Effects of ultrasound frequency and application time prior to deep-fat frying on quality aspects of fried potato strips

It is well known that edible oil consumption and saturated fat intake in high amount are individually associated with important health problems such as obesity, coronary heart disease, and cancer. In recent years, ultrasound application prior to deep-fat frying has been proposed as an innovative emerging technology to reduce oil uptake. The objective of this study was to investigate the influence of various ultrasound frequency-time combinations on quality characteristics of potato strips during deep-fat frying. Results indicated that the potato strips subjected to ultrasonic waves at the frequency of 40 kHz for 30 min, exhibited the highest moisture diffusivity, resulting in the highest reduction in oil uptake (23.18%) among all the samples. Additionally, the ultrasound combined frequencies of 28 kHz (for 20 min) and 40 kHz (for 10 min) showed the best performance in reducing the shrinkage of fried products. Moreover, ultrasound frequency of 40 kHz for 30 min and also combined frequencies of 28 kHz (for 15 min) and 40 kHz (for 15 min) increased the apparent density of samples. In summary, by considering proper ultrasound frequency-time combinations, ultrasound application before deep-fat frying can be a promising approach to decrease oil uptake and shrinkage of fried potato strips.