Antioxidant properties of wheat bran FOs prepared by Bacillus amyloliquefaciens IT-45 fermentation

Abstract

As functional oligosaccharides, feruloyl oligosaccharides (FOs) exhibit the physiological activities of both ferulic acid and oligosaccharides. In this study, FOs were prepared by fermenting wheat bran with the generally recognised as safe (GRAS) bacterium Bacillus amyloliquefaciens IT-45. On the fourth day of fermentation, the activities of xylanase and cellulase reached 447.67 and 33.41 U/mL, respectively. UV, FTIR, and HPLC were used to characterise the structure properties of wheat bran FOs from B. amyloliquefaciens IT-45 fermentation. The monosaccharide compositions of FOs were mainly composed of xylose and arabinose. Under the optimal conditions of fermentation time of 4 days, fermentation temperature of 25 °C, initial pH of 6.5 and inoculation amount of 11% (v/v), the maximum yield of FOs in the broth was 0.6397 mM. In vitro antioxidant activity analysis showed that FOs prepared by B. amyloliquefaciens fermentation had good scavenging ability against ABTS, DPPH and hydroxyl radicals, demonstrating the application potential. The results provided a relatively environmentally friendly and food-safety way to prepare feruloyl oligosaccharides.