Abstract
In the present work, a three-dimensional (3D) replica of rice geometry was reconstructed from tomographic images and applied to model the diusion of moisture in rice grains. The purpose of this study was to determine the diusion coecient of rice using reconstructed 3D geometry. As for a constant diusivity model, the modeling of water absorption was based from experimental data of moisture diusion in rice soaked at various temperatures (25,35 and °C). Results showed that the calculated diusion coecient at each respective temperature had Arrhenius-type temperature dependency. Comparison between the calculated diusion coecients for reconstructed rice geometry with diusion coecients using an innite plane sheet and sphere diusion models was shown to be satisfactory in describing the moisture diusion characteristics of rice. We also developed a moisture sorption model with variable diusion coecient as a function of temperature and moisture content.
