In Port wine, isomers of glycerol and acetaldehyde acetals have been found at total contents ranging from 9.4 to 175.3 mg/L. During oxidative aging, the concentrations of the 5-hydroxy- 2-methyl-1, 3-dioxane and 4-hydroxymethyl-2-methyl-1, 3-dioxolane isomers increased with time showing a linear correlation (r> 0.95). The flavor threshold for the mixture of the four isomers was evaluated in wine at 100 mg/L. Thus, it is expected that they contribute to “old ...
