ANALYTICAL PYROLYSIS AND THERMALLY ASSISTED HYDROLYSIS-METHYLATION OFWINE TANNIN

Condensed tannins from nines produced in Calabria, Italy, were purifie d by gel filtration on Sephadex LH-20. Tannin samples were subjected t o pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) and to the rmally assisted hydrolysis-methylation/gas chromatography/mass spectro metry (THM/GC/MS), the latter in the presence of tetramethylammonium h ydroxide. The tannin fragments produced by PY/GC/MS were identified an d ascribed the B ring of the monomeric flavanoids. The methyl derivati ve of the A ring of the monomeric flavanoids was evident in the THM/GC /MS trace, along with permethylated derivatives of phenolic acids and fatty acids. Control wines and the corresponding samples aged in oak w ood barrels were compared as to PY/GC/MS quantitative data of selected pyrolysis fragments.