The in vitro antioxidant activity of different types of palm dates (Phoenix dactylifera) syrups

Palm date fruits have been used for nutritional and medicinal purposes in Middle Eastern countries. They are used in folk medicine for treatment of liver diseases and highly recommended to be consumed by pregnant women before and after delivery. Therefore, the present work aimed to determine the total phenolic content and total flavonoids in three syrups obtained from palm dates extracted with aqueous ethanol (80%) and to evaluate in vitro their antioxidative properties. The new findings showed that the three tested syrups contained significantly different amounts of both total phenolic content and total flavonoids. Syrups can be arranged according to the increase of total phenolic contents and total flavonoids as follows: Yemeni-Rotab > Saudi-Tamr > Iraqi-Tamr. The results of antioxidant activities of palm dates syrups obtained by using different in vitro methods were varied depending on the method used. According to the TBARS method, H₂O₂ scavenging ability and DPPH methods, all syrups showed to have high to very high antioxidant activities. On the other hand, syrups showed low to intermediate antioxidant activities when other methods were used, such as the scavenging ability of OH and NO and the ability to chelate Fe²⁺ ions. Generally, the values of antioxidant activities of Rotab-syrup have been shown to be always the highest.