Electrochemical modification of the redox potential of pasteurized milk and its evolution during storage

Several modifications that occur in milk during its processing and storage are driven by different oxidation-reduction reactions. In this study, a smooth electrolytic process was used to modify the redox state of the active species of milk thereby creating a mean to control these reactions. Five electroreduction treatments (2, 4, 6, 8, and 10 V) were applied to pasteurized skim milk. Parameters such as redox potential, dissolved oxygen, pH, conductivity, and current intensity were monitored during the course of each treatment. The proposed technology allows modulation of the redox potential of milk. Significant decreases of redox potential (441-707 mV) and of dissolved oxygen (3.3-8.3 mg L-1) were obtained. However, the results suggest that only a short-term modulation is created and that natural "milk equilibrium" is reestablished after 4-5 days of storage depending on the voltage difference applied during the electrochemical treatment.