Occurrence of n−5 monounsaturated fatty acids in jujube pulp lipids

The pulp lipids of jujube ( Zizyphus jujuba var. inermis ) fruit have been shown by chromatographic, spectrometric and chemical analyses to contain a series of cis ‐monoenoic fatty acids with n−5 unsaturation as major acyl moieties. The total concentration of these n−5 fatty acids, such as 14∶1n−5, 16∶1n−5 and 18∶1n−5, ranged from 22 to 54% of total fatty acids in the pulp lipids of 11 different sources. The main component of the n−5 homologues was 16∶1n−5 in all cases. Other monoenoic acids with n−7 unsaturation, namely palmitoleic ( cis ‐9‐hexadecenoic) acid and cis ‐vaccenic ( cis ‐11‐octadecenoic) acid, as well as with n−9 unsaturation, namely oleic acid, were also identified. In the seed lipids of jujube fruit, none of the n−5 monoenoic acids could be detected. Thus the jujube pulp lipids are characterized by the predominance of n−5 monoenoic acid isomers.