Electrochemical triggering of the Chardonnay wine metabolome

Abstract

Oxidation of wine upon bottle ageing is a crucial matter of concern for the qualitative long-term storage of white wines. However, understanding the various molecular mechanisms potentially involved, which can impact the wine composition, requires that top-down analytical strategies are implemented. Here, we report the analysis of bottle aged Chardonnay wines made from the same must, but differing by the amount of SO2 initially added to the must at pressing (0 and 8 g·h L−1). Metabolomics fingerprints obtained from electrochemical simulation of oxidative reactions were obtained by coupling of either on-line or off-line electrochemical oxidation to FT-ICR-MS detection. We reveal that, whatever the electrochemical DC voltage is, wines with initial SO2 addition displayed molecular fingerprints, which remained more similar to the non-oxidized wine without initial SO2 addition. We further show that a diversity of sulfur-containing compounds appeared to be the most sensitive to oxidation, whereas nitrogen-containing compounds were mostly formed.