Study On Quality Improvement And Prebiotic Activity Of Black Wheat Bran

Black wheat bran has higher content of dietary fiber,anthocyanin and polyphenol antioxidant substances,and has more advantages in nutritional function,but it is difficult to store and useless,because it is easy to rancidity,palate rough and poor taste.In this study,superheated steam treatment was used to reduce the lipase activity in the black wheat bran.Extrusion expansion and enzymatic technique were used to modify and ripen the black wheat bran.In addition,In vitro prebiotic tests were used to evaluate the prebiotic activity of the modified black wheat bran.The black wheat bran was treated by light rubbing and superheated steam technology.Under the condition of 4% ~ 6% rubbing rate,91.3% of lipase activity in the raw bran was reduced by the fast enzyme inactivation of superheated steam temperature 280 ? for 20 s,which significantly improved the storage stability and processing stability of the wheat bran.In order to ripen the bran materials and improve the content of soluble dietary fiber,the stabilized black wheat bran was extruded and treated with biological enzymatic methods.From the comprehensive quality evaluation of the product,the suitable conditions of extrusion and enzymatic hydrolysis were determined.The optimum conditions were 140? of area III temperature,0.6% xylanase,0.4% cellulase,24% water content,screw speed of 16 Hz.Under the optimum conditions,the content of soluble arabinoxylan(WEAX)was 3.159g/100 g.In vitro probiotic activities of improved black wheat bran were evaluated.After extrusion and enzyme treatment,the number of Bifidobacteria and Lactobacilli in the fermentation broth of black wheat bran increased by 56% and 38%,respectively.The content of short chain fatty acids(SCFA)in the fermentation broth increased significantly,the content of branched chain SCFA decreased significantly,the p H value decreased significantly.The results showed that compared with untreated black wheat bran,the probiotic effect of black wheat bran after compound modification was better.Compared with untreated black wheat bran,the prebiotic activity of stabilized and modified black wheat bran is improved.It can be developed and utilized as a nutritional powder and functional ingredient rich in dietary fiber prebiotics.