Influence of FIR irradiation on paddy moisture reduction and milling quality after fluidized bed drying Original Research Article

The influence of far-infrared (FIR) irradiation in multi-stage paddy drying process on moisture reduction and milling quality has been experimentally studied. The process, running in series, comprised fluidized bed drying, FIR irradiation, tempering and ambient air ventilation. The experimental results showed that the critical moisture content after the fluidized bed drying was around 23% d.b. whereas incorporating with the FIR irradiation could continuously reduced the moisture content to 21% d.b. without affecting paddy head rice yield and whiteness. Under the intensity of FIR irradiation, wet paddy was more sensitive than dry paddy. However, to maintain head rice yield, moisture equalization by a subsequent tempering stage was still required. Studying the microstructure of rice kernels and the pasting behavior of rice flours showed the presence of partial gelatinization resulted in the improvement of head rice yield.