![]() ![]() In the 1950s–1960s, freeze drying began to be viewed as a multi-purpose tool for both pharmaceuticals and food processing. The freeze-drying process was developed as a commercial technique that enabled blood plasma and penicillin to be rendered chemically stable and viable without refrigeration. Because of the lack of refrigerated transport, many serum supplies spoiled before reaching their recipients. Ī significant turning point for freeze drying occurred during World War II when blood plasma and penicillin were needed to treat the wounded in the field. No further freeze drying information was documented until Tival in 1927 and Elser in 1934 had patented freeze drying systems with improvements to freezing and condenser steps. Shackell independently created the vacuum chamber by using an electrical pump. Modern freeze drying began as early as 1890 by Richard Altmann who devised a method to freeze dry tissues (either plant or animal), but went virtually unnoticed until the 1930s. The process involved multiple cycles of exposing potatoes to below freezing temperatures on mountain peaks in the Andes during the evening, and squeezing water out and drying them in the sunlight during the day. The Inca were freeze drying potatoes into chuño from the 13th century. ![]() Primary applications of freeze drying include biological (e.g., bacteria and yeasts), biomedical (e.g., surgical transplants), food processing (e.g., coffee) and preservation. ![]() If the product to be dried is a liquid, as often seen in pharmaceutical applications, the properties of the final product are optimized by the combination of excipients (i.e., inactive ingredients). When solid objects like strawberries are freeze dried the original shape of the product is maintained. īecause of the low temperature used in processing, the rehydrated product retains much of its original qualities. This is in contrast to dehydration by most conventional methods that evaporate water using heat. Freeze-dried ice creamįreeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product and lowering pressure, removing the ice by sublimation. For the Batman episode, see Instant Freeze. ![]()
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