Wine lovers can now relax knowing they have purchased the real deal after scientists developed a new technique that exactly pinpoints the origin of their tipple. The breakthrough could help distinguish top-quality wine from fake versions flooding the market, rather than relying on taste alone.
The team could even tell the difference between wine on different estates on opposite banks of the river Garonne in Bordeaux.
Wines are made up of thousands of molecules – with the concentrations fluctuating depending on the composition and variety of grapes used, the structure of the vineyard’s soil, and the practices of the winegrower. Even if the variations between these things are small, they can have a significant impact on the taste of a bottle of wine.
This makes it difficult to trace a wine’s precise origin based on senses alone.
However, amid a rise of counterfeiting in the sector, tools to accurately determine the identity of wines are becoming increasingly important. For years researchers have studied this, trying to discover whether there is a chemical signature specific to each estate which can in turn pinpoint where a wine comes from.
However, their efforts have frequently been to no avail. “This is due to the great complexity of wines and the limitations of the methods used, which are a bit like looking for a needle in a haystack,” said Study author Professor Alexandre Pouget at the University of Geneva.
One such method is gas chromatography, which consists of separating the components of a mixture – in this case the wine. This eventually produces a chromatogram, showing ‘peaks’ which indicate molecular separations.
But, because of how many molecules a wine is comprised of, the ‘peaks’ end up being extremely numerous – making analysis challenging. To rectify this, Professor Pouget’s team combined gas chromatography with artificial intelligence tools which eventually created an algorithm that identified recurring patterns in sets of information.
Dr. Michael Schartner, who was the study’s first author, explained: “This method allowed us to consider each wine’s complete chromatograms – which can comprise up to 30,000 points – and to summarise each chromatogram, plus ‘background noise’, into two X and Y coordinates.
“This process is called dimensionality reduction.”
They trialled this with seven red wines from sever major estates in the region of Bordeaux, placing the coordinates of each one on a graph.
Vintages from the same estate ended up grouped together on the basis of their similar chemical compositions.
Study co-author Professor Stephanie Marchand of the Institute of Vine and Wine Science at the University of Bordeaux, said: “This allowed us to show that each estate does have its own chemical signature.
“We also observed that three wines were grouped together on the right and four on the left, which corresponds to the two banks of the Garonne on which these estates are located,” said Marchand. The research paper, published in the journal Communications Chemistry, said the method used identified the geographical origin of each wine with 100 percent accuracy.
The next step will be to trial the method further, on a larger sample of wine. Professor Pouget commented: “This research provides new insights into the components of a wine’s identity and sensory properties. “It also paves the way for the development of tools to support decision-making in the wine sector and to combat counterfeiting more effectively.”
Produced in association with SWNS Talker
