Water activity has been recognized as one of the most parameters in the prediction of food stability fora long time. G lass transition temperature is a threshold parameter of physical changes,it relates greatly to the storagesafety of food.

• 水分活度是建立在平衡态基础上的热力学概念，它曾长期被认为是预测食品贮藏安全性的最重要的指标之一玻璃化转变温度作为食品体系物理性质发生突变的临界参数，它是建立在动力控制过程的非平衡态基础上的概念，与食品贮藏安全性有密切的关系。