Fig. 5
a Principle component analysis of the absolute intensities for all peaks (m/z of 45 to 299) of mass spectra of the headspace volatiles of seven jujube species from five provinces. Each point represents one sample; a total of 35 samples are included. b Principle component analysis of the quantitative results of acetic acid, ethyl acetate, ethyl caproate, octylacetate, damascone of the headspace volatiles of seven jujube samples. Each sample was measured three times. Detailed information of sample A to G: A. Jun Jujube (Akesu, Xinjiang); B. Yuan Jujunbe (Ningyang, Shandong); C. Hui Jujube (Qiangruo, Xinjiang); D. Po Jujube (Xingtang, Hebei); E. Goutou Jujube (Qingjian, Shanxi); F. Chang Jujube (Zaozhuang, Shandong); G. Yuan Jujube (Ningyang, Shandong)