Vast amounts of liquid food are industrially concentrated in order to reduc
e storage, packaging, handling and transportation costs. Vacuum evaporation
is the predominant method used by the food industry to produce liquid food
concentrates, despite serious drawbacks (poor product quality, high energy
demand). This paper describes the research efforts to develop alternative
techniques that could be applied on an industrial scale to overcome the dis
advantages of currently used concentration methods. A major part of these a
ttempts is focused on the application of osmotic membrane techniques, namel
y direct osmosis, membrane distillation and osmotic distillation. (C) 2001
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