ABSTRACT
The use of osmosis allows both ways of decreasing
water activity in food to be applied simultaneously.
The permeability of plant tissue is low to sugars and
high molecular weight compounds; hence, the mater-
ial is impregnated with the osmoactive substance in
the surface layers only. Water, on the other hand, is
removed by osmosis and the cell sap is concentrated
without a phase transition of the solvent. This makes
the process favorable from the energetic point of
view. The flux of water is much larger than the coun-
tercurrent flux of osmoactive substance. For this
reason the process is called osmotic dehydration or
osmotic dewatering.
