Freeze drying

Freeze drying

Freeze drying, also known as lyophilization, is a process used to preserve perishable materials or make them more convenient for transportation. 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, bypassing the liquid phase. This results in the removal of water from the material while maintaining its structure and integrity.

The process typically begins by placing the material in a frozen state under vacuum. Heat is then applied, causing the frozen water to undergo sublimation. A condenser then collects the water vapor, leaving behind a dried product with little damage to its structure and biochemical properties.

Freeze drying is commonly used in the preservation of food, pharmaceuticals, biological samples, and other sensitive materials. It offers several advantages over other drying methods, including better retention of flavor, aroma, color, and nutrients, as well as a longer shelf life. Additionally, the lightweight and stability of freeze-dried products make them ideal for transportation and storage, particularly in situations where refrigeration is not readily available.