Effect of Combined Frequencies and Applied Time of Ultrasound Pretreatment on Oil Uptake during Frying of Potato Strips

In recent years, the use of ultrasound is increasing due to its effectiveness in different food processing operations. The aim of this study was to investigate the combined effect of two ultrasound frequencies as a pretreatment on oil uptake during deep-fat frying of potato strips and to determine the optimal time to use these waves. In this study, ultrasound waves were used at frequencies of 28 and 40 kHz, separately and in combination, for 30 min. The use of ultrasound at both the frequencies, separately and in combination, reduced oil uptake. So that, the use of ultrasonic waves with a frequency of 40 kHz for 30 minutes showed the highest reduction in oil uptake by 23.19%. In addition, oil uptake was modeled as a function of time, moisture content, density and shrinkage. Several models were also proposed as a function of frying temperature, frying time, frequency and ultrasound time.