IDENTIFICATION OF OENOLOGICAL TANNINS EXTRACTED FROM OAK WOOD

Our study is dealing with the determination of the origin of oenological tannins using the modified OIV procedure. The method is based on HPLC analyses of proanthocyanidol content (catechin, epicatechin, epigallocatechin, epicatechin-3-O-gallate and epigallocatechin-3-O-gallate) after thioacidolysis - thiolytic cleavage of the flavonol intermonomer linkages in proanthocyanidols under heat in an acid medium. The purpose of the study was to differentiate oenological tannins gained from Quebracho cortex and tannins extracted from oak wood. As the results show, both groups of tannins do not produce any flavan-3-ols after thioacidolysis, but they show specific peaks, which enable determination of their origin. doi:10.5219/202