Abstract:

The main sugars and organic acid components in fruits of 20 Chinese jujube varieties of different development stages were determined to compare the difference among varieties and reveal the dynamic changes. The result indicated that major components of sugars in Chinese jujube fruits were sucrose，fructose and glucose，and the sucrose content was the highest，followed by fructose and glucose，it was sucrose accumulation type. Total sugar and each component contents had significant differences in different cultivars’ fruits.‘Xinzheng Huizao’had the highest content of total sugar. With the development of the fruits，fructose，glucose and sucrose contents were accumulated constantly. At the early stage of the fruit development，fructose and glucose were main；while sucrose was main after white period. The major components of organic acid in Chinese jujube fruits were malic acid，quinic acid and succinic acid，and the malic acid content was the highest，so the malic acid was main. Total acid and each components content were significantly different among varieties. The total acid content of‘Binxian Jinzao’was the highest. Total acid，malic acid，quinic acid and tartaric acid contents were going up slightly along with the development of fruits，and citric acid content had no significant difference during different development stages. Succinic acid content was low in white period，which had extremely significant difference with crisp ripe and full ripeness. The sugars and organic acids correlation analysis showed that the total acid and malic acid，quinic acid；total sugar and sucrose，fructose，glucose；malic acid and total sugar，sucrose had very significant positive correlation. The citric acid and fructose sugar，glucose had significant negative correlation. The total acid and fructose，tartaric acid and ursolic acid had significant positive correlation.

Key words: Chinese jujube, variety, development stage, soluble sugars；organic acids