VOLATILES OF AVOCADO FRUIT

Volatile constituents of avocado mesocarp were isolated by concurrent steam distillation/solvent extraction in the Likens-Nickerson apparatu s using pentane-ether as solvent. The extracts which resulted were con centrated in a Kuderna-Danish concentrator and analysed using gas chro matography and linked gas chromatography-mass spectroscopy (GC-MS) emp loying capillary columns of contrasting polarity. Hydrocarbons (mainly sesquiterpenes) and alkanals were the predominant constituents presen t. In the immediate extract of the avocado mesocarp, beta-caryophyllen e (60%) was the main sesquiterpene, followed by alpha-humulene (5.9%), caryophyllene oxide (4.8%), alpha-copaene (4.5%) and alpha-cubebene a s the main hydrocarbons; alkanals were present, but only in low concen trations. In the extract prepared following storage (2 h) of the mesoc arp at room temperature, beta-caryophylene (28.8%) was the main sesqui terpene, followed by alpha-copaene (10.7%), a cadinene isomer (8.5%), alpha- and beta-cubebene (7.7%), alpha-farnesene (5.3%) and octane (4. 8%) as principal hydrocarbons; decenal (6.3%) and heptenal (3.2%) were the main aldehydes. (C) 1998 Elsevier Science Ltd. All rights reserve d.