this study, the effect of the different pectinase pretreat-ment conditions (enzyme concentration, incubation time andtemperature) on the viscosity of lemon juice was investigated.Lemon juice enzymatically treated under the optimal (enzymeconcentration 600 U/L, incubation time 45 min and incubationtemperature 30◦C) conditions has a turbidity of 800 NTU anda viscosity of 4.7 mPa s. The optimized treatment with pecti-nase followed by UF led to a clear and stable lemon juice witha reduction of more than 96% in viscosity and turbidity