Insoluble dietary fibers from yellow- and purple-fleshed potatoes by-products and their physicochemical properties and structural characteristics: A comparative study

摘要

Potato is a widely consumed crop with a rich starch content, but many benefits of its by-products are still underutilized. To highlight its potential values, we extracted insoluble dietary fibers from yellow (YIDF) and purple (PIDF) fleshed potato by-products and evaluated their physicochemical, functional, and structural properties. Chemical compositions were significantly different between YIDF and PIDF. YIDF gave a higher water- (29.7 +/- 2.5g/g) and oil-holding capacities (14.3 +/- 1.4g/g), as well as emulsion stability. Although PIDF showed a stronger DPPH free-radical scavenging and -glucosidase inhibitory activities, ABTS and FRAP free-radical scavenging activities were similar to those of YIDF. Surprisingly, PIDF (0.17 +/- 0.01 GAE mg/g DF) did not give a higher total phenolic content than YIDF (0.24 +/- 0.01 GAEmg/g DF). Thermal property was different between YIDF and PIDF, and YIDF presented a more irregular, rough, and porous surface. It can be concluded that the obtained IDFs, especially for YIDF, can be used in the food industry as fiber-rich functional ingredients.