Comparison of Three Different Frequency Drying Methods for Barley Chewable Tablets

Abstract

The effect of 27 MHz radio-frequency (27 RF), 915 MHz microwave (915 MW), and 2450 MHz microwave (2450 MW) on drying of barley chewable tablets was examined experimentally. It was observed that the dielectric constant was decreased with the moisture content reduction. Penetration depths of samples treated with 27 RF were the highest. The quality of products was evaluated according to color, temperature, ferric-reducing power, and DPPH scavenging. 2450 MW played a positive role in improving antioxidant properties. The comprehensive view is that radio-frequency technology may be a promising drying method for food processing.