Seasonal variation of essential oil composition of Citrus aurantium l. var. amara

The petitgrain and peel oil isolated by hydrodistillation from leaves and rind of Citrus aurantium L. var amara (Rutaceae) harvested monthly have been studied by GC-FID and GC-MS. Oxygenated monoterpenes were shown to be the predominance fraction (84.5-89.6%) of petitgrain oil and mainly composed of linalool (23.2-32.2%), linalyl acetate (33.2-41.6%), (x-terpineol (7.3-9%), geraniol (4.9-6.4%) and geranyl acetate (4.5-6.4%). On the contrary, oil obtained from peel consisted almost exclusively of monoterpene hydrocarbons, which alone varied from 90.1 to 95.6% of the total oil, with limonene as major oil constituent (87-92.2%). The maximum amount of monoterpene hydrocarbons of petitgrain and peel oil was found at the middle of the productive season (January-February). Whereas petitgrain samples collected in December were found to be relatively rich in oxygen-containing monoterpenes. The highest yield of petitgrain and peel oil was obtained from samples collected in May (0.9%) and January (1.3%) while the lowest was isolated from samples collected in March (0.5%) and February (0.8%) respectively.