We tried to give a part of the answer to this question by monitoring glutathione during winemaking and storage. The novelty of our approach is to quantify simultaneously the three known forms of glutathione: free glutathione (GSH), oxidized form (GSSG) and glutathione-S-sulfonate (GSSO3H).
SO2 reaction with electrophilic species present in wine, including in particular carbonyl compounds, is responsible for the reduction of its protective effect during wine aging. In the present study, direct 1H NMR profiling was used to monitor the reactivity of SO2 with acetaldehyde under wine-like oxidation conditions.
Since the 18th century, sulfur dioxide (SO2) is used in winemaking. Added at different steps, its antimicrobial but also antioxidasic and antioxidant properties are very helpful for winemakers. Nevertheless sulfur dioxide has a real potential health impact, particularly for sensitive consumers often highlighted by hygienists. Nowadays, a serious trend for “natural” wines (i.e. produced without any additives), as described by their producers, could be observed on the French market what match with a proliferation of wines elaborated without any sulfite addition.
Samples from 3 wine types were treated with a cationic exchange resin (7 lots) and stored for 8 years (47 samples). Forty-seven parameters were determined, including (1) important substrates with impact in white wine oxidation and (2) markers of oxidation. From group 1, sugars, elements, phenolic compounds, α-dicarbonyls and SO2 and from group 2, browning (A420), acetaldehyde, alkanals, furanic compounds were quantified.