Wine authenticity by quantitative 1H NMR versus multitechnique analysis: a case study
Résumé
Food counterfeit is a major issue for food industries. In the case of wines, there can be multiple forgeries such as geographical, vintage, or varietal mislabeling. For the last 10 years, the use of quantitative 1H NMR (q-NMR) for food authentication has experienced an enormous increase. This study was based on a comparative evaluation of the results obtained for three sets of authentic high-valued wines and suspected wines. Two methodologies have been followed: (i) the usual wine analysis, based on the utilization of multiple techniques, which is the traditional way of analysis for wine authentication and (ii) q-NMR profiling, the alternative proposed method. For wine comparison, an original approach based on similarity score (S-score) by analogy to the Z-score calculation was developed. A limit of four S-scores outside the range − 2/2 has been, arbitrary, defined to reveal that wines are different using q-NMR analysis. Data treatments allowed the extraction of discriminating parameters, some of which were common to both approaches while others could be linked to the techniques’ capabilities showing the complementarity of the two approaches. This study demonstrated the potential of q-NMR in wine authentication by comparative analysis with authentic samples. The q-NMR alternative method has also the advantages of rapidity (around 20 min including sample preparation, analysis, and data treatment) and low volume (0.5 mL), which is a prerequisite for analyzing priceless wines.