Effects of ultrasound pretreatments on the quality of fried sweet potato (Ipomea batatas) chips during microwave-assisted vacuum frying

The research was focused on the quality of sweet potato chips fried by microwave-assisted vacuum frying (MVF) pretreated by ultrasound. Fresh sweet potato slices were pretreated at two different ultrasonic conditions: (1) ultrasound power of 150, 300, and 450 W for 20 min and (2) ultrasound power of 300 W for 10, 20, and 30 min. The pretreated samples were then fried by MVF. The dielectric properties, drying time, moisture content, oil uptake, texture, color, and microstructure profiles of the fried sweet potato chips were measured to determine the effects of ultrasound pretreatments on the quality of the fried sweet potato slices. This study found that the dielectric properties of the fresh sweet potato slices was significantly (