Abstract: The effect of dietary fiber (DF) and ferulic acid (FA) individually and in combination on the structure and properties of dough and gluten was examined. The results showed that addition of 3% to 12% DF significantly (P < 0.05) increased the water absorption, development time and breakdown viscosity of dough by 2.36%–7.76%, 18.15%–69.18%, 61.11%–283.33%, respectively, while addition of FA significantly increased the regeneration value by 90.48%–97.62%. The combined addition of DF and FA improved the effect of either alone on dough thermomechanical properties. The viscoelastic modulus of gluten with the individual addition of DF and FA was significantly higher than that of the control group, whereas the heat-denaturation temperature (Tp), heat denaturation enthalpy (ΔH), and disulfide bond content were significantly lower than those of the control group. In addition, the mass loss rate was significantly increased, indicating that the structural stability of gluten is decreased by the addition of DF and FA. The results of scanning electron microscopy showed that the smooth and orderly microstructure of gluten became loose and disordered after the addition of either DF or FA, while this change was reversed by adding them together.

Key words: dietary fiber, ferulic acid, thermomechanical properties, thermal properties, microstructure