Physicochemical properties and antioxidant activity of Yulingdang jujube (Ziziphus jujuba Mill.) fruit at different stages of maturity

Ziziphus jujuba cv. Yulingdang (YLD) is a jujube cultivar that has been approved as a new plant cultivar by the State Forestry Administration of China. The physicochemical properties and antioxidant activity of YLD fruit were evaluated at seven stages of maturation, ranging from fruit setting to red ripe. The antioxidant activity of YLD fruit was assessed through total phenolics, total flavonoids, and methods including the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging rate, β-carotene-linoleic acid emulsification method, and reducing power. These measures were observed to decrease gradually as maturation progressed. The study also indicated an increase in total sugar and total acid levels, along with a decrease in moisture, soluble protein, and the sugar-acid ratio during maturation. Understanding this information is essential to fully exploit the commercial potential of YLD fruit.