Abstract

SENSITIVITY OF AOAC AND FOLIN’S METHOD IN ESTIMATION OF TANNINS FROM DIFFERENT PLANTS

Mondal Manoshree and Chachad Devangi*

Abstract

Tannins are a collective term for a variety of plant polyphenols used in the tanning of rawhides to produce leather. They are widely distributed in plants and occur in especially high amounts in the bark of certain trees and galls. Detection and estimation of tannins present in any plant product to be used as medicine becomes one of the preliminary tests for deciding the medicinal value of the plant part. For this study, the total tannin content was estimated in terms of standard tannic acid since it is one of the most common forms of tannins. The selected samples studied were fresh and dried Vitis vinifera, fresh and dried Phyllanthus emblica powder, fresh and dried Piper nigrum fruits, dried Cinnamomum zeylanicum, dried Elattaria cardamomum, dried Aloe barbadensis powder and Mangifera indica bark. Two different estimation methods were carried out for each of the aqueous and alcoholic extracts of the samples. First method is the regularly and extensively used Folin’s method for test of polyphenols. Second method is the lesser known AOAC (KMnO4) method.

Keywords: tannins, estimation of tannins, Folin-Ciocalteau reagent, KMnO4 method, AOAC method, Vitis vinifera, Phyllanthus emblica, Piper nigrum, Cinnamomum zeylanicum, Elattaria cardamomum, Aloe barbadensis, Mangifera indica.