Characterization Of Dietary Fiber And XOS Extraction From Wheat Bran

Wheat bran contains 45-50% of fiber, which is recognized as a good source of dietary fiber and oligosaccharides. Besides of dietary fiber, wheat bran riches starch, protein etc. so eliminating the starch and protein with low-energy, quickly and effectively is the key technology which is made of dietary fiber. At first, the best technology how to make dietary fiber by enzyme was studied, then the physicochenmical of the dietary fiber made by different methods were studied, what is more, the best technology how to make XOS from dietary fiber of wheat bran by Ultrasonic-enzyme.The composition of wheat bran was analysized as 17.92% starch, 16.10% protein,45.12% the total dietary fiber(TDF), including 40.26% the insoluble dietary fiber(IDF), but the content of fat and ash is more less, 3.47%,4.68%, respectively. the starch was separated by medium amylase and glucoamylase. Taking the residual of starch of wheat bran as a target to find the best technology by the experiments of single factor and orthogonal tests.The best optimum conditions were:the ratio of stuff and liquid was 1:12(g/m L),the proportion of α-amylase and diastase was 4:3, the enzyme concentration was 0.8% relative to the wheat bran, the reaction time was 70 min, the p H was 5.0. The residual of starch reduced to 0.57% from 17.92%.. The hydrolysis was performed with alcalase concentration 0.4% at 60 and he ratio of stuff and l℃ iquid 1:14(g/m L)and the reaction time 90 min and the p H 8.5. The residual of protein reduced to 3.54% from 16.10%. The concentration of total dietary fiber was 86.23% including 78.0% the insoluble dietary fiber and 8.23% soluble dietary fiber.The study compared the concentration of total dietary fiber in which were made by four different ways, including acid-alkali, acid-enzyme, enzyme-alkali, enzyme, etc. The proportion of total dietary fiber is 86.00%, 80.34%, 69.33%and 59.00%, respectively. The arranged in order of the capacity of removing DPPH is enzyme-enzyme, enzyme-alkali, acid-enzyme, acid-alkali, especially, the capacity of removing DPPH of the enzyme-enzyme and acid-alkali was 84.78%, 49.18%, respectively.the best technologywas discussed which made xylooligosaccharides from the dietary fiber. the ratio of stuff and liquid was 1:25(g/m L), the ultrasonic of temperature was 30 ℃, the time of ultrasonic was for 45 min, the power of ultrasonic was 450 W, the maximum of sugar yield was achieved 3.53g/L, and the relative content of xylobiose and xylotriose were achieved 762.27, 228.64mg/m L, when the p H of suspension was adjusted 5.6 with 15 m L xylanases which is 3.0g/L, after incubation at 52 ℃ for 10 h. The antioxidant capacity of removing radicals OH-, DPPH, O2-were 84.66%, 81.87%,85.90%, respectively when the degree of xylooligosaccharides was 3.g/L.