Extraction of Phenolic Compounds of six Algerian date (Phoenix dactylifera L.) cultivars from Ain-Saleh region, using Reflux method and Screening of Antioxidant Activity in vitro

This study was designed to evaluate the antioxidant activity of phenolic compounds for six cultivars of date from In Saleh region (Phoenix dactylifera L.), which were extracted by reflux with solvents, 80% methanol and 70% aceton after the phenolic and flavonoid content were estimated. The total phenolic content (TPC) and total flavonoid content (TFC) of the extracts were measured using Folin-Ciocalteau and aluminum chloride colorimetric methods, respectively. Antioxidant activity acetone/H2O and methanol/H2O extracts using ABTS, DPPH, FRAP, TAC and CUPRAC assays. The results showed that methanolic solvent reflux gives better yields. The highest level of phenolic compounds for all dates varieties was found in the 80% methanol extract. This level ranged from 8.04 ± 0.14 to 46.81 ± 1.22 mg GAE/100 g fresh weight and flavonoid content was observed relatively low for both two solvents. However, extraction into 70% acetone gave the highest antioxidant activity with all assay. These results showed that dates had strongly scavenging activity on DPPH reaching 3.12 μg/mL in methanol/H2O from Cul1 (6.9 μg/mL with ascorbic acid), also on ABTS reaching 6.51 μg/mL in acetone/H2O from Cul2 (104.98 μg/mL with ascorbic acid).