Effects of Modified Wheat Bran Insoluble Dietary Fiber on Properties of Starch and Protein

ABSTRACT Background and Objectives With the rise of healthy eating, fiber‐rich foods are gaining more attention. Insoluble dietary fiber (IDF) is widely used for its physiological benefits and nutritional value. However, it can negatively affect food quality, which limit its application. This study aims to enhance wheat bran IDF′s processing properties through modification (alkaline hydrogen peroxide treatment, hydroxypropylation, and esterification) and explore how native and modified IDF influence the characteristics of wheat starch and protein. Findings DSC and RVA results showed that IDF reduced Δ H , improved thermal stability, and inhibited starch retrogradation, with effects strengthening as IDF content increased. IDF lowered freeze–thaw stability, modification can reduce water precipitation. Upon IDF addition, disulfide bond (S─S) and β‐sheet content first increased then decreased, while β‐turn content first declined then rose. CIDF achieved the greatest starch order and double helix structure, along with the highest S─S content, at 5% addition, whereas modified IDF performed best at 10%. Conclusion Modification can improve the processing performance of IDF and increase its addition amount in flour‐based products. Significance and Novelty This study provides a theoretical basis for the development of dietary fiber products and functional foods.