Physico-chemical evaluation of Rosmarinus officinalis L. essential oils

nineteen samples of rosmarinus officinalis were extracted by steam distillation in a pilot plant and evaluated in terms of chemical compositions and physico-chemical characteristics. the volatile oil yields ranged from 0.37% (1999 harvest) to 0.49% (1998 harvest). twenty components were identified in the oils. the major components were alpha-pinene (40.55 to 45.10%), 1,8-cineole (17.40 to 19.35%), camphene (4.73 to 6.06%) and verbenone (2.32 to 3.86%). the physico-chemical parameters averaged 0.8887 g/cm3 for specific gravity, 1.4689 for refractive index, and +11.82° for optical rotation, and there were no significant variations in either the chemical or physico-chemical data in the different years.