terclim by ICS banner
IVES 9 IVES Conference Series 9 REVEALING THE ORIGIN OF BORDEAUX WINES WITH RAW 1D-CHROMATOGRAMS

REVEALING THE ORIGIN OF BORDEAUX WINES WITH RAW 1D-CHROMATOGRAMS

Abstract

Understanding the composition of wine and how it is influenced by climate or wine-making practices is a challenging issue. Two approaches are typically used to explore this issue. The first approach uses che-mical fingerprints, which require advanced tools such as high-resolution mass spectrometry and mul-tidimensional chromatography. The second approach is the targeted method, which relies on the widely available 1-D GC/MS, but involves integrating the areas under a few peaks which ends up using only a small fraction of the chromatogram.

Here, we employ state-of-the-art machine learning methods to optimize the analysis of 1-D GC/MS chromatograms. Specifically, we aim to determine whether these chromatograms contain valuable in-formation beyond the manually extracted peaks typically utilized in the targeted approach.

To explore those questions, we analyzed 4 different types of 1-D raw chromatograms (3 SIM and 1 full-scan) of 80 wines (12 vintages from 7 estates of the Bordeaux area. We first applied nonlinear dimensio-nality reduction techniques (T-SNE and UMAP) to the chromatograms to obtain 2D maps. In the resul-ting maps, wines of the same estates across multiple vintages tended to form clear clusters, whose spatial distribution reflected the geography of the Bordeaux wine region. This indicated that, for this particular set of wine, the raw chromatograms are highly informative about terroir and wine identity.

Next, we applied cross-validated classifiers to the raw chromatograms and found that we could recover perfectly well estates identity independent of vintage. By contrast, performance on vintage classifica-tion was much lower with a maximum performance of 50% correct.

Crucially, we found that the entire chromatogram is informative with respect to both of these variables. Thus, the extraction of specific peaks of the chromatogram to quantify the concentration of 32 known chemical compounds–discarding the rest of the chromatograms–led to worse classification perfor-mance, suggesting that estate identity is distributed over a large chemical spectrum, including many molecules that have yet to be identified.

In addition, the GC raw data can be used to predict the ratings of a professional wine critic (Robert Par-ker) above chance, thus suggesting that GC might also contain information about the organoleptic pro-perties of wine.

Overall, this study demonstrates the strong potential of raw chromatogram analysis for wine characte-rization and identification.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Michael Schartner¹, Jeff M. Beck², Justine Laboyrie³, Laurent Riquier³, Stephanie Marchand3*, Alexandre Pouget4*

1. Center for the Unknown. Champalimaud Institute. Lisbon. Portugal. 
2. Duke university. USA
3. Université de Bordeaux, ISVV, INRAE, UMR 1366 OENOLOGIE, 33140 Villenave d’Ornon, France
4. Département des neurosciences fondamentales. Université de Genève. Suisse. 

Contact the author*

Keywords

Machine learning, Wine composition, Sensorial classification, Terroir

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

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.

CHARACTERIZATION AND IDENTIFICATION OF YEAST BIOACTIVE PEPTIDES RELEASED DURING FERMENTATION AND AUTOLYSIS IN MODEL WINE

Aging wine on lees is a consolidated practice during which some yeast components (e.g., polysaccharides,
proteins, peptides) are released and solubilized in wine thus, affecting its stability and quality.
Apart from the widely studied mannoproteins, the role of other yeast components in modulating wine
characteristics is still scarce. Wine peptides have been studied for their contribution to taste, antioxidant,
and antihypertensive potentials. However, the peptides detected in wine can be influenced by the
interaction between yeasts and grape components.

A synthesis approach on the impact of elevated CO2 on berry physiology and yield of Vitis vinifera

Besides the increase in global mean temperature the second main challenge of a changing climate is the increase in atmospheric carbon dioxide (CO2) in relation to physiology and yield performance of grapevines. The benefits of increasing CO2 levels under greenhouse environment or open field studies have been well investigated for various annual crops. Research under free carbon dioxide enrichment on field-grown perennial plants such as grapevines is limited to a few studies. Further, chamber and greenhouse experiments have been conducted mostly on potted vines under eCO2 conditions.

INOCULATION OF THE SELECTED METSCHNIKOWIA PULCHERRIMA MP1 AS A BIOPROTECTIVE ALTERNATIVE TO SULFITES TO PREVENT BROWNING OF WHITE GRAPE MUST

Enzymatic browning (BE) of must is caused by polyphenol oxidases (PPOs), tyrosinase and laccase. Both PPOs can oxidize diphenols such as hydroxycinnamic acids (HA) to quinones, which can later polymerize to form melanins [1], which are responsible of BE in white wines and of oxidasic haze in red wines. SO₂ is the main tool used to protect must from BE thanks to its capacity to inhibit PPOs [2]. However, the current trend in winemaking is to reduce and even eliminate this unfriendly additive. Among the different possible alternatives for protecting must against BE, the inoculation with a selected Metschnikowia pulcherrima MP1 is without any doubt one of the most promising ones.

WINE WITHOUT ADDED SO₂: OXYGEN IMPACT AND EVOLUTION ON THE POLYPHENOLIC COMPOSITION DURING RED WINE AGING

SO₂ play a major role in the stability and wine during storage. Nowadays, the reduction of chemical input during red winemaking and especially the removing SO₂ is a growing expectation from the consumers. Winemaking without SO₂ is a big challenge for the winemakers since the lack of SO₂ affects directly the wine chemical evolution such as the phenolic compounds as well as its microbiological stability.