In this study,four types of commercially available polymeric membranes (Table 1) were applied for Apple and beet juice concentration using the OMD process.The used membranes were charecterized by different pore sizes (0.10,0.20,and 0.45) as well as were made of different materials (PTFE,PVDF,and PP). Membranes made of these materials were chosen according to their hydrophobic character,required in the OMD process. The membrane active area was equal to 1.20