Freeze DryingFreeze drying is a more common term for a scientific process called lyophilization. Freeze drying is a process used to preserve material. Freeze drying is essentially a dehydration process, which is used both to preserve and to make material lighter for transportation. Freeze drying works by freezing materials to a relatively low temperature (typically below -50 degrees centigrade). What makes freeze drying different from normal preservation is the subsequent exposure of the materials to a very low pressure, which allows the water frozen during freeze drying to sublimate away from the material and collect as ice in the ambient atmosphere, which greatly reduces the amount of water in the material. Because freeze drying involves removing water, it retards the activity of micro-organisms in a material that would normally contribute toward decay. Materials that have been subject to freeze drying are often sealed so that the water removed during freeze drying cannot be reabsorbed. Once a material subject to freeze drying has been sealed, it can normally be stored at room temperature. Freeze drying is often used to preserve food, because freeze drying tends to damage matter less than some other freezing processes, and so texture and taste are often better where freeze drying has been used. Because freeze drying makes food lighter, it is often used where weight is important. Astronauts use food that has been subject to freeze drying, and hikers also benefit from food that has been subject to freeze drying. A less well known use for freeze drying is the manufacture of instant coffee, which is a very strong coffee solution which has been subjected to freeze drying and then crushed to powder. Ice cream is also a popular subject for freeze drying. Freeze drying can also happen naturally. Freeze drying is the process that has happened when a mummified body is found in a very cold place at a high altitude. LSL | Search Engine Optimisation
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