terclim by ICS banner
IVES 9 IVES Conference Series 9 VOLATILE AND GLYCOSYLATED MARKERS OF SMOKE IMPACT: EVOLUTION IN BOTTLED WINE

VOLATILE AND GLYCOSYLATED MARKERS OF SMOKE IMPACT: EVOLUTION IN BOTTLED WINE

Abstract

Smoke impact in wines is caused by a wide range of volatile phenols found in wildfire smoke. These compounds are absorbed and accumulate in berries, where they may also become glycosylated. Both volatile and glycosylated forms eventually end up in wine where they can cause off-flavors. The impact on wine aroma is mainly attributed to volatile phenols, while in-mouth hydrolysis of glycosylated forms may be responsible for long-lasting “ashy” aftertastes (1).

In order to assess smoke impact, a selection of volatile and glycosylated phenols is proposed, mainly based on research from Australia (2, 3). It includes the volatile phenols guaiacol, 4-methylguaiacol, ortho-, meta- and para- cresol, phenol, syringol, and 4-methylsyringol, as well as their glycosylated forms guaiacol rutinoside, 4-methylguaiacol rutinoside, cresol rutinoside, phenol rutinoside, syringol gen-tiobioside, and 4-methylsyringol gentiobioside. The accurate and reproducible measurement of these compounds is now possible, due to the commercial availability of standards and isotopic analogues.

In this study, we investigated the stability of these markers in bottled wines from smoke-exposed grapes, during a two-year timeframe. Wines monitored were a Chenin Blanc and a Chardonnay (whites), a Grenache (rosé), two Cabernet Sauvignons, a Zinfandel and a Grenache (reds).

No significant increases in guaiacol were observed in the white and rosé wines. Slight increases (2-3 μg/L) were observed in red wines, with the exception of the Pinot Noir (9 μg/L). Non-significant to slight increases were observed for phenol, except in the Zinfandel (10 μg/L). Large increases were observed for syringol in red wines only, especially in Cabernet Sauvignons (up to 60 μg/L). No significant increases were observed for the other volatile phenols measured.

All measured glycosylated markers were stable, in all wines. Therefore, increases in volatile phenols, when they happened, were not explained by the hydrolysis of corresponding glycosylated forms measured.

The observed increases in guaiacol and syringol, as well as the stability of the glycosylated forms measured, are consistent with results from a previous study (4). The stability of glycosylated markers makes them relevant in identifying wines from smoke exposed grapes, possibly for many years after bottling. A limitation is that some smoke impacted wines might show normal or even non-detectable levels of these glycosylated markers.

 

1. Christine M. Mayr, Mango Parker, Gayle A. Baldock, Cory A. Black, Kevin H. Pardon, Patricia O. Williamson, Markus J. Herderich, and I. Leigh Francis.  2014. Determination of the Importance of In-Mouth Release of Volatile Phenol Glycoconjugates to the Flavor of Smoke-Tainted Wines. Journal of Agricultural and Food Chemistry  62 (11), 2327-2336
2. Hayasaka, Y., Parker, M., Baldock, G.A., Pardon, K.H., Black, C.A., Jeffery, D.W. and Herderich, M.J. (2013) Assessing the impact of smoke exposure in grapes: development and validation of a HPLC-MS/MS method for the quantitative analysis of smoke derived phenolic glycosides in grapes and wine. Journal of Agricultural and Food Chemistry 61, 25–33.
3. Krstic, M.P., Johnson, D.L. and Herderich, M.J. (2015) Review of smoke taint in wine: smoke-derived volatile phenols and their glycosidic metabolites in grapes and vines as biomarkers for smoke exposure and their role in the sensory perception of smoke taint. Australian Journal of Grape and Wine Research 21, 537–553.
4. Renata Ristic R., Lieke van der Hulst L., Dimitra L. Capone, and Kerry L. Wilkinson. Impact of Bottle Aging on Smoke-Tainted Wines from Different Grape Cultivars. 2017.
5. Journal of Agricultural and Food Chemistry 65 (20), 4146-4152

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Eric Hervé¹, Darren Gullick¹ , Azeem Hasan¹, Anindya Pradhan¹, Gordon Burns¹

1. ETS Laboratories, 899 Adams St. Suite A, St. Helena, CA 94574, USA

Contact the author*

Keywords

smoke impact, volatile phenols, glycosylated phenols

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

INVESTIGATION INTO MOUSY OFF-FLAVOR IN WINE USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH STIR BAR SORPTIVE EXTRACTION

Mousy off-flavor is one of the defects of microbial origin in wine. It is described as a particularly unpleasant defect reminiscent of rodent urine (a “dirty mouse cage”), and grilled foods such as popcorn, rice, crackers, and bread crust. Prior to the 2010s, mousiness was very uncommon but it has been becoming more frequent in recent years. It is often associated with an increase in pH as well as certain oenological practices, which tend to significantly decrease the use of sulfur dioxide.

Read More

FOURIER TRANSFORM INFRARED SPECTROSCOPY IN MONITORING THE WINE PRODUCTION

The complexity of the wine matrix makes the monitoring of the winemaking process crucial. Fourier Transform Infrared Spectroscopy (FTIR) along with chemometrics is considered an effective analytical tool combining good accuracy, robustness, high sample throughput, and “green character”. Portable and non-portable FTIR devices are already used by the wine industry for routine analysis. However, the analytical calibrations need to be enriched, and some others are still waiting to be thoroughly developed.

Read More

NEW INSIGHTS INTO THE FATE OF MARKERS INVOLVED IN FRESH MUSHROOM OFF-FLAVOURS DURING ALCOHOLIC FERMENTATION

The fresh mushroom off-flavour (FMOff) has been appearing in wines since the 2000s. Some C8 compounds such as 1-octen-3-one, 1-octen-3-ol, 1-hydroxyoctan-3-one, 3-octanol and others are involved in this specific off-flavour [1-3]. At the same time, glycosidic precursors of some FMOff compounds have been identified in musts contaminated by Crustomyces subabruptus [4], highlighting the role of aroma precursors in this specific taint. However, the fate of these volatile molecules and glycosidic fractions during fermentation is not well known.

Read More

ASSESSMENT OF ‘DOLCETTO’ GRAPES AND WINES FROM DIFFERENT AREAS OF OVADA DOCG

Dolcetto (Vitis vinifera L.) is one of the traditionally cultivated varieties in Piedmont (north-east Italy). Dolcetto wines have long been associated with local consumption and they are little known internationally. In particular, the Ovada area (south-east Piedmont), even if it represents a small share of the regional PDO Dolcetto production, is one of the oldest and vocated territory, giving wine also suitable for aging. In this study, the basic composition and phenolic content of Dolcetto grapes for Ovada DOCG wines have been investigated in three different vintages (2020-2022), as well as the main aspects of the derived commercial and experimental wines (basic parameters, phenolics, volatile compounds, sensory properties).

Read More

ANALYZING THE ROLE OF ELEMENTAL SULFUR IN GRAPE JUICE ON THE DEVELOPMENT OF POLYFUNCTIONAL MERCAPTANS IN SAUVIGNON BLANC WINES

Sauvignon blanc is characterized by distinctive aromas, both fruity and herbaceous. The “green” character has been attributed to the methoxypyrazines, while the “fruity” character is associated with polyfunctional mercaptans . Polyfunctional mercaptans are of great significance due to their high impact on wines and associated low perception thresholds.
Elemental sulfur (S⁰) is widely used to protect grapevines from powdery mildew.

Read More