Abstract: The effects of natural drying and hot-air drying on the composition of phenolic compounds in jujube and their antioxidant activity were investigated. The contents of total phenolics, total flavonoids and procyanidins, DPPH radical scavenging capacity and total antioxidant capacity were determined in dried jujube. The results showed that the content of phenolic acids revealed a significant decrease in dried jujube; no obvious change in the content of total flavonoids was observed during the drying of jujube; however, the content of procyanidins exhibited a significant increase after drying. The antioxidant activity of jujube was not correlated with the contents of total flavonoids or procyanidins, but highly correlated with the content of phenolic acids. In addition, hot-air drying and natural drying did not result in an obvious difference in the antioxidant activity of jujube. Due to the advantages of shorter drying time and dried products with strong aroma, hot-air drying is a recommended drying style for jujube.

Key words: jujube, phenolic compounds, antioxidant activity, drying style