Fouling-resistant Na-ZSM-5 zeolite membrane for fruit juice concentration in forward osmosis process

To evaluate the potential of Na-ZSM-5 membrane for liquid food concentration, the concentration of fruit juice by a tubular Na-ZSM-5 membrane was demonstrated in forward osmosis operation. Apple, orange, and pineapple juices were successfully concentrated, maintaining their quality without contamination by a draw solution based on a molecular sieving effect of the zeolite membrane. For example, the sugar content of apple juice increased from 10.7 to 17.1 o Brix after 24 h of dehydration. The fouling resistance of Na-ZSM-5 membrane was evaluated using a 10 g L-1 pectin solution and cellulose suspension. Na-ZSM-5 membrane showed stable dehydration performance for fruit juice concentration over 120 h without fouling due to pectin or cellulose. In addition, the membrane exhibited high heat resistance, with no deterioration up to 353 K. We showed that Na-ZSM-5 membrane is a potential material for fruit juice concentration because of its superior heat, acidity, and fouling resistances.