Abstract
This study focused on the recovered essential oil of Yulania denudata fresh flowers obtained from hydrosol, the main by-product of Y. denudata essential oil production. The yield percentage and chemical profile of the recovered oil (extracted from the hydrosol by adsorption and solvent extraction, respectively) were investigated and compared with those of the decanted oil (obtained directly by field distillation of fresh flowers). Decanted oil accounted for 91.3–92.1% and recovered oil 7.9–8.7% of the total oil yield. The decanted oil was rich in hydrocarbons (78.2%), whereas the recovered oil was rich in organoleptically important oxygenated compounds (99.1–99.5%). For the recovery of dissolved essential oil from Y. denudata hydrosol, adsorption using activated carbon was preferred over diethyl ether extraction due to higher efficiency and lower solvent consumption. The recovered oil is a rich source of eucalyptol, which finds uses in the fragrance and pharmaceutical industries.
Acknowledgements
The authors acknowledge Zhejiang University for supply of plant materials. The authors thank Dr. Yongjiang Wu for his guidance in gas chromatographic analysis.