Static and Dynamic Rheological Properties of Doughs Made from Rice and High-Gluten Wheat Flour Blends

The static and dynamic rheological properties of doughs made from six rice and high-gluten wheat flour blends were studied. In the dynamic rheological frequency sweep test, the storage modulus (G’) and loss modulus (G’’) of mixed doughs showed an overall upward trend with increasing amount of rice flour added, and the opposite trend was observed for tan δ. In the creep relaxation test, the maximum creep strain, maximum creep compliance and instantaneous recovery compliance gradually decreased, and the zero shear viscosity and instantaneous recovery ratio gradually increased. These observations indicated that the gluten in wheat flour was diluted after adding rice flour, but the starch granules in rice flour swelled and adhered to each other after absorbing water, and interacted with rice flour proteins, imparting higher elastic modulus and more internal structure to dough. In the dynamic rheological temperature sweep test, the viscoelasticity of mixed doughs was changed significantly before and after the gelatinization temperature, and the G’ and G’’ curves were similar to the starch gelatinization curve, indicating that starch was the major component affecting the rheological properties of raw dough during heating. The G’ and G’’ increased regularly in the high temperature zone, but decreased regularly in the low temperature zone below 60 ℃ during cooling. The samples had solid-like properties during the whole cooling process.