Freeze Drying

Freeze drying, also called lyophilization, is a dehydration process that freezes a material and then removes the ice by sublimation under vacuum, leaving a dried product that can often be rehydrated later with little loss of structure or activity. French physiologists Jacques-Arsene d'Arsonval and Georges Bordas built an early freeze-drying apparatus in 1906 at the College de France to preserve biological specimens and serum. The technique was substantially advanced during the Second World War, when American bacteriologist Earl W. Flosdorf helped develop practical industrial freeze-drying equipment to preserve blood plasma for military use, laying the groundwork for its later widespread industrial and pharmaceutical application.