The Effect of Electrode Material on the Measured Redox Potential of Red and White Wines

Abstract

Redox potentials in wine were observed to be lower at platinum than at gold electrodes, while higher values were seen at glassy carbon. These differences are explained in terms of mixed potentials involving principally ethanol oxidation coupled to H+ and O2 reduction, while other electroactive species are also expected to contribute. The redox potentials of a range of red and white wines were similar, suggesting that phenolic antioxidants are not sufficiently electroactive to markedly affect the measured potential. The redox potential still provides a useful measure for characterizing conditions under which phenolic antioxidants are stable against oxidative degradation.