The olive (Olea europaea) is a species of small tree in the family Oleaceae, native to the coastal areas of the eastern Mediterranean Basin (the adjoining coastal areas of southeastern Europe, western Asia and northern Africa) as well as northern Iraq, and northern Iran at the south end of the Caspian Sea.
Its fruit, also called the olive, is of major agricultural importance in the Mediterranean region as the source of olive oil. The tree and its fruit give its name to the plant family, which also includes species such as lilacs, jasmine, Forsythia and the true ash trees (Fraxinus).  The olive tree, Olea europaea, has been cultivated for olive oil, fine wood, olive leaf, and the olive fruit. A very simple method is proposed to produce, using non-homogeneous hyperthermophilic β-glycosidase immobilised on chitosan, 3,4-dihydroxy-phenylethanol (hydroxytyrosol), a commercially unavailable compound with well known biological properties which justify a potential commercial application.