Effects Of Different Operating Condition On Vacuum Freeze-Drying Of Foodstuffs

With freeze-drying foodstuff coming to market largely, the technique on vacuum freeze-drying has made progress rapidly. In this thesis, a number of experimental studies had been performed with familiar material in the market, like carrot, potato and ginger. The experiment also measured some material characteristics, such as eutectic point, melting point and rehydration rate and completely analyzed the mechanism of freeze-drying and discussed freezing parameter that affected freeze-drying process, such as the thickness, temperature, original containing-water rate of material, pressure of drying chamber, freezing and heating mode. Through the mutifactor experimental studies, we had a conclusion that the most important parameter that had affected freeze-drying process was material thickness, heating temperature and pressure of chamber. Last, the mathematical model on vacuum freeze-drying was established and solved with computer.