Water Absorption of RD31 Paddy During Soaking in Parboiling Process

Abstract

RD31 rough rice was soaked in water at several temperature levels and a change in moisture content of rice during soaking was examined. Moisture content of rice rapidly increased at initial of soaking but increasing rate of moisture content decreased with soaking time. Water absorption of newly-harvested rice was higher than aged rice at soaking temperature which was lower than gelatinization temperature (GT). However, for soaking temperature above GT, water absorption of the aged rice was higher than the newly-harvested rice. Either Becker’model or Peleg’s model could be used for predict moisture content of rough rice during soaking, except at soaking temperature which was higher than GT, RMSE of the Becker’s prediction model was lower than the Peleg’s model. Model’s paremeters of both prediction models were coincident with the hydration charecteristics of rice in the experiment.