COMPARATIVE-STUDY OF COLOMBIAN CITRUS OILS BY HIGH-RESOLUTION GAS-CHROMATOGRAPHY AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Essential oils from fruit peel and leaves of colombian lemon (Citrus v olkameriana), mandarin (C. reticulata) and orange (C. sinensis) were o btained by steam distillation and/or cold pressing. The extracts were analysed by high-resolution gas chromatography using either a flame io nization detector or a mass selective detector (electron impact ioniza tion, 70 eV). The oil constituents were identified according to their mass spectra and Kovats retention indices determined on both polar and non-polar stationary phase capillary columns. The concentration of vo latile secondary metabolites was maximum when the citrus fruits were a t an intermediate maturation stage characterized by a greenish yellow coloration (45-75% green). While citrus peel oils contained from 94.01 to 98.66% of monoterpenes (C10H16), limonene as a major component and from 0.82 to 5.84% of oxygenated compounds, the extracts from citrus leaves contained only 65.26, 31.23 and 79.43% of monoterpenes (C10H16) in lemon, mandarin and orange, respectively. Oxygenated compounds in these-oils represented 33.08, 68.47 and 16.38%, respectively.