Free Radical Scavenging Activity of Herbal Teas of Oenanthe javanica (Blume) D.C.
Shaida Fariza Sulaimana, Seow Eng Menga, Ooi Kheng Leonga, Bahruddin Saadb
aSchool of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.bSchool of Chemistry Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
The free radical scavenging activities of three herbal teas produced from Oenanthe javanica i.e. unfermented, partially fermented and fully fermented teas at three brewing temperatures (4°C, 25°C and 100°C) and different storage times were determined. Hot water (100°C) infusion of unfermented tea indicated the best activity with the lowest EC50 value of 244.28 ± 11.27 µg/ml while EC50 more than 700 µg/ml was obtained from another two processed teas. The antioxidant activities were gradually decreased from the initial stage to 12 months of storage, with obvious reduction in the unfermented tea (nearly 70% reduction). The results strongly revealed the influence of tea processing procedures, brewing temperatures and storage times on the antioxidant activities of the processed herbal teas.
Keywords: Oenanthe javanica, team, herbal, antioxidant