terclim by ICS banner
IVES 9 IVES Conference Series 9 NOVEL BENZENETHIOLS WITH PHENOLS CAUSE ASHY, SMOKE FLAVOR PERCEPTION IN RED WINES

NOVEL BENZENETHIOLS WITH PHENOLS CAUSE ASHY, SMOKE FLAVOR PERCEPTION IN RED WINES

Abstract

Smoke impacts on wines are becoming a worldwide problem; the size and severity of wildfires increasing due to influences from changing climates.¹ For over a century, wines have been known to have a unique issue of absorbing chemical compounds derived from wildfire smoke wherein the flavor of the subsequent wine becomes ashy, rubbery, campfire-like, and smoky.² The economic impacts of a smoke-impacted wine can last for years depending on the grape varietal, costing Oregon and Washington states in the United States over a billion dollars from the 2020 wildfires, as an example.³ While years of research have indicated elevated concentrations of smoke-related compounds, such as guaiacol and syringol, in wines after smoke events, unfortunately, replicating the sensory experience using smoke-associated phenols has not had much success.⁴ In our study, we found elevated concentrations of benzenethiols in smoke-impacted wines. 13C-labelled smoke data suggests phenol conversion into benzenethiol. A follow-up sensory experiment showed that the ashy aftertaste of smoke-impacted wines can be replicated by adding elevated amounts of benzenethiols and phenols to a wine that was previously not influenced by smoke. The novel targets could lead to better fining methods to remove the unwanted benzenethiols to achieve the flavors and aromas desired by winemakers and consumers.

1. Total Wildland Fires and Acres (1983-2021). (n.d.). National Interagency Fire Center. Retrieved September 1, 2022, from https://www.nifc.gov/fire-information/statistics
2. Grazzi-Soncini, G. Wine: Classification, Tasting, Qualities, and Defects. 1892. A.J. Johnston, Supt. State Printing. California, United States.
3. Adams, A. (2021, January 20). 2020 Fires Caused $3.7 billion in losses for Wine Industry. Wine Business.
4. Kennison, K., Wilkinson, K. L., Williams, H., Smith, J., & Gibberd, M. (2007). Smoke-derived Taint in Wine: Effect of Postharvest Smoke Exposure of Grapes on the Chemical Composition and Sensory Characteristics of Wine. Journal of Agricultural and Food Chemistry, 55(46), 10897–10901.

 

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Elizabeth Tomasino1, Léa Delcros1,2,3, Sylvie Collas2, Marion Hervé1, Bruno Blondin3, Aurélie Roland3*

1. MHCS, Epernay, France
2. Comité Champagne, Epernay, France
3. SPO, Univ Montpellier INRAE, Institut Agro, Montpellier, France

Contact the author*

Keywords

smoke, guaiacol, sensory, benzenethiol

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

INVESTIGATION OF MALIC ACID METABOLIC PATHWAYS DURING ALCOHOLIC FERMENTATION USING GC-MS, LC-MS, AND NMR DERIVED 13C-LABELED DATA

Malic acid has a strong impact on wine pH and the contribution of fermenting yeasts to modulate its concentration has been intensively investigated in the past. Recent advances in yeast genetics have shed light on the unexpected property of some strains to produce large amounts of malic acid (“acidic strains”) while most of the wine starters consume it during the alcoholic fermentation. Being a key metabolite of the central carbohydrate metabolism, malic acid participates to TCA and glyoxylate cycles as well as neoglucogenesis. Although present at important concentrations in grape juice, the metabolic fate of malic acid has been poorly investigated.

IMPACT OF METSCHNIKOWIA PULCHERRIMA DURING FERMENTATION ON AROMATIC PROFILE OF VIDAL BLANC ICEWINE

Non-Saccharomyces yeasts not only increase microbial diversity during wine fermentation, but also have a positive effect on improving wine aroma. Among these non-Saccharomyces yeast species, Metschnikowia pulcherrima is often studied and used in winemaking in recent years, but its application in icewine has been rarely reported. In this study, indigenous M. pulcherrima strains and Saccharomyces cerevisiae strains (commercial and indigenous strains) were sequentially inoculated for icewine fermentations; meanwhile, pure S. cerevisiae fermentations were used as the control; indigenous strains used above were screened from spontaneous fermentations of Vidal blanc icewine.

GRAPE SPIRITS FOR PORT WINE PRODUCTION: SCREENING THEIR AROMA PROFILE

Port is a fortified wine, produced from grapes grown in the demarcated Douro region. The fortification process consists in the addition of a grape spirit (77% v/v) to the fermenting juice for fermentation interruption, resulting in remaining residual sugars in the wine and increased alcohol content (19-22%). The approval of grape spirits follows the Appellation (D.O. Port wine) rules1 and it is currently carried out based on analytical control and on sensory evaluation done by the public Institute that upholds the control of the quality of Douro Appellation wines. However, the producers of Port wines would like to have more information about quality markers of grape spirits.

INFLUENCE OF THE NITROGEN / LIPIDS RATIO OF MUSTS ON THE REVELATION OF AROMATIC COMPOUNDS IN SAUVIGNON BLANC WINE

Production of volatile compounds by yeast is known to be modulated by must nitrogen. Nevertheless, various parameter of must quality have an impact on yeast fermentation. In this study we propose to evaluate the impact of nitrogen / lipids balance on a Sauvignon Blanc grape juice (Val de Loire).
Must was prepared from the same grapes at pilot scale. Three modalities were carried out: direct pressing, direct pressing with a pre-fermentation cold stabulation and pellicular maceration before pressing.

OPTIMIZING THE IDENTIFICATION OF NEW THIOLS AT TRACE LEVEL IN AGED RED WINES USING NEW OAK WOOD FUNCTIONALISATION STRATEGY

During bottle aging, many thiol compounds are involved in the expression of bouquet of great aged red wines according to the quality of the closure.1,2 Identifying thiol compounds in red wines is a challenging task due several drawbacks including, the complexity of the matrix, the low concentration of these impact compounds and the amount of wine needed.3,4
This work aims to develop a new strategy based on the functionalisation of oak wood organic extracts with H₂S, to produce new thiols, in order to mimic what can happen in red wine during bottle aging. Following this approach and through sensory analysis experiments, we demonstrated that the vanilla-like aroma of fresh oak wood was transformed into intense “meaty” nuances similar to those found in old but non oxidized red wines.