Comparative chemical composition of direct, recovered and combined essential oils of Lavandula angustifolia Mill

摘要

Lavender is one of the important aromatic plants widely used in perfumery, flavour industries and as a relaxant in aromatherapy. Experiments were conducted with pilot scale distillation unit to compare the variations in chemical composition of direct (obtained direcdy by distilling shoot biomass of the crop), recovered (obtained by redistilling hydrosol) and combined oils (obtained by mixing direct and recovered oils) produced through steam distillation of Lavandula angustifolia Mill., cultivated in the western Himalayas. The samples were analyzed by GC and GC-MS. The direct and combined oils were richer in linalool (28.8 and 31%), linalyl acetate (35.3 and 32.2%) and lavandulyl acetate (1.8 and 1.7%). The recovered oil was richer in linalool (54.7%) anda -terpineol (23.4%). The higher concentration of linalool and α-terpineol in the redistilled oil makes it an alternate source for these constituents for commercial utilisation. Higher content of monoterpene hydrocarbons (10.1%), sesquiterpene hydrocarbons (9.4%) and esters (41.3%) were detected in direct oil followed by combined oil (9.2, 8.9 and 37.7, respectively). Higher alcohol content (87.9%) was recorded in recovered oil, followed by combined oil (39.9) and direct oil (35.7). In addition, the recovered oil contained higher content of monoterpene cyclic ethers (4.3%) and lower content of esters (0.4%) and monoterpene hydrocarbons (0.9%).