Abstract
The effect of gelatinization degree during cooking on the digestibility of cooked rice was investigated through a simulated gastro-intestinal in vitro digestion technique. The changes in starch hydrolysis percentage during simulated digestion were evaluated as a cooked rice digestibility in this study. Polished medium, non-waxy rice grain was soaked into boiling water as a model cooking. The boiling time was set at 10 and 20 min to obtain two gelatinized degree samples. Slurry samples were prepared from the grain samples to examine the impact of structural change of rice grain. The kinetics of cooked rice digestibility showed that there was no significant difference in the equilibrium starch hydrolysis percentage between the grain boiled for 10 min as a partially gelatinized sample and the grain boiled for 20 min as a completely gelatinized sample. However, the large difference between raw and boiled samples was shown. It was also shown that the equilibrium percentage of slurry was larger than the grain, even if the gelatinization degree was the same. These results indicated that the rice digestibility would be less affected by cooking conditions related with starch gelatinization except for raw materials, but should be influenced on the masticatory conditions connected to structural changes in the grain.
