Changes in Physicochemical, Cooking and Sensory Characteristics of Rice Shifted from Low-temperature Storage

Abstract: The physicochemical, cooking, and sensory characteristics of stored rice were measured in order to investigate the quality changes in it after low-temperature storage. The quality of the stored rice was compared to that of the rice stored at ambient temperature (20 ℃, 30%–70% RH) at a 25 d interval during 200 d of storage. The rice was stored in a temperature controller at 4 ℃ for 3 months and later under a simulated condition similar to that of the main rice consumption areas in China (35 ℃, 80% RH and 30 ℃, 70% RH). The results showed that the fatty acid value, b value, and moisture content of rice stored at 35 ℃, 80% RH and 30 ℃, 70% RH had increased significantly, whereas its L value had decreased as compared to the rice stored at ambient temperature. Higher temperature storage caused a greater water uptake, whereas the dry mass in the residual cooking water notably reduced under the storage at 35 ℃ as compared to that at 20 ℃. Hardness increased and adhesiveness reduced under the storage at 35 ℃ as compared to that at 20 ℃. The shelf life of the stored rice which was shifted from a low temperature to three storage conditions used in this study was 75 d, 100 d and 150 d, respectively, in the main rice consumption areas of China.