Crossflow microfiltration (MF) and ultrafiltration (UF) experiments of limed mixed juice to pH of 7.5 were carried out in plate and frame module employing polysulphone membranes. The experimental study was carried out to examine the effects of membrane molecular weight (MWCO) and the transmembrane pressure (TMP) on the membrane fouling characteristics and flux decline behavior. A comparative analysis using one MF membrane (GRM0.1PP MF) and one UF membrane (GR40PP UF) was done at different TMP (viz. 1.0, 1.5 and 2.0 bar). Three theoretical models (viz. cake filtration model, internal pore blocking model, and complete pore blocking model) were used to predict the membrane resistances and permeate flux. The models were used further to help in the analysis and to isolate a suitable membrane among the studied one with respect to flux and resistance. It was noticed that in all cases the membrane fouling was the highest at the first period of operation. Study of the mechanisms responsible for flux decline in MF and UF of limed mixed juice suggested that the membrane fouling is in good correlation with the cake filtration model and the pore narrowing (internal pore blocking) model for both the GRM0.1PP MF and GR40PP UF.