Water activity (definition) 水分活度a的定义 a w is the ratio of water vapour pressure of food(p)to that of pure water(p)at the same temperature. w指相同温度下，食品的水蒸汽压P和纯水的蒸 汽压P0之比。 aw=plpo 0<aw<1 9 窗 19 a w is the ratio of water vapour pressure of food (p) to that of pure water (po ) at the same temperature. a w指相同温度下，食品的水蒸汽压P和纯水的蒸 汽压P0之比。 a w = p/ po 0 < a w < 1 Water activity (definition) 水分活度a w的定义