Tea Extracts as Free Radical Scavengers
A. Gramza1, K. Pawlak-Lemańska2, J.Korczak1, E. Wąsowicz3, M. Rudzinska3
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1 Department of Food Technology and Human Nutrition, Agricultural University, Wojska Polskiego 31, 60-624 Poznań, Poland
2 Department of Instrumental Analysis, University of Economics, Al. Niepodległości 10, 60-967 Poznań, Poland
3 Institute of Food Technology of Plant Origin, Agricultural University, Wojska Polskiego 31, 60-624 Poznań, Poland
Pol. J. Environ. Stud. 2005;14(6):861–867
Antiradical activity was measured with the use of two different methods of scavenging the stable free radicals ABTS and DPPH·. Examined tea extracts showed different antiradical activity. Best activity in scavenging ABTS expressed as TAA (total antioxidant activity) showed black tea aqueous and ethanol extracts. Green tea extracts were four times less effective. Antiradical activity showed that the lowest concentration needed to scavenge the 50% of initial DPPH· radical (EC50) was green and black tea ethanol extracts. Aqueous extracts showed 50% lower activity than equivalent ethanol extracts. Research proved that antiradical activity of plant extracts is dependent on mechanisms of oxidative activity of free radicals used and the chemical structure of contained antioxidants.