The working principle of a food freeze-drying machine is to freeze food at low temperatures, and then use the sublimation phenomenon in a vacuum environment to directly convert solid ice in the food into water vapor and remove it, thereby achieving the purpose of drying. During this process, the temperature of the food is kept below freezing point, effectively preventing the oxidation and degradation of nutrients.

Specifically, food dryers have multiple advantages. Firstly, it is convenient and fast, as it can dry a large amount of fruits, vegetables, and other foods in a short period of time, making it very convenient to store. Secondly, during the drying process, the moisture in the food evaporates, but other nutrients are retained and become more concentrated due to the lack of moisture. In addition, using a food dryer can save a lot of labor and time, making it more efficient than traditional drying and display.