Different estimation methods of tannins-proanthocyanidins or hexahydroxydiphenoyl esters-have been compared and applied to polyphenols of various wood extracts. In the case of proanthocyanidins, reaction with vanillin in the presence of sulfuric acid is more sensitive than estimation by anthocyanidin formation. It is more specific than the assay by formaldehyde precipitation. Reaction with nitrous acid affords a selective estimation of hexahydroxydiphenoyl esters. These methods are applied to tannin estimation in wood extracts of 5 gymnosperms and 12 angiosperms and the values obtained compared to total phenols amounts.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below