Kinetics of cooking unsoaked and presoaked rice

Cooking rate was examined for excess-water and optimal-water cooking of unsoaked and presoaked rice. The linear relationship between the logarithmic moisture gain ratios of cooked rice and the time of cooking showed that cooking rate followed the equation of a first-order chemical reaction. During excess-water cooking of presoaked rice a single rate constant was observed, while in the case of unsoaked rice two rate constants were observed. Interestingly, optimal-water cooking in electric rice cooker showed that the number of rate constants increased by one as compared to excess-water cooking for both unsoaked and presoaked rice. Controlled cooking, an energy saving method proposed earlier by the authors behaved similar to the normal method of cooking under otherwise identical conditions. Present evaluation of cooking rate constants under commonly practiced conditions of cooking would be useful in designing more efficient rice cookers.