Physicochemical properties and structural characteristics of soluble dietary fibers from yellow and purple fleshed potatoes by-product

摘要

We extracted soluble dietary fiber from yellow (YSDF) and purple (PSDF) fleshed potatoes by-product to compare their physicochemical properties and structural characteristics. YSDF and PSDF showed similar monosaccharide compositions. YSDF gave a higher oil-holding capacity and swelling capacity (15.6?±?1.1?g/g, 18.7?±?0.8?mL/g) than PSDF (12.5?±?0.9?g/g, 13.5?±?1.0?mL/g). Emulsifying activity and emulsion stability of YSDF (33.8?±?1.4?mL/100?mL and 31.5?±?0.3?mL/100?mL, respectively) were significantly higher than those of PSDF (24.8?±?1.1?mL/100?mL and 19.6?±?1.8?mL/100?mL, respectively). Although PSDF showed a stronger DPPH (1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate)) free radical-scavenging activities (0.18?±?0.01 and 2.39?±?0.20?mg Trolox/g SDF), FRAP (ferric-reducing antioxidant power) free radical-scavenging activity was similar to that of YSDF. Furthermore, molecular weight of YSDF (3967.3?Da) was lower than that of PSDF (4462.8?Da). Thermal property was different between YSDF and PSDF, and YSDF presented more rough, irregular, and porous surface. It can be concluded that SDFs from yellow fleshed potatoes are more suitable to use as fiber-rich functional ingredients.