Influence of ultrasound effects on the rheological properties of the potato starches paste

To improve the technological characteristics of starches, which are used in the food industry, viscosity control is one of the most promising areas that should be considered, since starch is primarily used as a natural thickener and emulsifier. At temperatures of 58-65 °С and above, the process of potato starch gelatinization occurs with the subsequent formation of hydrogels. Ultrasound can effectively reduce the viscosity of starch solutions after gelatinization. The advantages of ultrasound exposure are the following: the process does not require the use of any chemicals and additives; the process can be simple and fast; the process does not cause major changes in the chemical structure of starches but only affects its rheological properties. The effectiveness of ultrasound exposure was evaluated by measuring the changes in viscosity and emulsifying ability of starch paste. The change in the molecular weight of starch, and hence the emulsifying ability, was monitored by an SF-56 spectrophotometer. Ultrasound exposure can be applied to many types of starch (corn, tapioca, wheat, etc.), our research is aimed at potato starch, due to the fact that the Ural region is a favourable area for the cultivation of potatoes, including as a source of starch. The results obtained suggest a decrease in the viscosity of potato starch paste after gelatinization under the influence of ultrasound. Emulsifying activity in samples treated with ultrasound is 2-3 times higher, is evidence that physical and chemical parameters change, namely the structure and size of starch grains, which leads to an increase in their homogeneity, a decrease in molecular weight and an increase in the ability to form lower molecular units.