Description
Vacuum‑freeze dehydration removes water from food by sublimation under reduced pressure, preserving heat‑sensitive compounds and cellular structure.
Technical
The process begins with pre‑freezing the food at sub‑zero temperatures, typically between –40 °C and –80 °C. Under a vacuum of 0.01–0.1 mbar, ice transitions directly to vapor, a phase change that conserves nutrients and texture. The rate of sublimation is governed by the vapor‑pressure differential between the ice surface and the chamber, and the process is completed over 24–72 h depending on thickness and moisture content.
Science
Primary Reaction
Sublimation of ice to vapor under vacuum
Sensory Profile
Aroma ()
drysweetnuttysubtlemildearthy
Origin & History
Civilization
U.S. military