Green and selective supercritical fluid extraction of essential oil and cannabidiol from Cannabis sativa L.

Abstract

In this study, supercritical fluid extraction (SFE) was used to extract cannabis essential oil and cannabinoids from the same matrix by changing decarboxylation conditions and CO2 density. Cannabis essential oil was extracted at 90 bar and 50°C (0.288 g/cm3 CO2 density), and it was mainly composed of α-pinene, eucalyptol, β-caryophyllene, and selinene. Subsequently, decarboxylation was carried out on the vegetable matter operating at 105°C for 15 min and, then, at 120°C for 1 h. The largest cannabidiol (2.96% w/w) yield was obtained when SFE was performed at 100 bar and 40°C (0.623 g/cm3 CO2 density). An effective online fractional separation of the extracted compounds was also obtained by SFE, since no cuticular waxes were detected in GC–MS traces of the products of interest. Operating in this way, expensive, time-consuming, and polluting post-processing steps of separation were not required, producing a ready-to-use extract for the market.