# Comparison of Structural, Physicochemical, and Functional Properties of Blueberry Residue Dietary Fiber Extracted by Wet Ball Milling and Cross-Linking Methods

## TL;DR

This study compares two methods for extracting dietary fiber from blueberry residue and finds that wet ball milling improves its functional properties for food use.

## Contribution

The novel contribution is demonstrating that wet ball milling enhances hydration and adsorption capacities of blueberry residue dietary fiber.

## Key findings

- Wet ball milling significantly reduced particle size and increased pore formation in dietary fiber.
- Wet ball milling improved hydration and adsorption capacities compared to cross-linking.
- Cross-linking increased thermal stability and crystallinity of dietary fiber.

## Abstract

This study evaluated the structural, physicochemical, and functional characteristics of blueberry residue dietary fiber (DF) extracted by wet ball milling (WB) and cross-linking (C) treatments. The particle size of WB-DF showed a significant decreasing trend (p ≤ 0.05) compared to that of C-DF and blueberry residue. Scanning electron microscopy (SEM) demonstrated that WB treatment unfolded the flaky structure of DF and caused more pores to occur. The results showed that the modifications of WB increased the release of active groups and enhanced the hydration and adsorption capacities. X-ray diffraction (XRD) analysis showed the highest crystallinity observed for C-DF, resulting in the increased thermal stability of C-DF. The molar ratios of monosaccharides were also influenced by different modification techniques. In addition, WB-DF showed the lowest ζ-potential and highest viscosity among all samples. Conclusively, DF extracted by WB treatment exhibited remarkable application potential in the functional food industry.