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Publications in Scientific Journals:

G. Kroyer:
"Evaluation of antioxidant properties of plant extracts";
Annals of Nutrition & Metabolism, 52 (2008), 118.



English abstract:
EVALUATION OF ANTIOXIDANT PROPERTIES OF PLANT EXTRACTS

G. Kroyer
Institute of Chemical Engineering, Natural Products and Food Chemistry, University of Technology, Vienna, Austria.

Recent research in food science have focused on plant food components which act as antioxidants and free radical scavengers. In this regard, the content of total polyphenols in commonly consumed herbal teas and the evaluation of their potential antioxidant properties might be of great significance.
Water extracts of the herbal teas rooibos tea, maté tea, peppermint tea, mallow tea and chamomile tea were prepared according to practical usage. Total polyphenols were analyzed according to the Folin-Ciocalteu method. The antioxidant and radical scavenging capacity was evaluated by the DPPH radical scavenging method (EC50, ARP).
All the herbal tea extracts showed considerable amounts of polyphenols (mg/g) with the highest content in rooibos tea (315) followed by maté tea (151), peppermint tea (93), mallow tea (52) and chamomile tea (50). Correspondingly, remarkable anti-radical power (ARP) was observed in the herbal tea extracts in the order rooibos tea (138) > maté tea (113) > peppermint tea (118) > chamomile tea (19) > mallow tea (12).
Acording to this study herbal tea consumption would be helpful in maintaining and promoting health. Furthermore, herbal tea extracts could be regarded as effective natural antioxidant additives for food products and as functional dietary food supplements.

Keywords:
herbal tea, polyphenols, antioxidant activity


Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_168973.doc


Created from the Publication Database of the Vienna University of Technology.