Freeze Drying is a process in which ice is evaporated from a frozen product without any melting taking place. This process (called sublimation) takes place at a very low temperature and pressure leaving behind a high-quality product. The goal of freeze drying is to produce a substance with good shelf stability which is unchanged after reconstitution with water, although this depends also very much on packaging and conditions of storage.
The advantages of freeze drying can be summarized as follows:
- The drying at low temperature reduces regradation of heat-sensitive products. The freeze dried product retains most of the aroma, flavor, vitamins and nutritional values of the fresh product.
- The freeze dried product preserves the original colour and shape.
- The moisture content of the final product can be controlled during the process. The freeze dried product has a long shelf life due to low residual moisture.
- Usually more than 90% of the original product is water, so in its new form the freeze dried product becomes very light and much easier to ship.