Ultrafiltration of Clementine mandarin juice by hollow fibre membranes

Modified poly(ether ether ketone) (PEEKWC) and polysulphone (PSU) hollow fibre (HF) membranes were prepared via dry-wet spinning technique through the phase inversion process and characterised by pure water permeability, dextran rejection and scanning electron microscopy (SEM). The performance of the membranes, in terms of permeate flux an quality of permeate, was studied for clarification of Clementine mandarin juice. Experiments were performed in selected operating conditions according to the batch concentration procedure up to a final volume reduction factor (VRF) of 2. The permeate flux profile observed with the PSU membranes was lower than that observed with the PEEKWC membranes. Almost all total soluble solids and citric acid of the original juice were recovered in the permeate. The resulting juice after filtration showed a complete removal of suspended solids with a consequent improvement of colour and clarity. PEEKWC membranes showed a lower rejection towards antioxidant compounds (21.8%) in comparison with the PSU membranes (32.0%).