Total phenolic and flavonoid contents and antioxidant activities of sixteen commercial date cultivars grown in Saudi Arabia

Abstract

The total phenolic and flavonoid contents and flavonoids/phenolics% of sixteen commercial Saudi date cultivars at the Tamer stage were measured. The antioxidant activities of dates using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were investigated. A strong correlation was existed between antioxidant activity and phenolic concentration of the date cultivars. Date cultivars had different phenolic and flavonoid patterns and exhibited also different antioxidant capacities. All of the tested cultivars were growing in the same district (Al-madinah Al-Munawwarah), accordingly the observed variations are mainly due to the genetically factor. The results concluded that flavonoid compounds were more sensitive toward DPPH assay than ABTS assay. The correlation of the IC₅₀ between DPPH and ABTS radical scavenging were evaluated. The ABTS assay was more sensitive toward phenolic compounds than DPPH assay for the most tested date cultivars, except of the phenolic compounds of cv. Agwah and cv. Safawi had the same sensitivity toward DPPH and ABTS assays. The results confirmed the antioxidant potential of the most commercial Saudi date cultivars.