The comparison of the antioxidant activity of extracts and lyophilised samples of blackcurrant (Ribes nigrum L.)

The current research is focused on natural antioxidants and their positive biological effects. A major source of natural antioxidants is dark coloured fruits. The antioxidant activity was determined in extracts and lyophilised samples of blackcurrant. In this study, ethanol extracts (purified and non-purified) and lyophilised samples of extracts (purified and non-purified) were screened for antioxidant properties. Radical scavenging activity was determined spectrophotometrically (lambda=517 nm) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The percentage of scavenging activity was expressed as the percentage of inhibition of DPPH activity. A non-purified ethanol extract of blackcurrant showed good antiradical activity in scavenging DPPH radical with an average inhibition of 35.36%, purified ethanol extract of blackcurrant showed higher antiradical activity with an average inhibition of 65.40%. The non-purified lyophilised samples of blackcurrant showed an average inhibition of 31.89% and the purified lyophilised samples exhibited a higher average inhibition of 64.56%. In this research it was found that these extracts have remarkable antioxidant activities. Purified lyophilised samples and purified ethanol extracts seem to be more concentrated in active substances content as a result of removing inert constituents from the extract matrix. The isolation and lyophilisation procedure used in this study can be considered as gentle enough for retaining of antioxidant properties in examined samples.