OE, also called osmotic distillation (OD), is a process based on the use of a
porous hydrophobic membrane to separate two liquid phases (most commonly aqueous
solutions) that differ greatly in terms of solute concentrations (Hogan et al., 1998;
13
Kunz et al., 1996; Vaillant et al., 2001a). It is a relatively new technology for
concentration of liquid foods such as fruit and vegetable juices and various non-food
aqueous solutions such as pharmaceutical products.