Effect of cooling rate on the retrogradation properties and quality of refrigerated dry-steamed fried rice

Abstract

The cooling rate is an important factor affecting the quality of refrigerated fried rice. The effect of the cooling rate (0.16°C/min, 0.78°C/min, 1.66°C/min) on the retrogradation properties of dry-steamed fried rice during the refrigeration period (0-3 d) was investigated. The increased cooling rate from 0.16 to 1.66°C/min led to a weakening of stability of the fried rice gel and an increase in the loss of moisture content of the fried rice from 0.86% to 7.11% after 3 d of refrigeration. The cooling rate of 0.78°C/min slowed the increase in hardness of fried rice and resulted in a lower short-range ordering (0.85) as well as the least increase in relative crystallinity (9.51%) after 3 d of refrigeration. However, a cooling rate of 1.66°C/min resulted in a crispy texture and the worst sensory quality of the fried rice after reheating. Both the 0.16°C/min and the 1.66°C/min cooling rates increased the viscosity and reduced the thermal stability of the fried rice paste system. In contrast, a cooling rate of 0.78°C/min is the most suitable cooling rate for refrigerated dry-steamed fried rice. These results will be of guiding significance for regulating the regrowth of dry-steamed fried rice by changing the cooling rate.