玉米应力裂纹的研究进展

Review of Study on Stress Cracking in Maize During Drying Process

应力裂红是谷物干燥过程中品质损伤的主要形式之一．带有应力裂纹的玉米机械强度降低，容易破碎，降低了谷物等级．产生应力裂纹的主要原因是籽粒内部湿热应力大于胚乳的抗破裂极限。影响玉米应力裂纹率的主要因素有热空气温度和相对湿度、谷物的初始和终了含水率、冷却速度及干燥机型等．应力裂纹的生成机理、预测和控制技术有待于进一步的研究．通过改进干燥工艺，可以减轻或避免玉米应力裂纹发生，提高玉米的等级．

Stress cracking in maize is one of the maine form of quality damage during drying. Whenhandle and transporte,the kernels with stress cracks break more readily than sound kernels leading toconsiderable amounts of brokens and fines. Main reason of forming stress cracks is that temperatureand moisture stress are more than yield stress in maize. Asides grain variety,initial and final moisturecontent affect percentage of stress crack,drying,tempering and cooling condition and dryer-type alsoaffect the extent of kernel damage. It needs advanced study on stress crack forming mechanism,prediction and domination. Though improving drying technique, the stress crack of the maize can bedecreased or eliminated.