ANALYSIS OF THE VARIATION OF THE ESSENTIAL OIL COMPOSITION OF EUCALYPTUS-GLOBULUS LABILL FROM PORTUGAL USING MULTIVARIATE STATISTICAL-ANALYSIS

Samples of Eucalyptus globulus Labill. subsp. globulus essential oil o btained from trees of different ages, growing in maritime and inland p ortuguese regions, collected in May and November periods (1991-1992), were submitted to quantitative analysis. The results obtained were int erpreted using principal component analysis and cluster analysis, cons idering the 25 abundantly found compounds. These compounds were groupe d according to their variation patterns, leading to the definition of five groups, four of which have shown to be significant in the differe ntiation of young and adult leaves. Young leaves, when compared to adu lt leaves, were found to have higher oil yields, with lower percentage of group II (in which 1,8-cineole is included) and III compounds and higher percentages of compounds from groups I and IV. Variations in th e oil composition due to season and geographic localisation were found not to be significant. (C) 1997 Elsevier Science B.V.