Physical modification of insoluble dietary fiber from Actinidia arguta pomace: structure, physicochemical properties, and multifunctional activities

Insoluble dietary fiber (IDF) from Actinidia arguta is a valuable functional food ingredient, but its inherent dense structure severely limits its functional properties and industrial application potential. In this study, IDF obtained via enzymatic extraction was used as the raw material to investigate the improvement effects of physical modification technologies on its comprehensive performance. Four physical modification methods, including microwave, ultrasound, high-pressure moist heat, and high hydrostatic pressure treatments, were applied. All treatments effectively disrupted the tight compact structure of unmodified IDF and promoted the exposure of internal active groups, thus significantly enhancing the structural and functional properties of the fiber ( p < 0.05). Among the modified samples, microwave-modified IDF (WIDF) exhibited a well-developed honeycomb network structure and the best overall performance. Its water-holding, oil-holding, and swelling capacities increased approximately 1.5– to 2.1-fold compared with the unmodified IDF. The antioxidant activities were also considerably improved, with the hydroxyl radical scavenging rate showing the highest increase of 2.4-fold. In terms of adsorption capacity, WIDF showed a 4.7-fold increase in sodium cholate adsorption, and also exhibited enhanced binding capacities for cholesterol, glucose, nitrite, and heavy metals in a pH-dependent manner. Microwave-modified IDF holds promising potential as a multifunctional food ingredient. This study provides a feasible approach for the high-value valorization of fruit processing by-products, which is conducive to promoting the sustainable development of the food processing industry. Insoluble dietary fiber from Actinidia arguta pomace: physical modification, structural characterization and functional properties. Created with https://BioGDP.com [1]