Rehydration capacity is the ability of a dried food product to reabsorb water and recover its original texture and volume when soaked, and is a key quality indicator for dried vegetables, mushrooms and fruit used in cooking and food manufacturing.
In trade practice
Buyers of dried mushrooms, vegetables and fruit for food manufacturing specify a minimum rehydration ratio, expressed as the weight of rehydrated product relative to dry weight after a defined soaking time and temperature. Freeze-dried products typically achieve higher rehydration ratios than hot-air-dried equivalents because the sublimation process preserves cellular structure. Suppliers should provide test data from the actual drying run, as rehydration performance varies with inlet temperature, slice thickness and raw material maturity. A common specification error is quoting a ratio measured under laboratory conditions that differ from the buyer’s intended processing method.
In a specification
A specification states the minimum rehydration ratio as a numeric value (indicative), the soaking medium (water or broth), temperature and duration used for measurement, and the test method or internal protocol reference.