Polyfunctional Thiols in Wine: Chirality, Precursor Stereochemistry, and Sauvignon blanc Clone Type
Liang Chen, Dimitra Capone, and David
Jeffery*
*The University of Adelaide, PMB1, Glen Osmond, Adelaide/South
Australia/5064, Australia (david.jeffery@adelaide.edu.au)
Impact odorants that significantly influence aromas of
fragrances, foods and beverages are of particular scientific
interest due to their presence across different commodities and
their high potency. One class of well-known impact odorants that
impart “tropical” aromas to wine is the polyfunctional thiols,
including 3-sulfanylhexan-1-ol (3-SH) and 3-sulfanylhexyl acetate
(3-SHA). Since their first identification in wine around two
decade ago, 3-SH and 3-SHA, also known as varietal thiols, have
been the focus of ongoing investigations due to their extremely
low sensory thresholds (ng/L) and aroma qualities reminiscent of
“passionfruit” and “grapefruit”.
Following our previous studies into 3-SH and 3-SHA in particular,
we have now applied chemical synthesis, developed and validated
new mass spectrometry-based stable isotope dilution analysis
(SIDA) methods, used a high-throughput fermentation robot, and
undertook studies to explore the enantiomeric distribution of
3-SH and 3-SHA in wines arising from five Sauvignon blanc clones.
The new analytical methods were also applied to a range of
commercial wines to investigate the chiral distribution of
varietal thiols and the potential fate of 3-SH in wine. The
fermentation trials provided insight into the stereochemical
relationship between 3-SH and 3-SHA and their diastereomeric
precursors present in the juice, providing a better understanding
of the formation and fate of polyfunctional thiols in wines.
Funding Support: Wine Australia
