An original solvent free microwave extraction of essential oils from spices

Attention is drawn to the development of a new and green alternative technique for the extraction of essential oils from spices. Solvent-free microwave extraction (SFME) is a combination of dry distillation and microwave heating without added any solvent or water. SFME and hydrodistillation (HD) were compared for the extraction of essential oil from three spices: ajowan (Carum ajowan, Apiaceae), cumin (Cuminum cyminum, Umbelliferae), star anise (Illicium anisatum, Illiciaceae). Better results have been obtained with the proposed method in terms of rapidity (1 h vs. 8 h), efficiency and no solvent used. Furthermore, the SFME procedure yielded essential oils that could be analysed directly without any preliminary clean-tip or solvent exchange steps. Copyright (C) 2004 John Wiley Sons, Ltd.