Enhancing functionality of citrus fibers from peel and pulp pomace via combined alkaline hydrogen peroxide and xylanase modification

This study focused on enhancing the functionality of citrus fibers from peel and pulp pomace through physical, chemical, enzymatic, and combined modification methods. The primary aim was to increase the soluble dietary fiber (SDF) content while improving physicochemical properties such as water holding capacity, oil holding capacity, and thermal stability. The combined alkaline hydrogen peroxide and xylanase treatment emerged as the most effective method, significantly increasing SDF content from 9.67 % to 31.45 % and modifying the monosaccharide composition, especially with an increase in the ratio of arabinose to xylose. Structural characterization revealed substantial changes in the fiber's physical structure, such as enhanced porosity and specific surface area, without altering the fundamental chemical framework. Additionally, the modified citrus fibers exhibited notable improvements in thermal stability, with residual mass increasing from 10.22 % to 33.10 % at 600 °C. Furthermore, the water holding capacity and swelling capacity were enhanced by 123.61 % and 214.56 %, respectively. These findings provide valuable insights into the high-value utilization of citrus processing by-products and support the development of functional foods with enhanced nutritional profiles, highlighting the potential of modified citrus fibers in sustainable food industry applications.