L -半胱氨酸与发酵酸浆协同作用优化玉米湿磨工艺

为了改进玉米湿磨工艺，采用L-半胱氨酸替代传统浸泡工艺中的SO2，降低传统玉米淀粉生产过程中由SO2浸泡引起的环境污染。在具有絮凝活性的副干酪乳杆菌副干酪亚种L1发酵液制成的玉米酸浆中加入L-半胱氨酸，浸泡玉米碎粒，浸泡一定时间后加水磨浆，过筛除去纤维等杂质，淀粉在具有絮凝活性的副干酪乳杆菌副干酪亚种L1的作用下迅速沉降。通过改变酸浆的用量、L-半胱氨酸用量、浸泡温度、浸泡pH值、浸泡时间和菌种接入量，考察各因素对浸泡液中可溶性蛋白质的增量和淀粉提取率的影响，并采用响应面法确定最佳湿磨工艺。结果表明：最佳工艺参数为浸泡时间48 h、L-半胱氨酸质量浓度1.5 g/100 mL、浸泡pH 7、自然发酵酸浆用量比（m（玉米粒质量）∶V（酸浆体积））1∶4、浸泡温度30 ℃，此条件下淀粉提取率的最大值为93.21%。

Optimization of Corn Wet-Milling by Synergistic Action of L-Cysteine and Fermented Corn Juice

In order to improve corn wet-milling, L-cysteine was used to replace SO2 in traditional steeping process for
reducing the pollution of SO2. L-Cysteine was added to a sour liquid, corn juice fermented by Lactobacillus paracasei
subsp. paracasei L1. Crushed corn samples were steeped in the steeping liquid and milled with water after a certain time
of steeping and sieved to remove impurities such as fiber. Starch was sedimented quickly under the action of Lactobacillus
paracasei subsp. paracasei L1 which has high flocculating activity. The effects of various factors on the increment of
soluble protein in steeping liquid and starch extraction yield were studied by changing the amounts of fermented corn juice
and L-cysteine, steeping time, steeping temperature, pH and inoculum size. The optimum conditions for corn wet-milling
were determined by response surface methodology as follows: a ratio of solid to liquid (fermented corn juice) of 1:4 (m/V),
an L-cysteine concentration of 1.5 g/100 mL, pH 7, a steeping temperature of 30 ℃, and a steeping duration of 48 h. Under
these conditions, the maximum extraction yield of starch was 93.21%.