A METHOD FOR THE DETECTION OF CARBONYL-COMPOUNDS IN WINE - GLYOXAL AND METHYLGLYOXAL

Wine aldehydes were identified as O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine derivatives by GC-MS or with a GC-electron-capture detector. This method has been used to evaluate levels of glyoxal and methylglyoxal in wine. Reproducibility and linearity studies gave satisfying results. Glyoxal and methylglyoxal are formed during fermentation. Among the factors affecting their production, high musts pH increased the levels found in the corresponding wines. Various microorganisms of the wine such as Saccharomyces cerevisiae and Leuconostoc oenos can produce glyoxal and methylglyoxal. The concentrations in Sherry wines were particularly high. Because of the toxicological properties of these substances, their determination and the knowledge of their metabolism by wine microorganisms are very important.