DETERMINATION OF TOTAL PHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF AQUEOUS EXTRACTS OF SELECTED MEDICINAL PLANTS
UDK: 633.88:547.56 This study aimed to analyse and compare the total phenolic content and the antioxidant activity of aqueous extracts of three medicinal plants: hibiscus (Hibiscus spp.), rosemary (Rosmarinus spp.) and savory (Satureja spp.). The plant extracts were prepared using maceration process. The total phenolic content was determined spectrophotometrically with the Folin-Ciocalteu reagent using gallic acid as a standard and the antioxidant activity was analysed using the Briggs-Rauscher reaction method. The inhibition times produced by plant extracts on an active Briggs-Rauscher oscillating reaction mixture were recorded potentiometrically. The total phenolic content was found 0.27, 1.29 and 1.43 mgGAE/g of dry extract for hibiscus, rosemary, and savory, respectively. Good correlation was found between the total phenolic content and the Briggs-Rauscher inhibition times (R2 = 0.994).