Physicochemical, functional, and antioxidant properties of dietary fiber from Rosa roxburghii Tratt fruit modified by physical, chemical, and biological enzyme treatments

To improve the physicochemical, functional, and antioxidant properties of dietary fiber from Rosa roxburghii Tratt fruit (RIDF), the effects of physical, chemical, and biological enzyme treatments were investigated. Three modification methods significantly reduced the particle sizes and increased the content of soluble fiber of RIDF. The crystallinity and thermal stability of RIDF fractions after modification were changed. Functional analyses showed that complex enzymatic hydrolysis effectively enhanced the water-holding capacity, water-swelling capacity, oil binding capacity (OBC), cation exchange capacity (CEC), glucose absorption capacity, nitrite ion absorption capacity, and cholesterol absorption capacity of native RIDF. Dynamic high-pressure microfluidization remarkably improved the total phenol content and antioxidant abilities. Furthermore, carboxymethylation caused a significant increase in the OBC, glucose absorption capacity, and CEC of native RIDF. These results suggest that the modified RIDF, especially for complex enzymatic hydrolysis, can effectively improve the physical, chemical, and functional properties of the fiber. Practical applications Due to poor processing adaptability, the high content of dietary fibers from R. roxburghii fruit are usually discarded in the fresh fruit juice process. This study aims to explore the effects of three modification methods on the physicochemical, functional, and antioxidant properties of RIDF, thus it can be used for partial incorporation in food, functional food, and medicine. As a good source of dietary fiber, modified RIDF, can be added in a variety of foods to make these products have the function of resisting various diseases.