Impact of cooling rates on the staling behavior of cooked rice during storage

The impact of cooling rates (0.40, 1.11, 1.42, 1.64, 2.47 and 3.36 °C/min) on starch retrogradation and textural properties of cooked rice was evaluated. The relationship between cooling rates and different properties were determined using Pearson correlation. Starch retrogradation enthalpy (ΔHr) of cooked rice was determined by differential scanning calorimetry, and textural properties were determined by a Texture Analyser. This study showed that the ΔHr value and hardness value had a negative correlation with cooling rate during storage, −0.963 ⩽ r ⩽ −0.716, P < 0.01; −0.826 ⩽ r ⩽ −0.706, P < 0.05, respectively. However, a positive correlation was found between adhesiveness and cooling rate (0.237 ⩽ r ⩽ 0.882, P < 0.05). These results indicated that the cooked rice chilled with slower cooling rate retrograded faster than chilled with rapid cooling rate. Therefore, high quality cooked rice can be produced by rapid cooling process.