The performance of zirconium oxide (15 kDa, 50 kDa) membranes was studied for clarification of apple juice by crossflow ultrafiltration. The results showed that membrane fouling was low at high feed velocity (7 m/s) and low transmembrane pressure (150 kPa). The juice permeation at optimal conditions (400 kPa and 2 m/s) was about 60 m(3)/(m(2.)kWh); however, this level was 35% less then could be expected due to severe fouling. Ultrafiltered apple juice had excellent quality attributes that fulfil commercial specifications.