To build a model to describe the effect of microwave power(MW), air temperature (T) and rehydration time on WGR, the regression parameters were investigated. The experimental data for each rehydration experiment was fitted by nonlinear regression to Eq. (13). The value for equilibrium weight gain on rehydration (WGRe) was fairly constant over the range of experimental conditions studied. However, rehydration rate,kr, showed an increasing trend significantly with both MW and T. After careful inspection of a number of different candidate models, a linear model (see Eq. (14)) was found to best describe the dependence of kr on MW and T (r2> 0.95).