Comparative chemical composition and antioxidant capacity of essential oil and oleoresin from Eucalyptus globulus Labill. leaves

Abstract

The Eucalyptus globulus is a tree which is cultivated in Peru for its wood, while its leaves are often discarded. This study compared the extraction yield, chemical composition, and antioxidant capacity of essential oil and oleoresin obtained from the leaves. The essential oil was extracted by hydrodistillation (1.62 % yield), and oleoresins were obtained using supercritical CO2, with and without ethanol as a co-solvent (yield up to 8.96 %). GC-MS analysis identified 1,8-cineole as the major compound in the essential oil and in the oleoresin extracted with supercritical CO2+ethanol. The essential oil showed a higher monoterpene content (80.33 %), while the oleoresins were richer in sesquiterpenes (up to 63.68 %). The total phenolic content was significantly higher in the oleoresin (5.05-11.30 mg GAE/g) than in the essential oil (0.25 mg GAE/g). Antioxidant capacity was also significantly higher in the oleoresins. These findings highlight the potential of E. globulus oleoresin as a natural antioxidant for food and pharmaceutical applications.