Environmental Factors Which Cause Heat Damaged Rice Grain in Silo and Their Mechanisms

水稻籽粒是一种生物，在环境因子的作用下，会积极萌发和代谢。从物理上讲，散装谷物可以看作是一种热绝缘体。由单层钢板构成的圆筒形简易仓，在仓内储存的粮食起到隔热作用，近年来已得到推广。在正常的环境和气候条件下，如果不小心使用，很容易造成热损坏。热害大米是指因意外发酵而产生的大米。它有一种气味，像堆肥时，它仍然是湿的和新鲜的，不可食用。热害糙米外观颜色由深褐色变为深褐色，精米外观颜色由褐色变为粉红色，其热害机理是：（1）筒仓内热斑或湿斑的形成;这可能是由于雨水的泄漏，或在垃圾箱内侧的露水冷凝。冷凝发生在层内和体表面。(2)老鼠和昆虫等小动物 ...更多信息 成为热源。(3)微生物的生长在热点中及其周围扩散。(4)导热系数很低的粮食不会分散现场产生的热量。(4)这个地方变得更热更湿，导致谷物发芽。此外，霉菌等微生物的生长也会蔓延。(5)来自热点的热量和水分，以及生物的新陈代谢，造成筒仓内发酵破坏的恶性循环。(6)因此，热点导致在筒仓中发酵，其结果是，发酵或热损伤米将形成。一般来说，技术控制点已经多次公布。最重要的技能是控制温度和水（空气和谷物）。操作人员应通过观察粮食温度来控制存储系统，以发现热点的形成。如果发生这种情况，则应进行快速旋转。在寒冷地区和湿热地区都有发酵危害，但表现形式不同。少

Rice grain is a living thing which germinates and metabolizes actively if the environmental factors meet with. Physically speaking, bulk grain can be looked upon as a thermal insulator. Simple cylindrical bins composed by a single layer steel panel in which the stored grain acts as a thermal insulator have been popularized recently. These bins easily cause heat damaged rice grain if they were used carelessly under a normal circumstances and climates. Heat damaged rice is defined as the rice fermented by accidents. It has an odour like compost when it were still wet and fresh, and inedible. The external color of the heat damaged brown rice changed to dark brownish, and of milled rice, varies from brown to pink.The mechanisms causing heat damaged rice are ; (1) Formation of hot or wet spot in a silo. It may be by leakage of rain water, or condensation of dew at the inner side of the bin. Condensation occures in the layer and the surface of bulk. (2) Small animals as rats and insects can … More be heat sources. (3) Growth of microorganisms spreads in and surroundings of the hot spot. (4) Very low thermal conductivity of grain does not disperse the heat generated in the spot. (4) The spot becomes hotter and wetter causing the germination of the grain. Also the growth of microorganisms such as mold spreads. (5) Heat and water from the hot spots, and metabolism of living things cause a vicious cycle of in silo fermentatuion damage. (6) Thus the hot spots lead the fermentation in silo and as the results, fermentated or heat damaged rice will be formed.Generally speaking, the technical control points are already announced repeatedly. The most important skill is the control of temperature and water (of air and grain). Operator should control storage system by watching grain temperature to find the formation of hot spot . and if it occures, quick rotation should be applied. Pevention of water leakage and of rain drop are also important.Fermantation damage occures both in cold areas and in hot- humid areas, but in different styles. Less