Applying a wet-type grinder to wheat bran for developing breads

Wheat bran, the residue of the production of wheat flour, is rich in dietary fibers (DFs). Despite its high DFs, brans are scarcely used as a food source as the DFs in brans have adverse effects on food texture. Thus, improving the physicochemical properties of brans for various applications in foods is of great importance. Here, brans were atomized using a wet-type grinder (WG) that is commonly used to produce nanocelluloses. We treated 5 wt% brans with the WG. The particle sizes observed by a scanning electron microscopy and viscosity of WG-treated brans decreased and increased, respectively, with passages. In addition, the WG-treated brans also dispersed in water homogeneously, whereas untreated brans did not. WG-untreated or treated brans were used to replace 5% wheat flour to prepare breads. As compared to untreated bran replaced bread, bread loaf volume and crumb hardness of WG-treated bran replaced bread were higher and lower respectively. On the in vitro enzymatic digestion of starch, rapidly digestible starch of WG-treated bran replaced bread decreased by 40% than that of untreated bran replaced bread. These results indicate the possibilities that the WG can improve the physicochemical properties of brans and are useful to develop breads with added brans.