Influence of wine-relevant metal ions on oxygen consumption kinetics and tannin-related responses in an H₂O₂-mediated accelerated model wine system.

This study evaluated how common wine-relevant metal ions influence oxygen consumption behavior and soluble tannin-related responses in an H₂O₂-mediated accelerated model wine system. The presence of Fe3+, Cu2+, Ca2+, Al3+, and Co2+ markedly altered oxygen consumption kinetics, which could be described using a power-function model with parameters dependent on metal ion identity and concentration. Electronic tongue measurements showed that metal ions affected instrumental astringency-related responses, while the individual contributions of metal ion properties, H₂O₂-mediated reactions, tannin-related transformations, and potential metal-tannin interactions could not be distinguished under the present experimental conditions. Chemical analyses further revealed concentration-dependent changes in the soluble tannin fraction, including variations in tannin concentration, subunit composition, and mean degree of polymerization after centrifugation. Overall, these results provide comparative empirical evidence that wine-relevant metal ions can modify oxygen consumption behavior and soluble tannin-related parameters under the defined H₂O₂-mediated accelerated model wine conditions.