EFFECT OF EXTRACTION SOLVENT TO TOTAL POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF GUAVA LEAF EXTRACT

Abstract

This study investigated the effect of extraction solvent on total polyphenol content and antioxidant activity of Queen guava leaf extract. The leaves were collected in Bac Lieu province, washed, dried and ground to obtain powder as raw material. Two types of solvents, namely ethanol and methanol, were used to extract by maceration method. The obtained products were determined extraction efficiency and total polyphenol content. The results showed that methanol extract acquired higher extraction efficiency and polyphenol content compared to ethanol extract. Methanol extract was selected for the investigation of fraction extracts in three solvents with different polarities: n-hexane, dichloromethane (DC) and ethyl acetate (EA). The antioxidant activity of methanol, n-hexane, DC and EA extracts was identified by DPPH and ABTS assays. The antioxidant activity of total methanol and EA extracts were the best with EC₅₀ values of 15.39 and 12.49 µg/mL, respectively. These results facilitate selecting suitable solvent in developing natural antioxidant products from Queen guava leaf.