Chiang Mai Journal of Science

This study examined the glycemic response of white rice to determine the effects of storage temperature (4°C, 0°C, and -20°C) and storage duration (1, 3, and 5 days). Results were compared with cooked white rice (control, 25°C). Measurements were performed on Days 1, 3, and 5 to test the glycemic index (GI), incremental area under curve (IAUC), and blood glucose response. Ten healthy adults aged 18-26 years were fed white rice or a reference food containing 50 g of available carbohydrates. Venous blood samples were collected before the meal and at 15, 30, 45, 60, 90, and 120 min after the meal. The results showed that the mean GI was highest for the control (93.5 ± 3.6), followed by those for the -20°C (87.4 ± 3.1), 4°C (84.1 ± 2.8), and 0°C (84.1 ± 2.7) test foods (Day 1). The mean GI of the 0°C test food decreased from 84.1 ± 2.7 on Day 1 to 77.9 ± 1.8 on Day 3 and then 74.8 ± 1.5 on Day 5. The GI values differed significantly with the storage duration (p < 0.05). In conclusion, white rice stored at 0°C for 5 days has the lowest glycemic response. Moreover, control group (25°C) exhibited the highest GI.