Phenolic compounds and its antioxidant activities in ethanolic extracts from seven cultivars of Chinese jujube

Phenolic compounds and its antioxidant activity of extracts from seven cultivars of Chinese jujubes were investigated by high performance liquid chromatography (HPLC) with standards and different antioxidant evaluation methods, such as phosphomolybdenum assay, superoxide radical scavenging activity (SRSA), hydroxyl radical scavenging activity (HRSA), antihemolytic activity and inhibition of lipid peroxidation in rat liver homogenate, respectively. The results showed the components of the extracts are comprised of total phenols and flavonoids, and its content ranges from 454.3 to 1298.9 (GAE mg/100 g dry weight). Phlorizin, catechin, gallic acid, chlorogenic acid, caffeic acid were the predominant phenolic compounds. All the extracts had significant antioxidant activities either in vitro or in vivo. Correlation analysis indicated that the antioxidant capacities of Chinese jujube extracts demonstrated a good positive relationship with some phenolic acids, which was higher in Xiao and Goutou. The results indicated that Xiao and Goutou could be attributed to a potential source of natural antioxidants for food applications.