Structural, physicochemical and functional properties of dietary fiber from brown rice products treated by different processing techniques

Brown rice is rich in dietary fiber and polyphenols, which have unique health benefits. Rice is usually eaten after cooking, and the change of physicochemical and functional properties of DF will directly affect the quality of brown rice products. This work aimed to investigate the effects of different processing techniques on the structure, physicochemical and functional properties of dietary fiber (DF) from brown rice (BR) products. DF samples were extracted from cooked germinated BR (GBR), fermented BR (FBR) and extruded BR (EBR). The results indicated that the particle size of DFs from three processed BR products decreased. Moreover, the waterholding capacity (WHC), oil-holding capacity (OHC), swelling capacity (SC), glucose adsorption capacity (GAC) and antioxidant capacity of three DF samples were improved. The DF from EBR possessed more porous structures, smaller particle size and lower crystallinity. Notably, the DF from EBR demonstrated the highest WHC, OHC, SC, GAC and antioxidant capacity. In conclusion, extrusion is a good way to promote the nutritional and functional properties of DF extracted from processed BR products. These results might provide basic information to help better understand the functionality of DF from cooked BR, and promote the development of brown rice foods with high nutritional qualities.