*3.2.2.3 Carbonylated compounds*

These compounds arise from the metabolism of yeasts by decarboxylation of the α-ketone acids formed in the biosynthesis of higher alcohols. They remain in the wine in small quantities, due to the strong reducing activity of yeast during fermentation. Sulfur dioxide and alcohols react to the pH of the wine with the carbonylated compounds, forming sulphydric combinations [69].
