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

Redox potential has applications in the food industry, especially to assess the microbiological and organoleptic qualities of milk. Therefore, electroreduction has also been put forward as a means of inhibiting and/or reducing oxidation phenomena in milk by modifying its redox potential. However, these investigations failed to isolate the components contributing to the value of redox potential of milk. In this study, a series of electrolysis treatments were carried out to determine how the different major components of milk as well as thermal treatment influence the redox potential during and after electroreduction. It was found that the fat and protein content of the milk products, together with the heat treatments applied, have a considerable effect on the redox potential of these milk products after electroreduction. Furthermore, this change in redox potential is only temporary, since the redox potential levels of electroreduced milk products return to positive values after only 4 days of storage. Industrial relevance: The redox potential of milk, widely studied in the past, gives some indications of the oxidative quality and stability of milk. This paper presents an innovative and clean method to control the redox potential of milk products with the use of electrochemistry. The results presented demonstrated the efficiency of electroreduction to reduce the redox potential and dissolved oxygen concentration of four milk products. © 2007 Elsevier Ltd. All rights reserved.