Characterization of chemical compounds susceptible to be extracted from cork by the wine using GC-MS and 1H NMR metabolomic approaches

This work presents a metabolomics study of cork by gas chromatography-mass spectrometry (GC-MS) and 1H nuclear magnetic resonance (NMR) spectroscopy to characterize compounds susceptible to be extracted from cork by the wine in an attempt to find a relationship between the content of these compounds and the geographical origin of cork. Cork from eleven geographical regions was studied, five from Portugal and six from Spain. Unsupervised pattern recognition techniques unveiled three main clusters of regions according to their chemical similarity but not related with geographical proximity. Nineteen compounds were found to be responsible for the clusters, including terpenes (trans-squalene, friedelin, camphene, trans-3-pinanone, 1-terpinen-4-ol, two sesquiterpenes), polyphenols (vescalagin, castalagin), among others (pyrogallol, glucosan, sitost-4-en-3-one, o-cymene, quinic acid, five unknowns). These preliminary results unveiled the potential for a more efficient selection of cork planks for stoppers production based on the compounds susceptible to be extracted from cork by the wine.