Physicochemical, functional and biological properties of soluble dietary fibers obtained from Rosa roxburghii Tratt pomace using different extraction methods

Rosa roxburghii fruit pomace is an abundant, but underutilized, byproduct from the juice industry. In this study, the effects of different extraction methods on physicochemical, functional and biological properties of water soluble dietary fibers (SDFs) extracted from R. roxburghii Tratt pomace were compared. The SDFs, named RWSDF, RXSDF and RCSDF, were extracted from R. roxburghii Tratt pomace by water extraction, xylanase extraction, and cellulase extraction methods. Results indicated that RWSDF, RXSDF and RCSDF varied in chemical and monosaccharide compositions. The structural results indicated that RWSDF, RXSDF and RCSDF exhibited similar spectral characteristics of polysaccharides. Compared with RWSDF, RXSDF and RCSDF exhibited higher crystallinity, higher thermal stability, and more porous structures. Furthermore, RXSDF and RCSDF showed higher water-holding capacity, oil-holding capacity, water solubility, nitrite ion absorption capacity, antioxidant activity, and α-glucosidase inhibitory activity. These findings suggest that RRTP may be a potential functional food and a promising natural source of dietary fiber.