freeze-dried
Meaning of freeze-dried: Freeze-dried describes a substance preserved by freezing it and then removing its moisture through vacuum drying.
Definition of freeze-dried
Freeze-dried describes a substance, such as food, a biological specimen, or certain medications, that has been preserved through a process called lyophilization. The substance is first frozen solid, and then placed under vacuum conditions that cause the frozen water within it to pass directly from ice into vapor without passing through a liquid phase, a process called sublimation.
Because the moisture is removed at low temperature rather than through heating, freeze-drying tends to preserve the structure, flavor, and chemical activity of the original material better than drying methods that use heat. This makes the technique useful for preserving substances that would otherwise be damaged or degraded by warmth.
Freeze-dried products are typically lightweight, shelf stable for extended periods, and can often be restored close to their original form by adding water back before use, which is why the technique is used for everything from packaged food to certain laboratory and pharmaceutical preparations.
Also known as
Used in a sentence
The vaccine was supplied in freeze-dried form and reconstituted with sterile water before administration.
Good to know
Freeze-drying removes moisture without heat, distinguishing it from conventional dehydration, which can degrade heat sensitive proteins and other active components that freeze-drying is better able to preserve.