Use of modern nuclear magnetic resonance spectroscopy in wine analysis: determination of minor compounds Original Research Article

In our work, the capacity of 1D and 2D 1H and 13C homo and heteronuclear nuclear magnetic resonance (NMR) experiments were examined for the characterization of amino acids and anthocyanins, the “minor” but important compounds of wine. The compositions of amino acids and anthocyanins influence the flavour of wines and their composition could be used to differentiate wines according to the vine variety, geographical origin and year of production. Anthocyanins are also the major components responsible for the red wine color and they have a wide range of biochemical and pharmacological effects such as antimicrobial and antioxidant activities. We use the signal intensities in 1D 1H NMR spectra in the chemometric analysis of white wines from Slovenia. The use of signals of seven amino acids gives a good separation of wines according to the vine variety, while adding also the signal intensities of glycerol, butylene glycol and succinic acid, the separation of wines between the Coastal and continental part of Slovenia was achieved. By using 1D and 2D NMR experiments the reliable assignment of 1H and 13C resonances of anthocyanins, peonidine 3-glucoside, petunidine 3-glucoside, cyanidine 3-glucoside, delphinidine 3-glucoside and malvidine 3-glucoside in CD3OD was established, which will serve as a tool for the identification of a particular fraction in liquid chromatographic analysis.