Effect of moisture transfer on texture uniformity of cooked rice in electric rice cooker after heat preservation

• 1、School of Food Science and Technology, Jiangnan University, Wuxi 214122
• 2、Foshan Shunde Media Electric Appliance Manufacturing Co., Ltd, Foshan 528311

Abstract：The texture uniformity of rice cooked by electricrice cooker will deteriorate during the heat preservation process. In this paper, theuniformity of rice texture before and after heat preservationwas studied by means of physical property analyzer and low-field nuclear magnetic resonance technique. The water content, distribution and migration of rice before and after heat preservation were mainly investigated. The results showed that the middle-upper layer of rice was drier and harder after 24 hours of heat preservation in conventional mode, while the outer-upper layer of rice absorbed water, swelled or even broken. The difference of water content between the two parts was 6.55%, and the difference of hardness was 333.31 g. The relaxation signal showed that the binding force between constructional water of the two parts and the rice matrix became weaker after heat preservation.By adjusting the heat preservation mode by raising the temperature of the cover, the amount of condensed water on the rice cooker lid was reduced. Meanwhile the moisture content difference between the middle-upper layer and the outer-upper layer was reduced to 0.39% after 24 hours of heat preservation, and the hardness difference was reduced to 2.99 g. The binding force between constructional water of the two parts and the rice matrix was almost unchanged, and the texture uniformity of the whole pot rice after heat preservation was maintained.

Keywords： Rice preservation Texture uniformity Relaxation time Magnetic resonance imaging