terclim by ICS banner
IVES 9 IVES Conference Series 9 CONTRIBUTION OF VOLATILE THIOLS TO THE AROMA OF RIESLING WINES FROM THREE REGIONS IN GERMANY AND FRANCE (RHEINGAU, MOSEL, AND ALSACE)

CONTRIBUTION OF VOLATILE THIOLS TO THE AROMA OF RIESLING WINES FROM THREE REGIONS IN GERMANY AND FRANCE (RHEINGAU, MOSEL, AND ALSACE)

Abstract

Riesling wines are appreciated for their diverse aromas, ranging from the fruity fresh characters in young vintages to the fragrant empyreumatic notes developed with aging. Wine tasters often refer to Riesling wines as prime examples showcasing terroir, with their typical aroma profiles reflecting the geographical provenance of the wine. However, the molecular basis of the distinctive aromas of these varietal wines from major Riesling producing regions in Europe have not been fully elucidated. In this study, new lights were shed on the chemical characterization and the sensory contribution of volatile thiols to Riesling wines from Rheingau, Mosel, and Alsace. First, Riesling wines (n = 46) from the three regions were collected and assessed for their aroma typicality by an expert panel. Based on sensory assessment, selected wines were examined for their global aroma profile by sensory guided odorant screening techniques (preparative high pressure liquid chromatography; gas chromatography–mass spectrometry/olfactometry (GC–MS/O); sensory evaluation), and several odorous zones (OZs) of interest resembling the original olfactory notes (citrus, tropical fruits etc.) of the initial wines were noted. The aroma descriptors, linear retention index, and mass spectra of the suspected chromatography peaks and their accompanying OZs of interest revealed the presence and importance of volatile thiols in Riesling wines analysed. Hence, selective silver ion solid phase extraction and multidimensional GC–MS/O were applied for further characterization of targeted thiol-relevant OZs, allowing tentative identification of unknown thiols, with one new mercapto monoterpenoid confirmed by orthogonal approach. Following the sensory guided qualitative screening efforts, a new and highly sensitive quantitation method based on chemical derivatization and liquid chromatography quadrupole Orbitrap high-resolution MS was developed for the analysis of a substantial number of known and newly identified volatile thiols in the wine set. Quantitative results confirmed the relevance of 13 odorous thiols in Riesling, with several of them presented at concentrations well over their perception thresholds, as 3-sulfanylhexanol for instance. Thus, the combination of the chemical analysis of thiols and the sensory evaluation made it possible to draw up regional profiles according to the origin of the wines.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Emilio De Longhi1,2,3, Liang Chen1, 2, †, Pascaline Redon1, 2, Christoph Schüssler4, Rainer Jung4, Claus Patz5, Doris Rau-Hut3, Philippe Darriet1,2

1. Université de Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33140 Villenave d’Ornon, France
2. Bordeaux Sciences Agro, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, F-33170 Gradignan, France
3. Hochschule Geisenheim University, Department of Microbiology and Biochemistry, Von-Lade-Str. 1, 65366 Geisenheim, Germany
4. Hochschule Geisenheim University, Department of Enology, Von-Lade-Str. 1, 65366 Geisenheim, Germany
5. Hochschule Geisenheim University, Department of Beverage Research, Von-Lade-Str. 1, 65366 Geisenheim, Germany †Current address: E. & J. Gallo Winery, 600 Yosemite Boulevard, Modesto, CA 95354, United States

Contact the author*

Keywords

Riesling wine aroma, Volatile thiols, Identification, Quantitation

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 GRAPE-ASSOCIATED MOLDS IN FRESH MUSHROOM AROMA PRODUCTION

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.

THE ROLE OF CELL WALL POLYSACCHARIDES IN THE EXTRACTION OF ANTHOCYANINS AND TANNINS: RESULTS, PERSPECTIVES OF A MORE POSITIVE CONTRIBUTION

The composition of grape berry cell walls was studied on two grape varieties, two years and two maturation levels at the same time as the extraction of anthocyanins and tannins. The chemical composition of skins, seeds, and pulps, focused on polyphenols and polysaccharides, was compared to the chemical composition in polyphenols after extraction from the skins in model solutions or after wine making of the berries. Polyphenols were mainly characterized by UPLC-MS and HPLC-SEC. Polysaccharides were characterized by analysis of the neutral sugar compositions, and also by the CoMPP (comprehensive micropolymer profiling) analysis, a new method which targets the functional groups of cell wall polysaccharides.

EFFECTS OF BIODYNAMIC VINEYARD MANAGEMENT ON GRAPE RIPENING MECHANISMS

Biodynamic agriculture, founded in 1924 by Rudolph Steiner, is a form of organic agriculture. Through a holistic approach, biodynamic agriculture seeks to preserve the diversity of agriculture and the existing interactions between the mineral world and the different components of the organic world. Biodynamic grape production involves the use of composts, herbal teas and mineral preparations such as 500, 501 and CBMT.
Several scientific studies have provided evidence on the effects of biodynamic farming on the soil, the plant and the wine. Numerous empirical opinions of wine growers support the existence of differences brought by such a management.

IMPACT OF HARVEST DATE ON THE FINE MOLECULAR COMPOSITION OF MUST AND BORDEAUX RED WINE (VAR. MERLOT, CABERNET SAUVIGNON). FOCUS ON ACIDITY AND SENSORY IMPACT AFTER FIVE YEARS OF AGING

Climate change has brought several impacts that are becoming increasingly intense during the last few years and put at risk the quality of the berries or even the plant’s sustainability. Such extreme climatic events impact the composition of the wine while modulating its quality and the consumer preferences (Tempère et al., 2019). The three most important changes that take place in the must are: 1) decrease acidity, 2) increase of the concentration of sugar, hence increase of alcohol in the wine, and 3) modification
of the sensory balance and the development for example of cooked fruit aromas.