Determination of antioxidant properties of fig fruit extracts (Ficus carica L.)

Abstract

The fig tree (Ficus carica L.; Moraceae) is very common in the Mediterranean and in countries with dry and warm-temperate climates. Since ancient times figs have been used only for human consumption. Their nutritive and pharmacological properties have been investigated recently. Their consumption helps in the prevention of artery blockage, high fiber content has laxative effects, and the fig latex inhibits the growth of carcinoma cells. The aim of this study was to determine the content of some active components contained in extracts of five different fig cultivars ('Šaraguja', 'Termenjača', 'Crnica', 'Bjelica' and 'Bružetka bijela'). Fruit samples were freeze-dried. Extracts of total phenols and flavonoids were obtained by extraction in 70% methanol or 70% ethanol. For determination of antioxidant activity, scavenging capacity on DPPHß radicals and reducing power were performed. By high performance liquid chromatography (HPLC) some antioxidant compounds were detected and quantified. Total phenolics content in F. carica extracts was from 7.24 to 11.17 mg CAE/g of dry extract. All methanolic extracts showed higher content of total phenols. The DPPH radical scavenging capacity was found to exhibit IC50 value for the extract concentration lower than 0.40 mg/ml for extract cultivars 'Crnica', while for others this capacity was higher than 0.60 mg/ml. Using the reducing power antioxidant test, higher antioxidant activity was determined for 'Bjelica' than in all other extracts. Results obtained by the reducing power method were compared to activity of ascorbic acid, standard antioxidant compound.