Identification and Significance of Several Sulfur-Containing Compounds in Wine

Samples of German wines (Riesling, Scheurebe, Morio-Muskat, Bacchus) were continuously extracted with Freon 11:dichloromethane; the extracts were concentrated and submitted to GC-MS analysis. Six sulfur-containing compounds which were not previously reported in wine were identified by comparison of their mass spectra and GC retention times with those of authentic samples which are commercially available or were synthesized. The compounds and their approximate concentrations in wine are, respectively: cis and trans 2-methylthiophan-3-ol, 0.1 to 0.5 mg/L; 4-(methylthio)-butan-1-ol, 0.05 to 0.2 mg/L; 2-[[(methylthio)methyl]thio]ethanol, 0.01 to 0.05 mg/L; 5-(2-hydroxyethyl)-4-methylthiazole 0.005 to 0.05 mg/L; and 2-mercaptoethanol, 10 -5 mg/L or less. Odor threshold values using 15% aqueous ethanol were found to be at or above the concentrations for each compound measured.