Entwicklung einer analytischen Methode zur Bestimmung niedrigsiedender polyfunktionaler Thiole in österreichischen Weiß- und Rotweinen

Abstract

Development of an analytical method for the determination of low-boiling polyfunctional thiols in Austrian white and red wines . In the present study, an analytical method was developed and validated for the determination of the volatile thiol compounds 4-methyl-4-sulfanylpentan-2-one (4MSP), 3-sulfanylhexan-1-ol (3SH), and 3-sulfanylhexyl acetate (3SHA). This method was subsequently applied to quantify these compounds in a selection of Austrian white and red wines. The method demonstrated excellent linearity and a good precision. Quantitative analyses revealed a pronounced varietal dependence of the thiol profiles. Among the white wines examined, Sauvignon Blanc – unsurprisingly – exhibited particularly high concentrations of 4MSP. Both 3SH and 3SHA were detected in nearly all white wine samples, with 3SH consistently present at elevated levels compared to corresponding blank matrix samples. In the case of Gemischter Satz (field blend), substantial variability was observed, particularly in 3SH concentrations. In the red wine varieties, Blaufränkisch and Zweigelt, 3SH was also clearly present, whereas 3SHA was only sporadically or not at all detectable. Some Schilcher samples showed exceptionally high concentrations of 3SH. Compared to NICI- or PFB-based derivatization methods, the developed method has higher detection limits, but does not require halogenated reagents and thus complies with the principles of green chemistry. These findings highlight the significant influence of grape variety and vinification parameters on thiol composition and provide valuable insights for targeted aroma management in modern viticulture. As part of a forthcoming study, the method will be expanded to include three additional thiol compounds, alongside further optimisation of the analytical protocol.