Effect of flow rate and acid molarity on redox potential modulation during electroreduction of milk and simulated milk aqueous mineral phase

Electroreduction of milk is an efficient process to decrease the ORP of milk. However, the changes induced in milk are reversible and fouling is formed at the membrane surface. Results obtained showed that ORP reduction was more important when a flow rate of 300 ml/min was used in comparison with a flow rate of 100 ml/min. Moreover, at the higher flow rate, less fouling was observed on the membrane surface than at 100 ml/min. However, it appeared from the calculation of mass equivalent migrated that parameters studied (flow rate and acid concentration) did not have a direct influence on the electroreduction process but on the system resistance. This study is the first to our knowledge to show that in storage conditions where the gaseous exchanges and especially the oxygen are limited, it is possible to maintain during seven days a negative ORP in electroreduced milk.