【 Abstract 】 :

When heat is absorbed by water, it becomes steam; when heat is absorbed by ice, it becomes steam; the former is called evaporation; the latter is sublimation.Drying is evaporation and dehydration;Lyophilization is sublimation of dehydration.After the quick-freezing of water-bearing food, the moisture in the food can be sublimated away under the vacuum and proper heating conditions, so as to obtain the freeze-dried food.

When heat is absorbed by water, it becomes steam; when heat is absorbed by ice, it becomes steam; the former is called evaporation; the latter is sublimation.Drying is evaporation and dehydration;Lyophilization is sublimation of dehydration.After the quick-freezing of water-bearing food, the moisture in the food can be sublimated away under the vacuum and proper heating conditions, so as to obtain the freeze-dried food.