δ18O of wine ethanol for fraud detection

In the last 10 years the demand for alcoholic products (wine and distillates) has increased by around 8.6 % (source: VINEXPO 2011). Price increases and difficult access to raw materials have encouraged sophistication in the oenological field (source: “Alto Commissario per la lotta alla contraffazione” – 2008 Report). Since 1986, the European Union and the Organisation Internationale de la Vigna et du Vin (OIV) have established some official isotopic analytical methods in order to detect the illegal addition of sugar and water to wine and to enable geographical traceability (OIV MA-AS-311-05, OIV MAAS2-12, OIV MA-AS-312-06). Recently a new isotopic method for improving the detection of water added to orange juice has been proposed (Jamin et al., 2003; Monsallier-Bitea et al., 2006). The method is based on determining the 18O/16O isotope ratio of ethanol derived from sugar fermentation using a pyrolyser coupled to an IRMS. In this study we apply this method in order to identify the origin of ethanol from grapes (N=60), cereals and fruit (N=60) and synthetic products (N=5). The δ18O values ranged from +26 to +36 ‰ in wine, +17 to +26‰ in cereal distillates and from -2 to +12‰ in synthetic ethanol.