Supercritical CO2 extraction of lavender flower with antioxidant activity: Laboratory to a large scale optimization process
Encarnación Cruz Sánchez, Jesús Manuel García-Vargas, Ignacio Gracia, Juan F. Rodrı́guez, María Teresa García
Abstract
The volatile compounds that comprise lavender essential oils, including linalool and linalyl acetate, have demonstrative therapeutic properties. The supercritical CO2 extraction (scCO2) has demonstrated efficiency and selectivity for the extraction of essential oils from vegetable matrices. The solubility of lavender essential oil in scCO2 was determined using a high-pressure variable-volume and modeled by semiempirical models. Supercritical extraction was carried out at a pressure of 180, 250 and 300 bar and a temperature of 40–60 °C, with and without cosolvents. kinetic curve has been modeled by broken and intact cells model developed by Sovová. The composition of the extracts was evaluated through GC–MS and their antioxidant activity by the DPPH method. The highest values of oil solubility and extraction yield were obtained at 250 bar and 60 °C. Furthermore, the extraction yield increases significantly with the addition of ethanol as a co-solvent (0.2 % v/v). A complete set of equilibrium data and kinetic parameters has been reported on a large scale for the first time. The dominant components identified in the extract were linalool and linalyl acetate, and the extracts showed very satisfactory results for antioxidant capacity. Compared with traditional methods like Soxhlet extraction, the supercritical extracts were determined to be more interesting for the formulation of nutraceutical products or biomedical applications.