Antioxidant activity determination in Sencha and Gun Powder green tea extracts with the application of voltammetry and UV-VIS spectrophotometry

This article presents the electrochemical analysis of the oxidation of rutin and green tea extract solutions and the antioxidative properties of these substances. Flavonoids and other polyphenols contained in green tea have antioxidative properties due to the presence of various numbers of hydroxyl groups in different arrangements. The investigation of the oxidation of green tea extracts was performed to identify the most effective antioxidant. The cyclic and pulse voltammograms show that the extract of Gun Powder (GP) green tea contained rutin and other polyphenols, while the extract of Sencha (S) tea contained other antioxidants that are oxidised at a more positive potential. The GP extract showed slightly better antioxidative properties than did the S extract. The UV-VIS spectra show that, in addition to flavonoids extracts contain chlorophyll. The results obtained demonstrate that the tested tea extracts show very good antioxidative properties and therefore may be considered as potential stabilising agents that are able to reduce the rate of undesirable oxidation processes. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.