Influence of a three stage hybrid ultrasound-osmotic-frying process on production of low-fat fried potato strips

Fried potato is one of the most consumed products in the world. Due to consumers' growing tendency to use healthy and low-fat foods, reducing oil content in fried foods has become a necessity. Several studies have shown that higher initial water content results in increased oil uptake during frying. Therefore, pretreatments that reduce water content of the product could lower oil uptake in the final product. The aim of this study was to evaluate the influence of a three-stage hybrid ultrasound-osmotic-frying process on production of low-fat fried potato strips.

Results showed that, compared to control samples, osmotic pretreated samples using saline solutions at concentrations of 2% and 4% decreased oil uptake by 29.5% and 32.7%, respectively. Ultrasound (28 and 40 kHz) also showed a significant synergistic effect on reducing oil uptake in the samples pretreated with both ultrasound and osmotic dehydration so that different samples pretreated with both ultrasound and osmotic dehydration decreased oil uptake from approximately 40% to more than 50%, compared to untreated control samples.

Owing to production of low-fat fried potato strips, utilising osmotic dehydration pretreatment was desirable before the frying process. Regarding low mass transfer rate during osmotic treatment, ultrasound was applied to enhance mass transfer rate. The use of ultrasound pretreatment in the frying process can yield promising results in reducing oil uptake. © 2017 Society of Chemical Industry.