Optimization of cranberry juice deacidification by electrodialysis with bipolar membrane: Impact of pulsed electric field conditions

Cranberry is well recognized for its beneficial effects on human health, but consumption of cranberry juice is limited due to its high acidity (high organic acid content) which is the cause of undesirable side effects such as diarrhea, vomiting and bloating. Therefore, the acidity could be reduced to improve the palatability of the juice and to decrease these side effects. Deacidification of juices by conventional electrodialysis and by electrodialysis with bipolar membranes (EDBM) using direct current (DC) has been shown to be very effective in comparison with chemical methods, such as calcium salt precipitation or ion-exchange resin. Therefore, the aim of this study was to evaluate the impact of applying a pulsed electric field (PEF) during EDBM on cranberry juice deacidification and electrodialytic parameters. The PEF procedure consists of introducing an electric pulse and a pause consecutively for a given time. PEF has numerous advantages such as reducing fouling and increasing current efficiency. Nine different pulse/pause combinations were tested: 1 s/0.1 s, 1 s/1 s, 2 s/2 s, 6 s/0.1 s, 6 s/1 s, 6 s/2 s, 10 s/0.1 s, 10 s/1 s, and 10 s/2 s. Cranberry juice was deacidified about 15-18% faster using PEFs and the energy consumption decreased by 7-10% for 1 s/1 s and 2 s/2 s conditions in comparison to DC conditions. In both PEF conditions, the migration of citric and malic acid anions was faster, thus leading to an increased rate of deacidification. To the best of our knowledge, this is the first demonstration of the efficiency of using PEF for the deacidification of fruit juice. EDBM under PEF would be a green and sustainable alternative process for deacidifying fruit juice and preserving its organoleptic characteristics.