Quantitative determination of 4-mercapto-4-methylpentan-2-0ne in Sauvignon wines

Abstract

4-mercapto-4-methylpentan-2-one (4MMP), a powerful aromatic component from Sauvignon variety, is present at trace levels in the wines from this cultivar. A method is proposed ta measure the amount of 4MMP in Sauvignon wines. It combines the extraction of wines volatile constituents using a dynarnic headspace technique and the selective reaction between thiols and p-hydroxymercuribenzoatc (pHMB). This combination is reversible in presence of an excess of cystein or glutathione. Finally, the organic extract is injected on agas chromatograph coupled with a flame photometric detector. Using this method, 4MMP content in Sauvignon wines can be determined with good repetability and sensitivity. These results enable us to evalue the incidence of viticultural and oenological aspects on the level of this aromatic component in Sauvignon wines.