Abstract:The effects of different percentages of wheat gluten on the thermomechanical and dynamic rheological properties of wheat flour dough were studied by adding wheat gluten protein powder at substitution rates of 0%、5%、10%、15%、20%、25%、30%, by using Mixolab, a rapid visco analyser (RVA), and a dynamic rheometer. The results showed that with the addition of wheat gluten, the water absorption and the dough development time significantly increased from 53.3% to 67% and from 1.41 min to 9.31 min, respectively. On the other hand, the stabilization time first increased and then significantly decreased with increasing substitution rate, with the maximum stabilization time being 10.02 min at a substitution rate of 5%. The addition of wheat gluten significantly lowered the peak torque and setback value of wheat flour dough from 2.06 Nm to 1.37 Nm and from 1.68 Nm to 1.06 Nm, respectively. The dynamic rheological test revealed that the addition of wheat gluten greatly affected the viscoelastic properties of wheat flour dough. Both storage modulus (G′) and loss modulus (G〞) first increased and then decreased, while tanδ increased with the increase of wheat gluten percentage. The only exception was the dough with 5% wheat gluten protein powder, for which tanδ was lower than that of the control when scanned in the low-frequency range. The results indicated that the extent of molecular interactions increased, thus improving the strength of the gluten network of the flour dough.
