Lüofilisatsioon

Lüofilisatsioon, also known as freeze-drying, is a dehydration process commonly used to preserve perishable materials or make them more convenient for transport. It involves freezing the material and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase. This is achieved by initially freezing the material, then reducing the pressure to a point where ice can transition directly to water vapor. Finally, a higher heat source is applied to vaporize any remaining water.

The process typically involves three main stages: freezing, primary drying (sublimation), and secondary drying (desorption). In the freezing stage, the material is cooled to a temperature below its freezing point. Primary drying involves lowering the pressure and applying gentle heat, causing the ice to sublimate. Secondary drying removes any residual unfrozen water molecules through desorption at slightly higher temperatures and pressures.

Lüofilisatsioon is advantageous because it minimizes damage to the material's structure and preserves its biological activity, taste, aroma, and color. This makes it ideal for applications such as pharmaceuticals, food preservation (e.g., instant coffee, dried fruits), and the production of biological samples for research. The resulting product is lightweight, has a long shelf life, and can be easily reconstituted by adding water.