Description
Freeze‑drying and spray‑drying are the two most widely used thermal dehydration methods for preserving food quality and extending shelf life.
Technical
Freeze‑drying removes water by sublimation under low pressure (≈100–200 mbar) at temperatures between ‑40 °C and 0 °C, preserving heat‑sensitive nutrients and volatile aromas. Spray‑drying atomizes a liquid feed into a hot air stream (inlet 150–250 °C, outlet 80–120 °C) achieving rapid evaporation (<1 s) and producing low‑moisture powders, but can induce Maillard browning and oxidation if not carefully controlled.
Science
Primary Reaction
Sublimation (freeze‑drying) and rapid evaporation (spray‑drying)
Sensory Profile
Aroma ()
crispfruityneutraltoastedcaramelized
Origin & History
Civilization
Military and industrial food sectors
Era