Moisture Removal Characteristics of Thin Layer Rough Rice Under Sequenced Infrared Radiation Heating and Cooling
The objective of this study was to investigate the moisture removal characteristics of thin layer rough rice heated by infrared (IR) and cooled with various cooling methods. Thin layer rough rice samples with different initial moisture contents (MCs) were heated using a catalytic IR emitter for four exposure times and radiation intensities. High heating rate and moisture removal were achieved during the IR heating period. After heating, more moisture removal was achieved during the cooling period. The achieved grain temperatures ranged from 35.1 to 68.4C under the tested heating conditions. The vacuum and forced air cooling methods removed more moisture than did the natural cooling. When rice with 25.7% MC was heated by IR, MC was reduced by 3.2, 3.5, and 3.8 percentage points for rice heated to 63.5C at the IR intensity of 5348 W/m2 for120 s followed by natural cooling for 40 min, forced air cooling for 5 min and vacuum cooling for 10 min, respectively.