In vitro fermentation profile of soluble dietary fibers obtained by different enzymatic extractions from barley bran

The purpose of this study was to compare the fermentative properties of enzymatically extracted barley bran dietary fibers using a batch in vitro fecal fermentation method. Fibers with different β-glucan contents and molecular weights (Mw) were utilized. Fecal fermentation profiles were evaluated based on pH values, produced gas, total short chain fatty acid (SCFA), ratio and amounts of SCFA including acetate, propionate and butyrate during 6, 12 and 24 h of fermentation. The samples were compared with fructooligosaccharide (FOS) and blank for mentioned properties. Fiber extracted by α-amylase which had the lowest β-glucan purity (~55%) and the highest Mw (163 kDa) indicated the lowest gas production, the lowest amount of total SCFA production and the highest pH after 24 h of fermentation. On the other hand, Fiber extracted by α-amylase, protease and glucoamylase which had moderate β-glucan purity (~68%) and relatively low Mw (26 kDa), showed the greatest gas production, the highest total SCFA amount, the highest amounts of acetate, propionate and butyrate and the lowest pH, at the end of the fermentation period. This study helps to provide a new approach to obtain details regarding the fermentability of the enzymatically extracted dietary fibers.