This work is devoted to ultrafiltration of sugar beet juices obtained by conventional high temperature diffusion and novel pulsed electric field (PEF) assisted low temperature diffusion. Filtration experiments were carried out in the concentration mode (up to the final volume concentration factor 7.5) using a batch dead-end filtration cell and hydrophilic polyethersulfone membranes with nominal molecular weight cut-offs (MWCO) of 10, 30 and 100 kDa. Two types of filtration experiments were carried out: without stirring and under constant stirring of feed juice. The transmembrane pressure was within the range 0.5-3.7 bar. The influence of filtration conditions (transmembrane pressure, membrane MWCO and stirring) on filtration rate, filtration mechanism and filtrate quality (purity and coloration) were studied and the results for juices obtained by conventional diffusion and by PEF-assisted diffusion were compared. (C) 2011 Elsevier B.V. All rights reserved.