LAUSR

Abstract This study investigates the feasibility of achieving one-pass drying of high moisture content (MC) rice with microwaves (MWs) set at 915 MHz. Medium-grain rough rice at initial MC of 23% wet basis was dried using a MW dryer set to transmit energy at power levels 5, 10, and 15 kW for 4, 6, and 8 min for rice bed thicknesses of 5, 10 and 15 cm. Increasing MW specific energy up to 900 kJ/kg-grain resulted in increasing rice final surface temperature (FST) and drying rate which together had the effect of lowering the milled rice yield (MRY) and head rice yield (HRY). There was a statistically significant disparity in HRYs across the studied rice bed thicknesses. At the 10 to 15 cm (top) layer, the highest HRYs were observed (64.52%). The 0 to 5 cm (bottom) and the 5 to 10 cm (middle) layers had statistically similar mean HRYs that were both lower than the top layer.