Characterization of volatile compounds in Ylang-Ylang essential oils from Comoros and Madagascar by gas chromatography and principal component analysis

Chemical composition of ylang-ylang essential oil is affected by the geographical origins of flowers used for extraction. This study aimed to determine the compositional difference between the extra, first and third grades of ylang-ylang essential oil from Comoro Islands and Madagascar. The oils were characterized by both gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) in conjunction with principal component analysis (PCA). A total of 124 volatile compounds were identified and quantified by GC-MS and GC-FID. Twenty-two compounds that made up 85% to 90% of the oils were shortlisted to compare across grades and geographical origins. The PCA showed that the ylang-ylang essential oils are clustered according to grade and origin based on their compositions. Analysis of variance was performed to determine the statistical significance of the differences between each compound across extra, first and third grades of ylang-ylang essential oil from Madagascar and Comoros. The oils of Madagascar are dominating in geranyl acetate, cis-alpha-farnesene, benzyl benzoate, humulene and caryophyllene, while in those of Comoros, cinnamyl acetate, benzyl salicylate, trans-farnesyl acetate and alpha-farnesene are found to be higher. It is possible to verify the origin and grade of an unspecified source of ylang-ylang essential oil from the biplot of the 22 compounds.