Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process[1] that involves freezing the product and lowering pressure, thereby removing the ice by sublimation.[2] This is in contrast to dehydration by most conventional methods that evaporate water using heat.[3]
Because of the low temperature used in processing,[1] the rehydrated product retains many of its original qualities. When solid objects like strawberries are freeze dried the original shape of the product is maintained.[4] 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). Primary applications of freeze drying include biological (e.g., bacteria and yeasts), biomedical (e.g., surgical transplants), food processing (e.g., coffee), and preservation.[1]
- ^ a b c Ratti, Cristina (2008-11-21). Advances in Food Dehydration. CRC Press. pp. 209–235. ISBN 9781420052534.
- ^ Fellows, P. (Peter) (2017). "Freeze drying and freeze concentration". Food processing technology : principles and practice (4th ed.). Kent: Woodhead Publishing/Elsevier Science. pp. 929–940. ISBN 978-0081005231. OCLC 960758611.
- ^ Prosapio, Valentina; Norton, Ian; De Marco, Iolanda (2017-12-01). "Optimization of freeze-drying using a Life Cycle Assessment approach: Strawberries' case study" (PDF). Journal of Cleaner Production. 168: 1171–1179. doi:10.1016/j.jclepro.2017.09.125. ISSN 0959-6526.
- ^ Ratti, C (2001). "Hot air and freeze-drying of high-value foods: a review". Journal of Food Engineering. 49 (4): 311–319. doi:10.1016/s0260-8774(00)00228-4.