混菌固态发酵花生粕的工艺优化

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。

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

The peanut meal was fermented in a solid state by a mixture of Bacillus natto and Monascus. The activity of nattokinase and the content of γ-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 of γ-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.