The application of ultrasound for the regulation of the starch gel viscosity

Irina Kalinina, Alena Ruskina, Rinat Fatkullin, Natalya Naumenko, Irina Potoroko, Shirish Sonawane and Shabana Shaik

Abstract: The use of the ultrasonic exposure has an enormous potential for a wide range of processes in the food industry. Ultrasound allows modifying and improving the process characteristics of many food ingredients, widely used in food production. Among these food ingredients is potato starch. The purpose of this research is studying the influence of the low-frequency ultrasound on the viscosity of starch gel and the kinetics of changes in the properties of the starch gel depending on the time, the power of the ultrasonic exposure and the initial concentration of starch. The objects of the research are water solutions of potato starch exposed to ultrasonic treatment at the frequency of 22±1.65 kHz. To control the viscosity, we used SV 10 vibratory viscometer with the range of viscosities from 0.3 to 10000 mPa·s and the vibration frequency of 30 Hz. The viscosity measurement error is ±3%. It is established that the ultrasonic exposure can effectively increase or decrease the viscosity of starch solutions. Сhanging the time and the power of the ultrasonic exposure can help to reach a desired viscosity of the starch gel. The viscosity of the starch solution with the concentration of 5% can be twice increased in relation to the control sample while using ultrasonic treatment in the following conditions: power 120 W, exposure time 10 min (up to 20 mPa·s). It can be also reduced by 28-30% by increasing the ultrasonic exposure up to 20 min. The effects of reducing the amount of amylose in the starch gel are observed with an increasing power and duration of the ultrasonic exposure. Thus, ultrasound can be used to adjust the viscosity of starch solutions used in the food industries.

Keywords: physicochemical properties; potato starch; starch gel; viscosity of the starch gel

Date published: 2020-06-30