Effects of combined radio frequency heating with oven baking on product quality of sweet potato

Abstract

As important primary food crops, sweet potatoes have rich nutritional values. Baking with a single oven is a common method for processing sweet potatoes. Since the single oven has some adverse effects on the product quality, radio frequency (RF) energy as a new heating technology was explored in combined baking with the traditional oven. Effects of single oven baking and combined RF and oven baking (RF-O) on baking time and product quality for cylindrical sweet potatoes were compared. Effects of electrode gap and sample diameter on RF heating rate and uniformity were also studied before comparing the baking characteristics between single oven and RF-O methods. Results showed that the best RF heating uniformity and acceptable heating time were obtained at an electrode gap of 90 mm and a sample diameter of 55 mm. The total baking time of 35.9 min for the single oven method was substantially reduced to 25.1 min for the RF-O method. Meanwhile, the sweet potato baked by RF-O had better color, or texture values, lower weight loss and lower acrylamide content than the single oven baking. Therefore, RF-O could be recommended as an effective, uniform, and high-quality baking method for sweet potatoes.