Description
Freeze‑drying removes water from food by sublimation under vacuum at sub‑zero temperatures.
Technical
The process involves primary drying (sublimation) at low pressure (0.1–1 kPa) and sub‑zero temperatures (–20 °C to –40 °C), followed by secondary drying at 20–40 °C for 4–24 h to remove bound water. This preserves cellular structure, nutrients, and sensory attributes while preventing enzymatic and microbial degradation.
Science
Primary Reaction
Sublimation of ice to water vapor
Sensory Profile
Aroma ()
drycrispsubtle fruitpreservedearthymildly floralnutty
Origin & History
Civilization
Japanese
Era