Ultrasonic-assisted supercritical fluid separation removing plasticizers from ganoderma lucidum spores’ oil

Ultrasonic-assisted supercritical fluid separation (USFS) was firstly applied to regulate solubility and remove plasticizers from ganoderma lucidum spores' oil to improve product safety. Separation efficiency was related with four variables, including temperature, pressure and ultrasonic power. The QD-T6A ultrasonic generator probe, which provided for the study with adjustable ultrasonic power 0 W to 800 W and the ultrasonic frequency was 40 kHz, was fixed at the entrance of the primary separation kettle. The optimal separation conditions were determined to be temperature as 15.0 °C, pressure as 18.0 MPa, and ultrasonic power as 360 W of ultrasonic power on the basis of response surface methodology (RSM). Experimental Di-n-butylphthalate (DBP) and Diethyl phthalate (DEP) content were 0.09 mg and 0.04 mg, respectively, which were below the limits for plasticizers. Meanwhile, the total triterpene and ganoderic acid A contents were 6.89 g and 1.10 g, respectively, comparable to conventional supercritical fluid extraction. The experiments with USFS at different power intensities revealed that ultrasonic at a power intensity of 36 W/L and the power density of 0.20 W/cm2 could resolve the separation contradiction between ganoderma lucidum spores' oil and plasticizers. This study revealed that USFS could be an innovation in the field of ultrasonic separation, with numerous potentials uses in pharmaceutical manufacturing.