Effects of insoluble dietary fiber and ferulic acid on the rheological properties of dough

This study sought to investigate the effects of insoluble dietary fiber (IDF), ferulic acid (FA), and a combination of the two (IDF + FA) on the rheological properties of dough. When the amount of IDF was increased from 2 g to 12 g, the water absorption rate of the dough increased by 14.33%. However, when FA within the dough was in the range of 61.6%–63.1%, the dough's water absorption rate was lower than that of the control sample, which might be related to FA inducing the breakdown of the dough. The dough that included IDF was associated with a higher stability time, a higher C2, and a lower development time due to the dilution effect of IDF, which weakened the gluten but increased the mechanical resistance of the dough. FA not only reduced the dough's development time and stability, but also reduced its C2 due to the crosslinking reaction with gluten. Moreover, IDF reduced the gelatinization properties of the starch and the stability of the hot-formed gel. In addition, it inhibited starch retrogradation in the dough. Due to the strong water absorption and filling effects of IDF, the elastic modulus (G′) and viscous modulus (G″) of the dough increased, although the creep strain decreased. The effects of the IDF + FA combination might be due to the crosslinking reaction of IDF-FA and IDF-FA-gluten, which reduced the plasticizing effect of the water, further increased the viscoelasticity and reduced the creep strain of the dough.