Improvement of active peptide yield, antioxidant activity and anti-aging capacity of rapeseed meal fermented with YY-112 pure fermentation and co-fermentation

A study was carried out to increase the active peptide yield by fermenting with screened Bacillus subtilis YY-112, and investigate the nutrient compositions, antioxidant activity and anti-aging capacity in vitro between screened Bacillus subtilis YY-112 fermentation and co-fermentation with S.cerevisiae YY-21. The objective was to establish a novel method to obtain more active peptides to be used as functional food ingredients to resist aging, and investigate the best way for the rapeseed meal fermentation (pure fermentation and co-fementation). The B. subtilis YY-11 was screened and bred as B. subtilis YY-112 by the mutagenesis. The peptide concentration of the RSM fermented extruded RSM (FERSM) with B. subtilis YY-112 increased up to 231.75 mg/g (P < 0.001), and the specific surface area of the FERSM with pure B. subtilis YY-112 fermentation was significantly larger than that of the co-FERSM with S.cerevisiae YY-21 (P < 0.05). The ratio of the molecular weight (<5Da) of the FERSM with pure B. subtilis YY-112 was lower than that of the co-FERSM with S.cerevisiae YY-21 (P < 0.05), and the reducing capacity of the FERSM was significantly higher (P < 0.05). The cells induced by d-galactose fed the rapeseed peptides produced from the FERSM and co-FERSM exhibited higher T-AOC and T-SOD capacity (P < 0.05) and presented lower concentrations of malondialdehyde (MDA) (P < 0.05), and the concentrations of MDA fed the peptides from the FERSM were lower than those from the co-FERSM. Overall, the novel fermentation method with screened Bacillus subtilis YY-112 and optimized extrusion conditions were effective in improving the antioxidant activity and anti-aging activity in vitro, thereby increasing the added value of RSM.