COMPARISON OF ANTIOXIDANT ACTIVITY AND PHENOLIC CONTENT OF THREE VARIETIES OF ALGERIAN DATES

Abstract

The date palm is a typical plant of the arid and semi arid areas. Unfortunately, not all of its varieties profits from an economic interest except Deglet-Nour. This poses a danger to date palm genetic inheritance and the biodiversity. This study was initiated to investigate the antioxidant of methanol-water extracts from three date palm fruits (DPF) common in the region of Ouargla (Algeria); Degla Baidha (DB), Tamjhourt (Tam) and Tafezauine(Taf). The antioxidant capacities of these varieties were evaluated by using different methods, namely ABTS.+(2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid)) scavenging activity expressed as Trolox equivalent antioxidant capacity (TEAC), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, Reducing power expressed as Ascorbic acid equivalents antioxidant capacity (AEAC). Total phenol content (TPC) was determined by using Folin–Ciocalteau Reagent. Total flavonoid content (TFC) was determined by using aluminum chloride method. Concerning the ABTS scavenging activity (Trolox equivalent), the TEAC values decreased in the order of DB>Tam>Tef. Effective scavenging concentration (IC50) on DPPH radical decreased in the order of Tam>DB>Tef. Effectiveness in reducing power was in a descending order of Tam>DB>Tef. The TPC was found from 41.8 to 84.73 mg/100g gallic acid equivalents. The order of TPC of DPF is: DB>Tef>Tam, while TFC varied between 7.52 to 14.1 mg/100g rutin equivalents and in a descending order of DB>Tam >Tef. These results suggest that all date varieties serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient.