Effects of Different Drying Methods on Rice Quality Before and After Soaking

Abstract

In order to explore the effects of different rice drying methods on physicochemical properties and taste quality of rice before and after soaking, the same variety of japonica rice after natural drying and hot air drying was used as the main raw material to explore the effects of different rice drying methods on water content, water distribution, microstructure, crystal structure, gelatinization characteristics, iodine blue value, taste value and texture characteristics of rice before and after soaking. The results showed that there were more cracks in the hot-air drying group, and the relative crystallinity, recovery value and gelatinization temperature were significantly lower than those in the natural drying group (P<0.05), while the disintegration value, final viscosity, rice viscoelasticity and taste value were significantly higher than those in the natural drying group (P<0.05). The water absorption rate of rice in the hot-air drying group was significantly higher than that in the natural drying group (P<0.05) at the beginning of soaking, and the water content of rice in the two groups basically reached saturation after soaking for 30 min. After soaking, the number and width of cracks in the two groups increased significantly. The relative crystallinity and gelatinization temperature decreased by 1.03%~1.98% and 2.45~3.40 ℃, respectively. The peak viscosity, valley viscosity, disintegration value, final viscosity, recovery value and viscoelasticity of rice were significantly increased (P<0.05), the iodine blue value was increased by 15.60%~21.26%, and the taste value of rice was increased to 84.73~85.46.

Keywords

• drying method
• rice
• soaking
• moisture distribution
• taste quality