Increasing attention has been paid to the nutritional values and pharmacological effects of Ziziphus jujuba. Therefore, in this study, four phenolic and flavonoid fractions of 16 jujube cultivars from different geographic regions of China were separated and quantified. In addition, the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH·) scavenging method and the ferric reducing antioxidant power (FRAP) assay. The total phenols and flavonoids contents ranged from 253.4 to 494.9 mg GAE/100 g and 125.3 to 425.4 mg rutin/100 g, respectively. Subsquently, a total of 10 phenolic acids and two flavonoids were identified, and most quantified phenolic acids with antioxidant activity were mainly present in the glycosided and insoluble-bound phenolic fractions. The results of this study indicate that some jujube cultivars, especially Zanghuang Z. jujuba, Leling Z. jujuba, and Jiaxian Z. jujuba could be selected to promote a healthy diet due to their more plentiful nutritional and phytochemical beneficial effects.
Keywords: Antioxidant activity; Flavonoids; Jujube; Polyphenols.