Effects of supercritical and liquid carbon dioxide extraction on hemp (Cannabis sativa L.) seed oil

The increase in the popularity of hemp-based products is mainly linked to the presence of non-psychoactive cannabinoids that provide relief from aches, pain and anxiety. In this study, hemp seed oils were produced by two innovative and environmentally friendly extraction techniques: supercritical and liquid carbon dioxide (CO2) extraction. The chemical composition of the two oils was analysed and compared with that of a control oil obtained by solvent (n-hexane) extraction. Both oils obtained by liquid and supercritical CO2 extraction presented interesting compositions: they contained large amounts of cannabinoids, polyphenols and tocopherols and were less oxidised than the control and contained a large amount of hexanal, which provided a pleasant aroma. The maximum cannabinoid content was found in the oil obtained by liquid CO2 extraction (71.51 mg of cannabidiol per kg of oil and 113.92 mg of cannabinol per kg of oil). Carotenoids were prevalent in the oil obtained by supercritical CO2 extraction (61.00 mg kg 1 of oil).