Impact of ohmic heating and ultrasound pretreatments on oil absorption and other quality parameters of fried potato

Abstract

In this study, the effect of pretreatments ((hot water blanching (HWB), ultrasound (US) and ohmic heating (OH)) on reducing the oil absorption of potato during frying and the changes in the quality parameters of the product ((total polyphenol (TP), in vitro digestion, total flavonoid (TF), antioxidant capacity (AC), chlorogenic acid (CA), textural and sensorial properties)) were investigated. The pretreatments applied significantly affected oil absorption and quality parameters of fried potato. The oil content of fried potatoes ranged from 26.06 to 32.01% depending on the pretreatment. OH-pretreated potato had the highest content of TP (41.27 mg GAE/100 g dry matter-DM), TF (32.89 mg RE/100 g DM) and CA (1.72 mg/100 g DM). However, there was no significant difference between the pretreatments in terms of bioaccessibility of polyphenols at the end of digestion. Also, AC value of fried potato pretreated by OH (124.13 mmol AAE/100 g DM) was higher compared to that of fresh potato (83.91 mmol AAE/100 g DM), but other two pretreatments caused a decrease in AC. The highest hardness was observed in HWB-treated potato strips. OH-treated potato had the best color parameters. Sensory data indicated that US-pretreated potato had the highest sensory scores followed by OH- and HWB-pretreated ones, respectively. Consequently, based on the above comprehensive quality evaluation, it can be suggested that OH pretreatment is a better choice for preparing deep fried potato.