The effect of xanthan and sucrose on the physicochemical, rheological and morphological properties of wheat and corn starches

The increase in the need for starch in the food processing industry has led to the recognition of the effect of other food compounds on the processing of starch-based foods. Xanthan and sugar are commonly used as hydrocolloids and sweeteners, respectively, in starch-based foods. These constituents can affect the structural, thermal, adhesive (dough) and rheological properties of these types of foods. The purpose of this study is to analyze the effect of sucrose and xanthan on the physicochemical, rheological and morphological characteristics of starch pastes. In addition, the comparison of the effect of the combination of xanthan and sucrose on corn and wheat starch pastes has been done in this study. In this research, the concentration of xanthan was 1% by weight and sucrose was 5% by weight, and the mixtures were prepared based on starch (corn or wheat starch). The results showed that in the presence and absence of xanthan 1% by weight and sucrose 5% by weight, the starch dough had a significant difference in terms of solubility, swelling power, water absorption, and dough transparency (p < 0.05). Rheological tests revealed that all pastes exhibited shear thinning behavior. By adding xanthan and sucrose, the apparent viscosity, storage modulus and loss modulus of starch pastes increased. Fourier transform infrared spectra showed the change in the intensity and wavelength of absorption peaks due to the addition of xanthan and sucrose. The measurements of scanning electron microscope and X-ray diffraction proved that as a result of adding xanthan and sucrose during gelatinization, changes were made in the network structure. The results of this study can improve processing and find optimal processing conditions to produce food based on Starch like baby food, bread, sweets, etc. help.