Comparison of volatile compositions of 15 different varieties of Chinese jujube (Ziziphus jujuba Mill.).

Jujube (Ziziphus jujuba Mill.) extract has been commonly used as a flavoring ingredient due to its unique aroma. In this study, solid phase micro extraction method was used to extract the volatile compounds in fresh jujube, with the aid of GC-MS for further chemical separation and identification. As a result, 33 volatile compounds, including aldehydes, alcohols, acids, ketones and esters, were identified. Among them, hexanal (276.5-1314 μg/100 g FW), (E)-2-hexanal, (145.1-1876 μg/100 g FW), nonanal (188.2-1047 μg/100 g FW), and n-decanoic acid (58.42-1268 μg/100 g FW) were found to be the major volatile compounds in fresh jujube fruit. Based on the type and amounts of the volatile compounds, 15 Chinese jujube cultivars were divided into 5 clusters through hierarchical cluster analysis and principal component analysis (PCA). Fiver clusters include cluster 1 (LB, HP, LZ, NP, JS, PZ, and YL), cluster 2 (BJ, DB), cluster 3 (PB, BZ, JD and XZ), cluster 4 (JB) and cluster 5 (YZ). According to the PCA, the clusters 1, 2 and 3 could not be discriminated from each other, but clusters 4 and 5 could be separated very well from each other.