Ascorbic acid and tannins from Emblica officinalis Gaertn. Fruits--a revisit

Abstract

The fruits of Emblica officinalis Gaertn. (Euphorbiaceae), also known as amla in Ayurveda, are considered to be a rich source of ascorbic acid. However, the antioxidant activities exhibited by E. officinalis extract are superior to those of ascorbic acid itself. Low molecular hydrolyzable tannins emblicanins A and B have been suggested in the earlier literature to be the contributory antioxidant molecules in the extract. This work finds no evidence for the presence of emblicanins A and B in the extract. In addition, the high content of ascorbic acid is also questionable due to previous nonidentification of coeluting mucic acid gallates. This paper reports a new HPLC method to detect even trace amounts of ascorbic acid in E. officinalis fruit juice or extract.