Freeze drying or lyophilization is a low temperature dehydration process. Typically use to preserve perishable materials or make the material more convenient for storage.
Freeze drying removes water by freezing the materials, and then place them in a vacuum chamber, to enable the frozen water in materials to sublime directly from solid phase to gas.
There are mainly 3 stages in a freeze drying process: Freezing, Primary drying and Secondary drying.
Fruit, pharmaceuticals, cosmetics, vegetables, vaccines, probiotics, yogurt etc.