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The main objective of this work was formulating adequate membranes and determinate the optimal operating conditions for orange juice clarification in order to obtain a reasonable amount of permeate flux and preserve its organoleptics characteristic. The MF/UFmembranes were prepared by inversion phase technique. Casting solution consisted of PVDF, PMMA and PVP in dimethylformamide solvent (DMF). The nascent membrane was immersed in bidistillated water coagulation bath and then transferred to fresh water for 24 h. The permeation experiments were carried out in a cross flow test cell with an effective membrane area A=6.9 x 10-3 m2. The membrane hydraulic permeability was calculated from Darcy s law, measuring the permeate amount of pure water as a function oftransmembrane pressure. The distribution ofpore radius was measured by air-liquid displacement method. The orange juice was obtained from pressing of the fresh fruits in a squeezing machine and then kept in a freezing chamber at - 18°C. In the experimental permeation test the feed juice solution was pumped continuously through the microfiltration unit by means of a peristaltic pump at a predetermined cross flow velocity, v, and transmembrane pressure, p. Each test was carried out in a closed circuit for approximately 70 min, and it was performed with total recycling. The operating pressure was between 0.4 bars and 1 bar and the cross flow velocity ranged from 0.77 mis to 1.25 mis. For all the runs the permeate flux decrease during the first several minutes of operation and then it becomes constant for the remainder microfiltration operation (steady state). The main factors that contribute to the flux decay are the concentratio polarization, adsorption and development of a gel-layer at the membrane surface. The results show that an increase in p do not alter the permeate characteristics. The best clarification performance was obtained at v= 1.25 m