Effect of Drying on the Composition of Essential Oil from Lavandula angustifolia

Qualitative and quantitative differences in essential oil hydrodistilled from fresh and dried flowers of lavender (Lavandula angustifolia) harvested in Poland were investigated by gas chromatography-mass spectroscopy (GC-MS) and near infrared spectroscopy (NIRS). Drying prior to hydrodistillation resulted in large losses of essential oil (over 40 %). Sixty-five compounds were identified in the essential oil isolated from fresh material and 73 in that from dried material. The main ingredients of the essential oil were oxygenated monoterpenes (over 70 %). Essential oil from dried lavender was shown to have smaller quantities of monoterpene esters (12.9 %) with an increased amount of alcohol (4.3 %).The possibility of using NIRS for rapid and precise identification of essential oils as well as for determination of the origin of plant material was successfully demonstrated.