Metabolomics detects copycat Provence rosé wines

Researchers in France have developed a method of distinguishing counterfeit from legitimate Provence rosé wines using chemical markers.

The work has been prompted by the increasing popularity of Provence rosé wines around the world, which has made them vulnerable to fraud, leading to significant economic damage and reputational damage, according to the team, which has published its findings in the journal Food Chemistry.

The paper notes that Provence rosé represents a major worldwide for French producers, with nearly 62 million bottles of wine exported worldwide in 2022.

The scientists set out to discover polyphenol metabolites generated during the cultivation and processing of wines that could serve as marker compounds and allow suspect wines to be authenticated or confirmed as counterfeit.

The polyphenol profile of wines depends on factors like grape variety, wine-making process, geographic origin and the age of the wine, and hypothetically could be used to narrow down the growing location of the wine, colloquially known as the 'terroir.'

While polyphenol concentrations have been used to trace the source of red wines, the new study is thought to be one of the first to look specifically at rosé wines, uses a new workflow based on liquid chromatography/high-resolution mass spectrometry (LC/HRMS), and according to the scientists is the first to directly analyse wine metabolites.

Using the analytical technique, they identified 1,300 potential metabolites from a set of 30 Provence, non-Provence, and imitation Provence wines. They narrowed down the field to three compounds – acuminoside, tetrahydroxydimethoxyflavone and 5′-methoxycastavinol – that could be used to distinguish authentic wines from copies with an accuracy of more than 93 per cent.

"This study constitutes a proof-of-concept to use the molecular information to authenticate genuine rosé wines of Provence from their imitations," write the authors in the paper. "Furthermore, our finding also materialised at the molecular level the concept of terroir for rosé wines."

Photo by Raissa Lara Lütolf (-Fasel) on Unsplash