α-Hydroxy Ketones, Acetoin and Hydroxy Pentanone, in Wines

Abstract

α-Hydroxy ketones, acetoin and hydroxy pentanone (3-hydroxy-2-pentanone and/or 2-hydroxy-3-pentanone) have been isolated from eight different European white wine brands and eight red wine brands and converted in acid solution to the corresponding vicinal diketones by steam distillation. The diketones formed have been analyzed by head-space gas chromatography of the distillate, with the aid of an electron capture detector. The mean contents of acetoin and hydroxy pentanone were in white wines 12 mg/l and 0.7 mg/l, the respective values in red wines being 46 mg/l and 3 mg/l.