Abstract

This study shows that Ehrlich’s reagent is specific for the colorimetric analysis of catechins and condensed tannins without any interferences from hydrolysable tannins and other biogenetically related flavonoid compounds.

A standard calibration curve was established for the quantitative estimation of (+ ) — catechin over a concentration range of 50—500 ,g/m1. The colour reaction is useful for distinguishing between condensed tannins based on catechins and other fiavan-3-ols. A comprehensive literature survey precedes the experimental section.