ANTIOXIDANT ACTIVITY AND POLYPHENOLS CONTENT OF SOME HERBAL TEAS OF LAMIACEAE FAMILY FROM GREECE AND BULGARIA

摘要

Ten medicinal plants of the Lamiaceae family grown in Greece and Bulgaria and used for preparation of herbal teas were studied for their polyphenols content and antioxidant activity. Total phenols (TIP), ftavonoid phenols (FP), nonfiavonoid phenols (NFP) and flavan-3-ols (F-3-ols) varied in wide ranges within 750-1355, 524-920, 285-385 and 67.4-110.3 mu g CE/mg%, respectively. Antiradical activity evaluated by DPPH ranged from 6.05 to 9.95 mu mol Trolox/g dw and by ABTS - from 13.07 to 18.30 mu mol Trolox/g dw. The ferric reducing power of the studied aqueous extracts ranged from 6.49 to 8.76 mu mol TRAP/g dw and from 3.37 to 4.93 mu mol AAE/ g dw. The aqueous extract of oregano is distinguished by the highest content of polyphenols and the highest antioxidant activity and that of basil - by the lowest. A high correlation was established between the TP content and the antiradical and ferric reducing power capacity of the aqueous extracts. The high free-radical scavenging potential of the herbal teas on the basis of the studied plants are discussed in view of their use as important dietary sources of antioxidant phenolics.