CROSS-FLOW MICROFILTRATION OF GUM-ARABIC SOLUTIONS - COMPARISON OF THE CLASSICAL SYSTEM WITH THE COCURRENT PERMEATE FLOW SYSTEM

Gum arabic is a natural gum exuded mainly by the trees Acacia senegal, currently used in the food industries for its emulsifying, thickening and stabilizing properties. Its present processing includes various o perations providing a quite turbid product. Crossflow microfiltration could be interesting for the clarification and the cold-pasteurization of the gum arabic solutions. Several experiments were therefore made with the crossflow microfiltration unit at ENSIA, using two different systems: the classical one (without permeate circulation), and the co- current permeate flow system (CCPF) allowing the exploration of the lo w transmembrane pressures range. With gum arabic solutions of 0.17 g s olids g(-1) solution and 70 degrees C, the best results after 60 min o f filtration (105.7 L h(-1) m(-2), 4.4% of solids retention and 83.4% of clarification) were obtained with the CCPF system at low transmembr ane pressure and high crossflow velocity (0.3 bar and 7.5 ms(-1)).