混合菌发酵对豆粕品质的影响

Effects of fermentation by mixed strains on quality of soybean meal

【目的】评价唾液乳杆菌等混合菌发酵对豆粕脲酶、胰蛋白酶抑制因子、黄曲霉毒素B1以及大豆异黄酮苷元含量的影响,为工业发酵处理提供经济实用的豆粕脱毒方法.【方法】以Lactobacillus salivarius REN、Lactobacillus paracasei和Bacillus thuringiensis混合菌发酵豆粕,考察预处理条件、发酵温度与发酵时间对豆粕脲酶活性的影响,并考察最优条件下发酵对豆粕胰蛋白酶抑制因子等毒性物质含量的影响.【结果】最优工艺为豆粕无需未作加热预处理、39℃发酵72h,与未发酵生豆粕相比,发酵后豆粕脲酶活性降低95.4%,胰蛋白酶抑制因子降低77.8%,黄曲霉毒素降低25.2%.以300kg豆粕进行小规模中试生产性发酵试验,.结果表明,豆粕发酵过程稳定,发酵后豆粕脲酶活性降低95%,发酵后豆粕经50℃烘干,产品水分含量为6%,pH值为4.30,产生柔和酸味,产品颜色加深呈浅棕色、粒度未发生改变、产生柔和酸味.【结论】混合菌发酵提高了豆粕品质,优化工艺适合工业化生产.

【Objective】In order to supply a soybean meal detoxification way,mixed strains including Lactobacillus salivarius REN were used to ferment soybean meal to evaluate its effect on the urease acitivity,content of trypsin inhibitor and aflatoxin B1 of fermented product.【Method】Mixed strains of Lactobacillus salivarius REN,Lactobacillus paracasei and Bacillus thuringiensis were used to ferment soybean meal to study the effects of pretreatment condition,fermentation temperature and time on the urease activity and the effect fermentation on poisonous substance such as trypsin inhibitor and aflatoxin B1.【Result】The optimal process was that soybean meal without being preheated was fermented at 39℃for 72 h.Compared with soybean meal without fermentation,the urease activity of soybean meal fermented reduced by95.4%,trypsin inhibitor decreased by 77.8%,and aflatoxin B1 reduced by 25.2%.The productive test was conducted using 300 kg soybean meal,the result showed that the fermentation process was stable,the urease activity decreased by 95%.After drying at 50 ℃,the moisture content of fermentative soybean meal was 5.1%and pH value was 4.30,the sourness was soft,the color became deeper as light brown and parti-cle size unchanged.【Conclusion】The mixed fermentation could improve the quality of soybean meal,and optimal process is suitable for the industrial production.