Abstract:Using wheat bran insoluble arabinoxylan as raw materials for preparation of xylooligosaccharides by enzymatic hydrolysis, the effect of enzymolysis temperature, enzymolysis time and enzyme dosage on the content of xylooligosaccharides, sugar composition, average polymerization degree and prebiotic activity were studied. The results showed that the content of xylooligosaccharides increased, while the average degree of polymerization and the relative content ratio of xylose, xylose and xylose decreased when the enzymolysis time increased from 1 h to 2 h, the hydrolysis temperature increased from 40 ℃ to 50 ℃ and the amount of enzyme increased from 0.125 to 1 g/L. When Bifidobacterium adolescentis was cultured with xylooligosaccharides obtained under different enzymolysis conditions, the concentration of Bt increased in different extents. The metabolites of fermentation broth contained lactic acid, acetic acid and propionic acid, and the content of acetic acid was the highest. The trend of acid production was consistent with the concentration of bacteria and the content of xylooligosaccharides, while contrary to the average polymerization degree of xylooligosaccharides. The content of xylooligosaccharides reached to 101 mg/g, the average degree of polymerization decreased to 3.23, the relative content ratio of xylose, xylose and xylose was the smallest, and the multiplication of cell concentration was up to 5.65 times when the enzymolysis temperature was 50 ℃, the time of enzymolysis was 2h and the amount of enzyme was 1 g/L.