- A two-dimensional diffusion equation was solved by the finite element method to estimate transient moisture gradients in the endosperm of a rice grain. Moisture elevated samples of 150 rough rice grains were dried for different durations with different air temperatures. Fissured grains were counted immediately after drying and at periodic intervals of 12 h. High initial moisture contents and high drying air temperatures caused the most fissured grains. Transient moisture gradients at several locations of the rice endosperm are presented at selected periods during and after drying. The relationships between the transient moisture gradients and the resulting fissured grains are explained. 1996 American Society of Agricultural Engineers.