微生物复合发酵对豆粕营养品质的影响

Effect of microbial compound fermentation on nutritional quality of soybean meal

从4种具有优良发酵豆粕能力的微生物(枯草芽孢杆菌、酿酒酵母、米根霉、产黄青霉)中筛选最优发酵菌株组合,以粗蛋白含量和大豆肽含量为评价标准,对发酵工艺条件进行优化,并对豆粕固态发酵前后的营养物质含量和抗营养因子变化进行分析。结果显示:枯草芽孢杆菌B-8和米根霉M-1为最优发酵菌株组合。复合发酵最佳发酵工艺条件为:枯草芽孢杆菌和米根霉同时接入到豆粕中,两菌株接种比例2∶1,发酵总接种量10%,发酵温度40℃,料水比1.0∶1.4(质量比),发酵时间96 h。豆粕经复合发酵后,发酵产物中大豆肽、粗蛋白、粗灰分、粗脂肪含量较发酵前均得到显著提升,水分含量显著下降,大分子蛋白质基本降解为10 ku以下的小分子,大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子含量显著低于未发酵豆粕。结果表明,豆粕经复合发酵后营养成分显著增加,抗营养因子含量显著降低,营养品质得到改善。

In this study,the optimum fermentation strain was selected from four strains with excellent ability of fermenting soybean meal(Bacillus subtilis,Saccharomyces cerevisiae,Rhizopus oryzae,Penicillium chrysogenum),and crude protein content and soybean peptide content were taken as evaluation criteria to optimize the fermentation process conditions.The nutrient content and the changes of anti-nutrition factors were analyzed before and after solid-state fermentation of soybean meal.The results showed that B.subtilis B-8 and R.oryzae M-1 were the optimal combination of fermented strains.The optimum fermentation process conditions of compound fermentation were:B.subtilis and R.oryzae were simultaneously introduced into soybean meal,the inoculation ratio of two strains was 2∶1,the total inoculum of fermentation was 10%,the fermentation temperature was 40℃,the ratio of feed to water was 1.0∶1.4,and the fermentation time was 96 hours.After compound fermentation of soybean meal,the content of soybean peptide,crude protein,crude ash and crude fat in the fermentation product was significantly higher than that before fermentation(P<0.05),the moisture content decreased significantly(P<0.05),the macromolecular protein was basically degraded below 10 ku,and glycinin,β-conglycinin and trypsin inhibitor was significantly lower than that of unfermented soybean meal(P<0.05).The above results indicated that the nutrient composition of soybean meal increased significantly and the anti-nutritional factors decreased significantly after the compound fermentation,which means that the nutritional quality of soybean meal was improved a lot.