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.