Modeling of rice hydration using finite elements

Great effort has been devoted towards developing models that describe cooking processes. A difficulty towards developing such models arises from the fact that during cooking, the physical properties and quite often sample geometry are time dependent. In this work a finite element model describing cooking of rice and water uptake using a Fickian diffusion model was developed, assuming axisymmetric conditions. Effective diffusivity was considered a function of moisture content. The numerical model compared favorably with experimental results. The value of the effective water diffusivity was estimated to be in the order of 7 × 10⁻¹⁰ m²/s, by minimizing the error between experimental and numerically predicted results.The effect of grain size on the cooking was also investigated using the model. Cooking time, i.e. the time to reach about 70% moisture content (wet basis), appeared to be a strong function of the initial size distribution.