Lyophilization (freeze dry) is the technique of protection through a process called sublimation for drying the material.
Water contained in the products is frozen at the very beginning and while in this situation, the water is expelled by sublimation.
Sublimation is the transition of the material from solid (ice) state to gas (water vapor) state, by skipping the liquid state of the material, that is, without allowing the ice to melt. The iced water directly evaporates in low-pressure environment, in the event of a slight increase in temperature. In this way, high temperatures are not needed for obtaining preservation.
Thus, it does not cause changes like cleavages and so on in products’ molecule and cell structure. Their inner and outer structures are not spoiled, they preserve almost their original states.
Areas of uses of lyophilization
- Chemistry and biochemistry
- Food Industries
- Less common practices
- Books damaged by water
- Documents and manuscripts
- Animal by-products
- Dairy products yeasts
- Preservation of various archaeological excavation outputs
- Museum exhibition objects such as plants and animals