Document Type : Original Article

Authors

Abstract

Determination of the proper drying methods of rough rice is one of the effective factors on reducing the grain losses. In this study effect of air temperature in three levels (40, 50 and 60 °c) equivalent radiations intensity (0.031, 0.042 and 0.053 w.cm-3) and paddy final moisture in three levels (8-9, 9-10 and 10-11% d.b.) on the drying time and rice milling characterization of Domsiah variety were examined in the fluidized bed dryer with two thermal sources; infrared radiation and warm air stream. The experiments were conducted in factorial layout based on completely randomized design with three replications. The results indicated that the effects of air temperature and drying method on the broken grains, cracked grains and drying time was significant (P<0.01). With increasing the air temperature from 40 to 60 °c, the cracked percent (from 5 to 14%) and broken grains (from 26 to 39 %) increased and drying time (from 964 to 242 min) decreased. In each level of air temperature, the cracked grain and broken grain at the moisture content 8-9% and air temperature of 40 °c  in the infrared dryer was minimum (5.67 and 26.9%, respectively) and it was maximum at the moisture contents of 8-9% and air temperature of 60°c  (14 and 39.5%, respectively).

Keywords

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