Physicochemical properties of insoluble dietary fiber from pomelo ( Citrus grandis ) peel modified by ball milling

This work is focused on the modification of insoluble dietary fiber from pomelo (Citrus grandis) peel (PP-IDF) by ball milling. Ball milling intensified water and oil holding capacity and water swelling capacity by 43.7%, 65.1%, and 107.5%, respectively. Besides, 97.1% of taurocholic acid, 45.3% of glucose, and 9.3 μg/mg of NO2− were bound by milled insoluble dietary fibers (IDFs). The oil-in-water Pickering emulsions were successfully emulsified by ball-milled PP-IDFs. The ball-milled PP-IDF for 2.0 hr (PP-IDF-BM2h) exhibited higher stability after storage owing to its relative strong electrostatic and steric repulsions intensified by milling process. A simulated three-stage gastrointestinal tract (GIT) model was employed to explore the physical stability of emulsion in the digestive system. Ball milling contributed promotion on stability emulsion but ion strength in simulated liquids predominated in affecting ζ potential. Overall, ball milling extended green protocols for modification of properties for dietary fiber, providing a promising application in food industry. Practical applications For safety consideration, materials used for food processing should be in low toxicity with less employment of chemicals. Hence, it is essential to develop a green and renewable strategy to modify properties of dietary fiber (DF) in food applications. Ball milling is a simple and low cost strategy that can effectively improve or modify physicochemical properties including crystallinity, surface potential, water and oil holding capacities, and hydrophilic and hydrophobic properties. Importantly, ball milling can treat dietary fiber in batch processing with no waste and chemicals, which is suitable for industrial applications.