Identification of amino acids in wines by one- and two-dimensional nuclearmagnetic resonance spectroscopy

Amino acids are minor compounds in wines, but they have a profound influenc e on wine quality, and amino acids composition can be used to differentiate wines according to the vine variety, geographical origin, and year of prod uction. The NMR signals of amino acids in NMR spectra are overlapped by the signals of other compounds present and especially by the signals of domina nt compounds such as water, ethanol, and glycerol. In this work we used 1D H-1 and C-13, 2D homonuclear COSY, TOCSY, and 2D heteronuclear HSQC and HMQ C pulse sequences, also with an incorporated WET pulse sequence element tha t allows the simultaneous suppression of several frequencies. Complete H-1 and C-13 NMR assignments for 17 amino acids commonly present in wine and of gamma -aminobutyric acid at pH 3 have been achieved in wine sample of Sauv ignon from the Coastal wine-growing region of Slovenia, vintage 1994.