Abstract
The sulfidic compounds in wine responsible for ‘reductive’ off-odours can be quantified by a
variety of analysis techniques. However, there is a lack of information on how the determined
concentrations from the different techniques relate to each other, and to the sensory perception of
these off-odours. The analysis of 50 white wines was conducted using gas chromatography with
sulfur chemiluminescence detector (GC-SCD) for the determination of ‘free’ and ‘salt-treated’
concentrations of hydrogen sulfide (H2S) and methanethiol (MeSH), as well as analysis of ‘free’
H2S using gas detection tubes (GDT). The wines also underwent sensory and compositional
analysis, including the colorimetric quantitation of Cu and its different fractions. The GDT and
GC-SCD measures of free H2S concentrations correlated well with each other (R2 > 0.87), albeit
with a positive 2-fold bias for GDTs, but poorly with the salt-treated GC-SCD measure of H2S (R2
< 0.13). The free and salt-treated MeSH concentrations had excellent agreement with each other
(R2 > 0.91). The sensory perception of the sulfidic off-odours was best described by attributes of
boiled egg/rotten egg and natural gas/sewerage/durian aromas. The white wines with the highest
ratings for both attributes had high concentrations of free H2S, free MeSH and/or salt-treated
MeSH, low Cu fraction I and II concentrations, but no clear link to the salt-treated H2S
concentrations. This study provides evidence supporting the importance of measuring free sulfidic
compounds rather than their bound forms when attempting to predict the perception of ‘reductive’
off-odours in white wine.
variety of analysis techniques. However, there is a lack of information on how the determined
concentrations from the different techniques relate to each other, and to the sensory perception of
these off-odours. The analysis of 50 white wines was conducted using gas chromatography with
sulfur chemiluminescence detector (GC-SCD) for the determination of ‘free’ and ‘salt-treated’
concentrations of hydrogen sulfide (H2S) and methanethiol (MeSH), as well as analysis of ‘free’
H2S using gas detection tubes (GDT). The wines also underwent sensory and compositional
analysis, including the colorimetric quantitation of Cu and its different fractions. The GDT and
GC-SCD measures of free H2S concentrations correlated well with each other (R2 > 0.87), albeit
with a positive 2-fold bias for GDTs, but poorly with the salt-treated GC-SCD measure of H2S (R2
< 0.13). The free and salt-treated MeSH concentrations had excellent agreement with each other
(R2 > 0.91). The sensory perception of the sulfidic off-odours was best described by attributes of
boiled egg/rotten egg and natural gas/sewerage/durian aromas. The white wines with the highest
ratings for both attributes had high concentrations of free H2S, free MeSH and/or salt-treated
MeSH, low Cu fraction I and II concentrations, but no clear link to the salt-treated H2S
concentrations. This study provides evidence supporting the importance of measuring free sulfidic
compounds rather than their bound forms when attempting to predict the perception of ‘reductive’
off-odours in white wine.
| Original language | English |
|---|---|
| Pages | 77 |
| Number of pages | 1 |
| Publication status | Published - 2024 |
| Event | In Vino Analytica Scientia (IVAS) 2024 - University of California Davis, Davis, United States Duration: 09 Jul 2024 → 12 Jul 2024 https://ivas2024.wixsite.com/ivas2024 https://b3ee8cec-6235-40d7-995c-d930e6340812.filesusr.com/ugd/74eb4e_00829b274d77493c98d8924f4de83896.pdf (Program and abstract book) |
Conference
| Conference | In Vino Analytica Scientia (IVAS) 2024 |
|---|---|
| Abbreviated title | Analytical chemistry for wine, brandy and spirits |
| Country/Territory | United States |
| City | Davis |
| Period | 09/07/24 → 12/07/24 |
| Other | The IVAS symposium provides a forum for researchers to present advanced research on the analytical science of grapes, wine, and spirits. Since the initial meetings in 1997 and 2001 (Bordeaux), IVAS has occurred every two years, albeit with a pause between 2019 to 2022 due to the global pandemic. For 27 years, IVAS has enabled us to convene, share knowledge and forge connections, and now in 2024, we attend the first IVAS meeting in the United States of America. |
| Internet address |