Influence of the extraction solvent on antioxidant capacity and total phenolic in currant fruits

In black and red currant fruits the phenolic content and antioxidant capacity were determined. Two solvent systems (methanol and ethanol) at different concentrations and two methods of extraction were used. The study was conducted using fruits of black currant and red currant for determinations. The total phenolics content of each extract was measured according to the Folin-Ciocalteu method. The anti-oxidant capacity of the fruit extracts was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. It was found that the efficiency of the solvents used for the extraction of polyphenols varied substantially. The total phenolic content was 0.88 to 4.6 gallic acid equivalents in milligrams per gram of fresh weight (mg GAE /g FW). The content of phenolics was highly cor-related with the anti-oxidant capacity (r = 0.97- 0.98) and extracts obtained using ethanol solvents were more effective radical scaveng-ing activities than the ones obtained using methanol solvents. Fruits of red and black currant represent an abundant source of phenolics, and prove to have good anti-oxidant capacity. Abbreviations: DPPH: 2,2-diphenyl-1-picrylhydrazyl; GAE: gal-lic acid equivalents; TPC: total phenolics contents; TEAC: Trolox equivalent antioxidant capacity