麦麸阿魏酸糖酯微生物发酵工艺优化及体外抗氧化和益生活性评价

以麦麸为原料，对固态发酵制备麦麸阿魏酸糖酯（Feruloylated glycosides，FGs）的工艺进行优化，并对其体外抗氧化及益生活性进行评价。以植物乳杆菌、枯草芽孢杆菌、地衣芽孢杆菌、酿酒酵母为发酵菌种，采取单菌发酵和混菌发酵筛选最优菌种组合，考察接种量、发酵温度、发酵时间、料水比对麦麸FGs产量的影响，通过响应面试验设计优化发酵工艺。结果表明:以枯草芽孢杆菌:地衣芽孢杆菌:酿酒酵母=1:1:1发酵麦麸时，FGs产量最高；最佳固态发酵工艺条件为发酵温度42.5℃，发酵时间58.5 h，接种量10.7%，料水比1:1.16（g/mL），在此条件下FGs产量为1273.18 nmol/g；抗氧化实验结果表明，DPPH自由基清除率高达87.42%（1 mg/mL），羟基自由基清除率为33.68%（4 mg/mL），还原力为1.078（4 mg/mL）。发酵麦麸FGs可有效促进嗜热链球菌和植物乳杆菌的增殖。综上所述，以枯草芽孢杆菌、地衣芽孢杆菌和酿酒酵母混菌发酵制备的麦麸FGs有一定的抗氧化和益生活性。

Optimization of Fermentation Process for Feruloylated Glycosides from Wheat Bran and Evaluation of Its Antioxidant and Probiotic Activities in Vitro

The fermentation process for feruloylated glycosides(FGs)from wheat bran was optimized.The in vitro probiotic and antioxidant activities of the extracted FGs from fermented wheat bran were analyzed.Lactobacillus plantarum CGMCC 1.2437,Bacillus subtilis CGMCC 1.0892,Bacillus licheniformis CGMCC 1.813,Saccharomyces cerevisiae CGMCC 2.119 were used as starter strains.The suitable starter strains were screened by different single starter strain and starter strains combination.The effects of level of inoculum,incubation temperature,incubation duration,material to water ratio on the FGs yield were investigated.The fermentation conditions were further optimized using response surface methodology.The results showed that FGs yield was highest when the combination of B.subtilis,B.licheniformis and S cerevisiae were as starter strain.The optimum fermentation conditions were level of incubation temperature 42.5℃,incubation duration 58.5 h,inoculum 10.7%,material to water ratio 1∶1.16(g/mL).Under this optimum fermentation condition,the FGs yield was 1273.18 nmol/g.The extracted FGs from fermented wheat bran had strong DPPH radicals scavenging capacity(87.42%,1 mg/mL),hydroxyl radicals scavenging capacity(33.68%,4 mg/mL)and reducing power(1.078,4 mg/mL).The extracted FGs from fermented wheat bran promoted the proliferation of Streptococcus thermophiles and Lactobacillus plantarum.In conclusion,the FGs from wheat bran fermented by B.subtilis,B.licheniformis and S cerevisiae could exert antioxidant and prebiotic activity.