Supercritical CO2 Extraction of Volatile Oil from Rose Concrete

Rose concrete obtained from Rosa damascena Mill. was fractionated by supercritical CO2 extraction at 80 bar pressure and 40°C temperature by using a two-stage separation procedure. Two products, containing mainly paraffins and volatile oil, were recovered in the first and in the second separator, respectively. The volatile oil was analysed by GC–MS and compared with the products obtained from rose concrete by steam distillation and ethyl alcohol solubilization. The supercritical rose oil and the steam distilled product had very different compositions. The major difference was in the 2-phenylethanol content which was 50.0% in the SFE product and 10.4% in the steam-distilled rose oil. The liquid product obtained by ethyl alcohol solubilization contained 28.3% of 2-phenylethanol but more than 46% of paraffins, whereas the supercritical volatile oil contained only 15.1% of these compounds.