The effect of removing bound polyphenols on the physicochemical and functional properties of Rosa roxburghii tratt dietary fiber in vitro

Abstract

Dietary fiber (DF), an indigestible component of plant cell walls, is widely recognized for its health benefits. Rosa roxburghii Tratt (RRT) pomace contains high levels of DF, known for their anti-inflammatory and antioxidant properties, which are beneficial in managing atherosclerosis and diabetes; however, knowledge about the DF in RRT is limited. This study aimed to determine whether bound polyphenols (BPs) contribute to the health benefits of RRT's DF and assess its potential as a valuable source of DF. DF was extracted from RRT (RRT-DF) using an enzymatic method and BPs removed from RRT-DF through alkaline extraction (RRT-DF-F), and the microstructural, physicochemical, antioxidant, and adsorption properties were compared between RRT-DF and RRT-DF-F. The results showed no significant alteration in the microstructure, crystalline peaks, or characteristic bonds of the obtained fibers, and RRT-DF showed improved water- and oil-holding capacities. RRT-DF-F demonstrated significantly lower DPPH and OH-scavenging activity than RRT-DF, and the adsorption capacity for nitrite, cholesterol, and bile acid, and the α-glucosidase activity inhibition ratio was significantly decreased. These findings indicate that BPs contribute to the in vitro physicochemical and functional properties of RRT-DF, highlighting its potential as a functional food ingredient and supporting the high-value utilization of RRT byproducts.