The effect of fouling upon the performance of synthetic membranes used to fractionate gum arabic

The fractionation of 2 wt% gum arabic using 0.1 μm polysulfone flat sheet membranes is described. Fluxes of between ~50 and 75 L m-2 h-1 were achieved during diafiltration experiments at cross-flow velocities of between 0.97 and 1.63 m s-1. Although high solids rejection is seen by the membrane, a high degree of fractionation is also seen, which establishes the principle of this novel membrane application. Rejection of high MW arabinogalactan-protein complex (AGP) is seen with selective transmission of lower MW glycoprotein (GP). Multi-cycle experiments show that flux can be recovered to a high degree after cleaning of the membrane, although some decline is seen after 5 cycles.