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…

IMPACT OF MUST NITROGEN DEFICIENCY ON WHITE WINE COMPOSITION DEPENDING ON GRAPE VARIETY

Nitrogen (N) nutrition of the vineyard strongly influences the must and the wine compositions. Several chemical markers present in wine (i.e., proline, succinic acid, higher alcohols and phenolic compounds) have been proposed for the cultivar Chasselas, as indicators of N deficiency in the grape must at harvest [1]. Grape genetics potentially influences the impact of N deficiency on grape composition, as well as on the concentration of potential indicators in the wine. The goal of this study was to evaluate if the che- mical markers found in Chasselas wine can be extended for other white wines to indicate N deficiency in the grape must.

OENOLOGICAL TANNINS FOR PREVENTING THE LIGHT-STRUCK TASTE IN WHITE AND ROSÉ WINES

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

VALORIZATION OF GRAPE WINE POMACE USING PULSED ELECTRIC FIELDS (PEF) AND SUPERCRITICAL CO₂ (SC CO₂) EXTRACTION

Wine grape pomace quantitatively and qualitatively represents the most important fraction of wine waste. Namely, this by-product makes ~ 20% of the total mass of vinified grapes, and it is characterized with high concentrations of polyphenolic antioxidants, as well as grape seed oil. Hence, valorization of wine pomace, as an alternative to traditionally employed disposal, has drown considerable interest in recent years. Earlier studies were mostly focused on the extraction of phenolics, while mechanisms enhancing the extraction of lipid fraction from grape pomace, as well as their impact on the grape seed oil quality are far less investigated.

EFFECTS OF INDUCED SUNBURN DAMAGES ON WHITE WINE PROPERTIES

Climate change is a great challenge for the environment and affects the wine industry as well. Sunburn damage of sensitive grapes increase with severe heat periods. Besides significant loss of yield sunburn, modifies sensory properties of the wines and may cause climate-related off-flavours. To initiate sunburn in a controlled way, in 2021 sunburn was directly induced in the vineyard with the GrapeBurner device, exposing grapes of the varieties Riesling and Pinot Blanc with UV and IR radiation. This device was first assembled by Kai Müller of the university in Geisenheim and consists of a carriage with 6 UV/IR lamps. A 15 min irradiation was applied in early September at 60°Oe. Due to the colder season in 2021 the grapes were not harmed by previous sunburn damage.

LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

In the Bordeaux vineyards, press red wine represents about 15% of the volume of wines. Valuing this large volume of press wine is necessary from an economic point of view, of course, but also because of their organoleptic contribution to the blend. Nevertheless, there is a lack of recent knowledge on the composition of press wines. This work aims to establish an initial assessment of their composition (aromatic and polyphenolic) and to set up hypothesis on to the links with their sensorial identity.