The eating quality of rice is the sensory characteristics of rice after cooking, and rice with high eating quality is often favored by consumers. Soaking is a necessary step before the rice is cooked. During the soaking process, the water absorption of rice will greatly affect the final eating quality of cooked rice, but the key factors affecting the water absorption of rice and its process mechanism are not clear. In this study, rice with different eating qualities was used as a material to explore the morphological changes and proton distribution during rice soaking. The outer layer of low eating quality rice had a higher protein content. During the soaking process, the high protein content in the outer layer may inhibit the entry of water into the rice, resulting in a decrease in water absorption and proton mobility. The results of scanning electron microscopy showed that moisture entered the inner layer of rice from the outer layer of rice by cracks, and the cracks disappeared after the soaking was completed. Compared to the high eating quality rice, the water was inhibited in entering the low eating quality rice.
