Abstract:
To explore the efficient preparation method and biological activities of feruloyl oligosaccharides (FOs) from rice bran, FOs were prepared by mixed fermentation of
Lactobacillus plantarum and
Bacillus licheniformis using rice bran as raw material. The fermentation conditions were optimized and the structure and biological activities of FOs were analyzed. The results showed that the optimal fermentation conditions were inoculation ratio of 3:7, inoculation amount of 1×10
8 CFU/mL, solid-liquid ratio of 1:3 (g/mL), and fermentation for 3 days. Under these conditions, the content of FOs reached 64.9 μmol/L. The structure of fermented rice bran and FOs was analyzed by scanning electron microscopy, ultraviolet, infrared spectroscopy and liquid chromatography-mass spectrometry. The results showed that the mixed fermentation destroyed the cell wall structure of rice bran, and the prepared FOs were feruloyl esterified oligosaccharides, mainly composed of feruloylated arabinooligosaccharides, xylo-tetraose and xylo-pentaose. The inhibitory rates of FOs on
α-amylase and
α-glucosidase were 58.34% and 95.70%, respectively, which could significantly reduce the hydrolysis rate of rice starch (
P<0.05), with a reduction of 6.39%. The scavenging rates of DPPH and ABTS
+ free radicals were 78.15% and 87.80%, respectively, and it could inhibit the formation of advanced glycation end products (AGEs), with an inhibition rate of 75.45%. This study provides a theoretical basis for the green preparation of FOs and the efficient utilization of rice bran resources.