25 Years authentication of wine with stable isotope analysis in the European Union – Review and outlook

¹ Bavarian Health and Food Safety Authority (LGL), 97082 Würzburg, Germany
² Landesuntersuchungsamt Rheinland-Pfalz, Institut für Lebensmittelchemie und Arzneimittelprüfung, 55129 Mainz, Germany

Abstract

The implementation of stable isotope applications in official food analyses began in 1990. At that time the first method to detect sucrose from sugar beet or sugar cane in wine by Deuterium-Nuclear Magnetic Resonance (²H-NMR) of ethanol, also known as SNIF-NMR^®-Method became adopted officially by the European Commission. This was a milestone for an improved authentication of wines and other food stuffs. In connection with methods using Isotope Ratio Mass Spectrometry (IRMS), stable isotope ratio analysis is one of the most powerful analytical tools for authentication of wine. The fundamentals of biotic and abiotic stable isotope fractionation and the analytical methods which are used in authentication of wine are summarized. Principles of authentication of some wine constituents like sugar, ethanol, organic acids, glycerol, and carbon dioxide as well as proof of geographic origin are reviewed. By selected example of anonymized cases, proof of adulterations (e.g. chaptalization, addition of water or mislabeling) using monovariate, bivariate, and multivariate data evaluations are discussed. It is shown that for this purpose databanks are generally indispensable. In their absence cut-off values, derived from long-term observations help to detect clear adulterations.