Effect of drying conditions on the quality of IRGA 424 rice

The objective of this research was to investigate the effects of drying temperature (40, 50, and 60 °C), tempering time (40, 80, and 120 min), and initial moisture content at onset of tempering (15, 17, and 19% dry basis) on head rice yield, milled rice yield, and total processing time of IRGA 424 rice.

The most significant effects were the drying temperature and its interaction with initial moisture content at onset of tempering. The optimum conditions predicted to reach the highest total yield (74.1%) included drying at 46.6 °C, 49 min of tempering time, and initial moisture content at onset of tempering of 19%. To achieve the maximum value of whole grain yield (52.9%), drying at 40 °C, 40 min of tempering, and an initial moisture content of 19% at the initiation of tempering were required. Under these conditions, the grain reached a moisture content of 13% in 84 min.

Whole-grain rice yields may be maximized through the optimization of the drying process. This may result in a larger fraction of the crop entering the human food chain, enhancing the value of the crop, and resulting in a smaller fraction of broken grain, which commands a lower market value. © 2018 Society of Chemical Industry.