Sesquiterpene hydrocarbons of cold-pressed lime oils

The sesquiterpene hydrocarbon composition of cold-pressed lime oils of the Key lime (type A and B) and the Persian lime varieties were investigated, a lpha -Santalene, gamma -curcumene, beta -selinene, beta -sesquiphellandrene and 7-epi-alpha -selinene were confirmed as so far unknown trace constitue nts of cold-pressed lime oils. The usage of unusually gentle GC conditions permitted the establishment of germacrenes A and C, both thermally and chem ically sensitive compounds, as important constituents of cold-pressed lime oil for the first time. This allowed to demonstrate that the germacrenes A, B, C and D make up ca 25% of the sesquiterpene fraction in expressed Key l ime oil. Usage of conventional GC conditions largely lead to the destructio n of these heat-labile compounds, which may be of organoleptic importance. The employed detection method also allowed the identification of germacrene -A. in Chinese citronella oil. Copyright (C) 2000 John Wiley & Sons, Ltd.