Effects of different treatments on composition, physicochemical and biological properties of soluble dietary fiber in buckwheat bran

To take better advantage of the soluble dietary fibers (SDF) of buckwheat bran, different treatments including extrusion, steam explosion, microwave, roasting, superheated steam, ultrasound and enzymolysis were applied to buckwheat bran, and the monosaccharide compositions, structural, physicochemical and biological properties of SDF were estimated. Except enzymolysis treatment, all the other treatments have significantly increased (p < 0.05) the content of SDF in buckwheat bran. Compared to natural SDF, the SDF in treated buckwheat bran showed porous and wrinkled surface, lower crystallinity, increased thermal stability and better rheological and hydration properties. These treatments have significantly improved the glucose adsorption capacity, nitrite ion adsorption capacity, antioxidant and antibacterial properties of SDF of buckwheat bran, among which extrusion showed the best effect. The microstructure, molecular size, monosaccharide and bound phenolics composition of SDF in buckwheat bran were effectively modified by appropriate treatments, with preferable physicochemical and biological properties.