Chemical Identifications of Citrus Peels Essential Oils

Due to the importance of essential oils and their use in various industries, the essential oils of four types of citrus consisting of orange (C. sinesis), tangerine (C. reticulate), sweet lemon (C. limetta) and sour lemon (C. limon) were extracted and subjected to chemical analysis to identify and evaluate the chemical constituents of the oils. The average essential oils of orange, tangerine, sweet lemon and sour lemon peels were 1.48%, 0.90%, 0/54% and 0.46% (w/w) respectively. Seven compounds were identified in the orange peel essential oil where limonene (64.87%) followed by N-methyl-D3-aziridine (10.78%), cytidine (8.55%) and propane, 1,1, - oxybis (4.99) were the major components. Seventeen compounds were identified in tangerine peel essential oil where the main components were limonene (28.10%), xanthotoxin (18.40%), cytidine (8.34%) and 1,4-diethynylcyclobutene (4.73%). Eighteen compounds were identified in the essential oil of sweet lemon peel where limonene (49.79%), xanthotoxin (12.62%), 6,6-dideutero-nonen-1-ol-3 (10.20%) and 4-vinyl- 2-methoxy-phenol (5.20%) were the major components. Seven compounds consisting of limonene (83.03%), cytidine (4.16%), N-methyl-D3-aziridine (4.42%), 4- vinyl-2-methoxy-phenol (2.79%) were the major constituents of sour lemon peel essential oil in respective decreasing order. Limonene was the predominant compound in all the citrus fruit peels and showed the highest concentration of this compound among the samples examined.