What is Freeze Drying and how it works
Freeze drying (sublimation, lyophilization) is a low temperature dehydration process that involves freezing the product, releasing the pressure, and then removing the ice by freeze drying (or liofilisation, sublimation). Unlike dehydration using most traditional methods, in which water is evaporated using heat, the lyophilized product is of excellent quality, its original vitamins, proteins, other beneficial substances and the shape of the product are preserved as if it were the original product.
During the process, the material is cooled and vacuummised below its triple state point (e.g. for water it is 0 deg. C and 6/1000 of atmosphere pressure) – the point where solid, liquid and gas phases of the material can coexist. The freeze drying processe should pass at lower than triple point temperature and pressure. The lower temperature and pressure are – the better product processsing quality will be, but the longer processing time. To find the “golden middle” is the masterpiece state of freeze drying technology.