Comparing to the traditional hot air-flow drying, when the function of expelling humidity of the heat pump is used in the food drying, it has obvious virtues of saving energy, high product quality, and not influence by the whether, and so on; in addition, the environment of the heat pump drying is friendly and no exhaust gas.

Vacuum freeze-dried food with a bright future in the market;

The concepls of freeze-dry and the special characteristics of the freeze-dried food are detailed in this article.

At present,specilic charactcristics and tcchnological process for vacuum-freeze-dried foods are given,with a discussion of the broad prospects for developing the freeze-dried food industry as a focus.

The equipment selection for freeze-drying food factory;

Together with the two indices of the moisture content and the water activity,the application of the glass transition temperature in the process and storage of drying food was also explicated in detail.