In a previous study, the selective recovery of bioactive peptides especially an antihypertensive peptide identified as VW was evaluated from an alfalfa white protein hydrolysate using electrodialysis with ultrafiltration membranes (EDUF). The target antihypertensive peptide was recovered but with a maximum transmission rate of 1.67%. The purpose of this present study was to produce VW enriched fractions by controlling the pH of the recovery compartment and by scaling-up the EDUF technology with a semi-industrial pilot plant developing a total membrane area of 0.12 m(2). The maximum transmission rate recorded for the VW peptide was up to 32%. Furthermore, the process was studied in terms of ionic transport and ultrafiltration membrane fouling using the streaming potential measurements. It appeared that the combination AEM configuration/pH 3.0 would be more effective than the CEM configuration/pH 9.0; the highest peptide transport rate and final VW migration were obtained and the risk of fouling were minimized. (C) 2010 Elsevier B.V. All rights reserved.