ANALYSIS OF THE AFFECTING FACTORS OF FOOD FREEZE-DRYING PROCESS

The freeze drying process of an apple was researched, and the factors of influencing the freeze drying process were analyzed: The temperature decreasing rate was faster, the longer of the freeze drying time, the quality of the freeze dried food was good. Keeping higher vacuum of the freeze drying room not only could cut down the freeze drying time, but also could improve the quality of freeze dried food, so the suitable temperature of heating plate should be selected. Decreasing the temperature of condenser could shorten freeze drying time and improve the quality of freeze dried food, but when the condenser temperature was too lowest the above mentioned effect was not obvious.