Studies on Quality of Fruit Wine Vinegars (Part 1) Decrease in the Amount of Residual Sulfur Dioxide in Wine Vinegars during Storage when Bottles Have Been Opened

Abstract

In order to investigate the decrease in the residual SO₂ amount following the opening bottles, six wine vinegars produced in Europe were tested.
1. The highest amount of acetaldehyde was detected in sherry vinegar, then in balsamic vinegar, white wine vinegar, and red wine vinegar in that order.
2. Tartaric acid accounted for some 50% of the total non-volatile organic acids in the wine vinegars. Pyruvic acid was detected at concentrations of 10-25 μg/g in four samples, and in trace amounts in the remaining two samples. No α-keto glutaric acid was detected.
3. Most of the SO₂ in the wine vinegars was of the bound type. Little or only a trace amount of free SO₂ was detected.
4. The amounts of SO₂ in both the bound and free types were higher in wine than in wine vinegar.
5. The total amount of residual SO₂ in the wine vinegar decreased following the opening of the bottles in a similar pattern for five samples, while a rapid decrease was observed in one sample of red wine vinegar.
6. The total SO₂ amounts decreased faster in the wine vinegars than in the wine. It was suggested that the decrease depended on the type and amount of wine vinegar components that could be bound to SO₂, as well as that the low pH value could be a factor.