Studying the redox state of wines under oxidative processes with a multi-parametric analysis

Abstract

Wine oxidation phenomena are becoming a strong issue in the context of climate change. The detection of wine reducing compounds such as phenolic acids, tannins, thiols, etc. is thus essential to better understand the antioxidant capacity, ageing behaviour and premature oxidation of wines. Conventional spectrophotometric methods (ABTS, DPPH) are widely used as reference methods, but they suffer from significant limitations due to their lack of selectivity and interference from other reducing compounds naturally present in wine matrices.1 In this context, electrochemical approaches offer major advantages, as they are rapid, easy to implement and highly selective towards redox-active reducing species. The research conducted within the RedoxWine joint laboratory (CBMN – Biolaffort) primarily focuses on the development of electrochemical analytical protocols to monitor key redox-active molecules in all types of wines allowing to define in real-time their redox signature.2 In this study, the proposed methodologies are applied to the monitoring of oxidative processes in white wines. Several electrochemical sensors are developed to investigate the relationships between reducing species, including sulfites, flavonoids, polyphenols, and oxidizing agents – dissolved oxygen, free metals and reactive oxygen species (H₂O₂, O₂•^–) – generated or introduced under controlled conditions. The evolution of the wine redox chemistry during oxidation is finally assessed through a combination of electrochemical and spectroscopic measurements, including redox signatures, sulfite content, dissolved oxygen, pH, color parameters (CIELab) and thiol concentrations.

References

1. Lopez-Vélez, M., Martinez-Martinez, F., Del Valle-Ribes, C., (2003). The Study of Phenolic Compounds as Natural Antioxidants in Wine Crit. Rev. Food Sci., 43 (2), 233–244.
2. Dauphin, A.L., Guilbault,S., Arbault, S., (2026). Deciphering the redox signature and reactivity of wines with differential pulse voltammetry, Bioelectrochem., in press.