Comparative study of physicochemical properties of accelerated and naturally aged rice

The objective of this study was to accelerate the aging of "Thai jasmine" paddy via the use of a drying process, which consists of high-temperature fluidized bed drying followed by tempering and ventilation. Based on the experimental results it was found that the rice properties after processing, namely, elongation ratio, whiteness, volume expansion, water uptake, solids loss and pasting properties, changed in a similar fashion to those of the naturally aged paddy. The higher drying temperature, higher initial moisture content and longer tempering time significantly affected the aged rice properties. However, the head rice yield of rice undergone thermal processing was significantly lower than that of the naturally aged paddy. The drying temperature of 150 °C, initial moisture content of 33% (d.b.) and tempering time of at least 90 min were recommended as the most suitable conditions for accelerating the rice aging process.