EVALUATION OF THE ANTIOXIDANT CAPACITY OF HERBAL TEAS BY A PROCEDURE BASED ON THE BLEACHING OF ABTS RADICAL CATIONS

The antioxidant capacity of herbal teas is evaluated by a new procedur e based on the bleaching of the absorbance of pre-formed 2,2'-azinobis (3-ethylbenzthiazolinesulfonic acid) radical cations. The method allow s both an estimation of the total amount and the reactivity of the ant ioxidants present in the infusion. The species evaluated were black te a, Matricaria chamonilla L., Peumus boldus Mel., Buddleja globosa Hope , Mentha sp., Mentha piperita L., Melissa officinalis L., Plantago maj or L., Aloysia citriodera Ort. and Rosa moschata Herrm. All the infusi ons were prepared employing commercial teabags and, for some herbals, the results were compared with those obtained employing the correspond ing green leaves. Although all the herbal teas present significant ant ioxidant activities, the quantities and qualities of the antioxidants vary markedly between the different infusions.