Extraction of squalene from aquilaria malaccensis leaves using supercritical carbon dioxide

Abstract

Supercritical carbon dioxide (SC-CO2) and Soxhlet extraction were performed on Aquilaria malaccensis leaves. The focus of this research is to investigate the effect of temperature and pressure of SC-CO2 conditions on extract yield, squalene composition and solubility of extract. In addition, the comparison in terms of extract yield and squalene composition was also done with Soxhlet extraction. The final objective is to optimize the SC-CO2 extraction of Aquilaria malaccensis leaves assisted by a co-solvent using the response surface methodology (RSM). The effects of SC-CO2 at various pressures and temperatures were investigated on extraction yield and squalene concentration in Aquilaria malaccensis leaves extracts. This research was conducted at temperature and pressure of 45 °C to 75 °C and 10 MPa to 30 MPa, respectively, and assisted by 2% ethanol as a co-solvent. The effect of variables and the optimum conditions of extraction yield, squalene concentration, and solubility of extract were examined in the RSM. In comparison, the Soxhlet extraction produced the highest extraction yield (45.66%), whereas SC-CO2 gave the highest squalene concentration (14.83 wt%). The optimization of SC-CO2 extraction adequately fits the second-order polynomial model with the coefficient of determination, R2 of 0.9452 (extraction yield), 0.8685 (squalene concentration) and 0.7770 (solubility of extract) at 95% confidence level. The predicted values of optimum yield of extract (12.2655%), squalene concentration (12.0295%) and solubility of extract (0.0138611) were obtained at 63.66 °C and 30 MPa during 1 hour of extraction. Thus, the extraction of squalene from Aquilaria malaccensis leaves using SC-CO2 was improved in terms of quality and purity of extract compared to the Soxhlet extraction.