Investigation of variety, typicality and vintage of French and German wines using front-face fluorescence spectroscopy

The potential of front-face fluorescence spectroscopy combined with chemometric methods was investigated for discriminating different wines according to variety, typicality and vintage. A total of 120 wines produced in France and Germany were investigated. Emission (275–450 nm) and excitation (250–350 nm) fluorescence spectra of phenolic compounds were recorded directly on the wine samples using a front-face fluorescence accessory. The emission spectra were characterised by a maximum at 376 nm and a shoulder at 315 nm and the excitation spectra showed two peaks located at about 260 and 320 nm. The shape of the spectra changed with wine samples, varying mainly in the maximum/shoulder intensity. Wine samples were evaluated using principal component analysis (PCA) and classified by factorial discriminant analysis (FDA). PCA performed on the whole collection of excitation spectra allowed a good discrimination between French and German wines. Using FDA, correct classification of typical and non-typical Beaujolais amounting to 95% was observed for the emission fluorescence data set. These results showed that fluorescence spectroscopic technique may provide useful fingerprints and mainly allow the identification of wines according to variety and typicality.