EFFECT OF ULTRAFILTRATION ON CONCENTRATED APPLE JUICE COLOR AND TURBIDITY

Colour and turbidity of conventional bentonite-gelatin clarified apple juice was compared with 30,000-50,000 and 100,000DA hollow fibre ultr afiltered apple juice, with and without pectinolytic enzyme treatment. Results indicated that objective quality of ultrafiltered apple juice compared favourably with conventionally clarified apple juice over 30 weeks of storage at 37.5 degrees C. However, treatment with pectinoly tic enzymes before ultrafiltration increased both the initial colour a nd the browning rate. No significant differences were found in the val ues of the transmission haze after storage.