Determination of authenticy, regional origin, and vintage of Slovenian wines using a combination of IRMS and SNIF-NMR analyses

The authenticity and geographical origin of wines produced in Slovenia were investigated by a combination of IRMS and SNIF-NMR methods. A total of 102 grape samples of selected wines were carefully collected in three differen t wine-growing regions of Slovenia in 1996, 1997, and 1998. The stable isot ope data were evaluated using principal component analysis (PCA) and Linear discriminant analysis (LDA). The isotopic ratios to discriminate between c oastal and continental regions are the deuterium/hydrogen isotopic ratio of the methylene site in the ethanol molecule (D/H)(II) and delta C-13 values ; including also delta O-18 values in the PCA and LDA made possible separat ion between the two continental regions Drava and Sava. It was found that d elta O-18 values are modified by the meteorological events during grape rip ening and harvest. The usefulness of isotopic parameters for detecting adul teration or watering and to assess the geographical origin of wines is impr oved only when they are used concurrently.