Direct current electroosmosis dewatering of tomato paste suspension

Removal of water from food suspensions is of great interest in food technology. Among these suspensions is tomato paste. Direct current electroosmosis dewatering technique was used to concentrate tomato paste suspension. The apparatus was designed for this objective. The tomato paste suspension was prepared at a certain concentration, held between two electrodes in a vertical mode and direct electrical field (DC) applied to the suspension bed. The effects of voltage, current, bed height, pH and initial solid concentration were examined, in terms of water flux per unit charge and energy of dewatering. Significant amounts of water were removed by electroosmosis dewatering process under the operating conditions of the experiments used in this work. The process saved 70% of energy compared with that necessary to vaporize the same amount of water.