Evaluation of antioxidant capacity by cyclic voltammetry of Phoenix dactylifera L. (date palm)

In this study we used spectrophotometrical techniques to estimate antioxidant efficacy by using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging capacity and reducing power capacity. We have used also electrochemical techniques performed by cyclic voltammetry. The present study examined the antioxidant activities of the methanolic extract (ME) of date palm (Phoenix dactylifera. L) fruits (DPF) of four native cultivars from Algeria, namely, Ghars (Gh), Chtaya (Cht), Degla Beida (DB) and Tinissine (Tns). Quantitative estimation of total phenol and flavonoid content by a colorimetric assay showed that methanol extracts are rich in these components. The content of total phenolics of different cultivars extracts was in the range of 26.083 - 35.850 GAE/100g DW. while it was the content of total flavonoids of the different cultivars extracts was in the range of 5.276 - 6.055 QE/100g DW. The value of IC₅₀ for DPPH radical test ranged from 0.193 to 0.400mg/ml. All extracts showed very good activity of ferric reducing power, the higher power was in methanolic extract of Tns. The less IC₅₀ value in cyclic voltammetry method (CV), which meet the highest effective antioxidant was 0.121 mg/ml in methanolic extract of Tns.