Characterization of essential oils from Helichrysum odoratissimum using different drying methods

Helichrysum odoratissimum is one of the most commonly used medicinal plants in South Africa. The essential oil from the herb was extracted and characterized for the first time using different drying methods. The oils isolated from fresh, air-dried, sun-dried and oven-dried aerial parts of the plant yielded 0.28, 0.46, 0.33 and 0.36%, respectively. The fresh leaf oil was characterized by a high content of oxygenated monoterpenes with the main constituents as p-menthone (35.4%), pulegone (34.2%) and 1,8-cineole (13.0%). The dried plant oils had limonene (31.6-22.6%), β-caryophyllene (13.0-12.0%) and α-pinene (10.0-7.7%) as their major constituents. Generally, the yield and chemical profile of H. odoratissimum were affected by the drying methods utilized. There were noteworthy chemical alterations in the major components of the essential oils using different methods of drying. The compounds pulegone and menthone were reported as potentially harmful compounds, hence their substantial reduction in the dried oils as compared to the fresh leaf oil is noteworthy as it aids reduction of toxicity in the oils. © 2007 Asian Network for Scientific Information.