Microwave drying of cooked brown rice and the effect on the nutrient composition and trace elements

The objective of this work was to study the effect of a new low temperature drying system by continuous and instant microwave power control on cooked brown rice. The drying system was operated in the microwave power range of 280 W to 320 W. Samples of cooked brown rice (4 cm diameter x 1 cm high) were used. The optimum drying was at 300 W for 48 min. The changes in the nutrient composition and trace elements of the cooked brown rice, resulting from before and after microwave drying at 300 W for 48 min, were then analyzed. No change of crude protein, ash, crude fiber, and carbohydrate was observed in the cooked brown rice both before and after drying (P 0.05) though a little crude fat change was found (P 0.05). Simultaneously, no explicit changes were found regarding the potassium (K), magnesium (Mg), and zinc (Zn) levels after the drying (P 0.05). It is demonstrated that by this drying method brown rice retained its fresh nutritional value and mineral content.