Effects of insoluble dietary fiber and ferulic acid on the quality of steamed bread and gluten aggregation properties

The effects of insoluble dietary fiber (IDF) and ferulic acid (FA) on steamed bread quality and gluten aggregation properties were investigated. IDF and FA increased the hardness and decreased the specific volume of steamed bread, except for 0.3 g of FA. Compared to the control sample, the hardness of steamed bread with 0.3 g of FA decreased by 36%, and the specific volume increased by 10.91%. FA promoted gluten aggregation through a cross-linking reaction because the sodium dodecyl sulfate extractable protein (SDSEP) of gluten with 1.8 g of FA decreased by 61.32% compared to the control sample under non-reducing condition. The ζ-potential of gluten during the proofing and steaming stages decreased by 46.64% and 68.10% with the increase in IDF, which showed that IDF promoted gluten aggregation by reducing the electrostatic repulsion. Gluten aggregation caused by IDF and FA could be the main reason for steamed bread deterioration.