Nutritional and structural changes in cooled rice

The texture and nutritional profile of rice change significantly as it cools due to a process known as starch retrogradation. While freshly cooked rice is soft and chewy because heat and water cause starch granules to swell (gelatinization), cooling causes amylose and amylopectin molecules to rearrange and form stronger bonds, making the rice harder.

Beyond texture, cooling rice can offer nutritional benefits. According to Dr. Võ Đăng Toàn from Tâm Anh General Hospital, cooled rice contains higher levels of resistant starch compared to freshly cooked rice. This type of starch acts similarly to fiber, passing through the small intestine to the colon where it is fermented by gut microbiota. This process produces short-chain fatty acids (SCFA), which provide energy to colon cells and support gut health.

Additionally, resistant starch is digested more slowly, which may help increase satiety and reduce appetite. However, experts warn that rice must be stored correctly; leaving rice at room temperature for extended periods increases the risk of bacterial growth and food poisoning.