混菌固态发酵花生粕的工艺优化

Optimization of Solid-state Fermentation of Peanut Meal by Mixed Bacteria

采用纳豆芽孢杆菌和红曲霉混合菌株固态发酵花生粕,以纳豆激酶的活力和γ-氨基丁酸的含量为指标,通过单因素实验和正交试验对发酵的温度、时间、料水比、菌种比例、接种量进行优化,确定最佳工艺参数为:温度31℃,发酵时间46 h,料水比为1∶0.4 g/mL,菌种比例(纳豆芽孢杆菌∶红曲霉)2∶1,接种量6%,在此条件下测定纳豆激酶的活力为(844.56±13.80)U/g,γ-氨基丁酸含量为(105.25±0.25)mg/g,对羟自由基清除率为68.46%±0.16%,对DPPH·清除率为76.98%±0.95%,铁还原力的OD值为0.481。

The peanut meal was fermented in a solid state by a mixture of Bacillus natto and Monascus.The activity of nattokinase and the content ofγ-aminobutyric acid were used as indicators.Through single factor experiment and orthogonal experiment,the fermentation temperature,time,feed-water ratio,strain proportion and inoculation amount were optimized.The optimum process parameters were determined as follows:Temperature 31℃,fermentation time 46 h,the ratio of material to water was 1∶0.4 g/mL,the proportion of strains(Bacillus natto∶Monascus)2∶1,inoculation 6%.Under these conditions,the activity of nattokinase was(844.56±13.80)U/g,the content ofγ-aminobutyric acid was(105.25±0.25)mg/g,The hydroxyl radical scavenging rate was 68.46%±0.16%,the DPPH·clearance rate was 76.98%±0.95%,and the OD value of iron reducing power was 0.481.