Superheated water extraction of essential oils from Cinnamomum zeylanicum (L.)

Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored.

To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.) bark and leaves as typical plant materials to determine if this extraction method can yield a higher quality oil.

Samples of cinnamon bark or leaves were extracted at 200°C with water under pressure. The essential oils were obtained from the aqueous solution using a solid phase extraction cartridge and were then examined by GC-MS.

Using superheated water extraction, cinnamon bark oil with over 80% cinnamaldehyde and cinnamon leaf oil containing up to 98% eugenol were obtained. Alternative solvent extraction methods were also studied but led to emulsion formation apparently because of the presence of cellulose breakdown products.

Superheated water extraction offers a cheap, environmentally friendly technique with a shorter extraction time than hydrodistillation and yielded a higher quality oil with a higher proportion of eugenol than hydrodistillation.