Abstract:

【Objective】 Microstructure difference of rice between ventral side and dorsal side was researched, and the mechanical property difference with three-point breaking force between ventral side and dorsal side were also researched. Correlation between mechanical property and microstructure of rice was established, thus providing a theoretical basis for rice fissure appearance from dorsal side of rice grain. 【Method】 Ventral and dorsal side of two rice varieties at starch granule, cell and aleurone stratum levels were investigated under scanning electron microscope. Mechanical property of rice was tested by three-point breaking force. 【Result】 The microstructure of rice on ventral and dorsal side is different at starch granule, cell and aleurone stratum levels. Microstructure difference of rice on ventral and dorsal side affects structure strength and mechanical properties of rice between ventral and dorsal side. And the structure strength in ventral side is lower than that in dorsal side. These accord with mechanical property. Fracture form in microstructure is also different on ventral and dorsal side. 【Conclusion】 Rice fissure that started from the ventral side is related with structure strength of ventral side will be lower than that of dorsal side under desorption and absorption condition.

Key words: rice, ventral side, dorsal side, microstructure, mechanical properties, fissure