生物的变化及其作用研究

Study on the Distribution and Effect of Microorganism During Countercurrent Steeping of Corn

逆流浸泡工艺已被广泛应用于玉米湿法淀粉生产中。玉米逆流浸泡中微生物会不断生长、繁殖,代谢并产生活性物质作用于玉米籽粒,提高浸泡效果。但目前对玉米浸泡过程中微生物的变化规律及其作用研究不多。采集了中粮生化龙江工厂中两批6个不同时间段的玉米浸泡液(2、10、18、26、33和41 h)共12个样品,测定其有机酸组成、pH和细菌群落结构变化,浸泡液中的有机酸含量和pH都随着浸泡时间逐渐降低,乳酸含量从30 g/L左右(2 h)降低到<10 g/L(41 h),pH维持在4.0±0.2。整个浸泡过程中,乳酸杆菌属占绝对优势并在浸泡前期发酵产生大量乳酸,从2到41 h占比分别为95.8%,89.6%,76.1%,77.9%,52.2%和58.4%。芽孢杆菌属丰度从浸泡10 h开始上升并成为第二优势菌。

The countercurrent steeping of corn has been widely used in the production of starch.During the corn soaking,lactic acid bacteria fermentation broth was added to increase the soaking effect of corn and reduce the use of sulphur.In this paper,12 samples of 6 batches of corn soaking liquid(2,10,18,26,33 and 41 h)were collected from COFCO biochemical Longjiang factory.The organic acid composition,pH and bacterial composition were determined.Both the concentration of organic acid and the pH gradually decreased with time.The lactic acid concentration decreased from about 30 g/L(2 h)to<10 g/L(41 h),and the pH maintained at 4.0±0.2.During the whole soaking process,Lactobacillus was dominant,accounting for 95.8%,89.6%,76.1%,77.9%,52.2%and 58.4%,respectively,from 2 h to 41 h.The abundance of Bacillus increased from 10 h as the second dominant bacteria.