Leaf extracts of Eucalyptus have been approved as food additives,and the extracts are also currently used in cosmetic formulations. Recently, attention has been focused on the functional properties of these extracts. Research has shown that the extracts exhibit various biological effects, such as antibacterial, antihyperglycemic
and antioxidant activities (Takahashi, Kokubo, & Sakaino, 2004), with essential oils playing a central role in these biological functions. Essential oils are the odorous, volatile products of the secondary metabolism of an aromatic plant, which are often concentrated in a particular organ of the plant such as leaves, stems, bark or fruit (Conner, 1993). An estimated 3000 essential oils are known, of which about 300 are commercially important, destined chiefly for the flavours and fragrances market (Burt, 2004).