The Antioxidative Activity of Aqueous and Ethanolic Extracts of Rosemary and Green Tea Leaves: A Comparative Study

The antioxidant activities of rosemary and green tea leaves, aqueous and ethanolic extracts, have been studied by using two different methods (reducing power and chelating ability). It was found that the total phenolic compounds in aqueous and ethanolic extracts of rosemary and green tea leaves were 13.44, 18.75, 39.38 and 48.44 mg/ 100 mg dry extract respectively. The flavonoids (which is a part of the phenolic compounds) were found to be 9.54, 12.65, 17.69 and 22.70 mg/ 100 mg dry extract in aqueous and ethanolic extract of rosemary and green tea leaves respectively. The ethanolic extract shows high content of phenolic compounds and in turn highly antioxidative activity for both rosemary and green tea leaves as compared with aqueous extract. The aqueous and ethanolic extracts of rosemary and green tea leaves show high reducing power ability comparing with their abilities as chelating agents. Although, the phenolic compounds of green tea leave almost about 3-fold as compared with rosemary leave in both aqueous and ethanolic extracts, their extracts show extremely the same mode of action in both methods of determination (the reducing power and chelating ability). Therefore, we are fully recommended the rosemary leave extracts as a potent food preservative.