Supercritical carbon dioxide (SC-CO2) extraction of Nigella sativa L. oil using full factorial design

In this study, Nigella sativa L. oil was extracted using supercritical carbon dioxide with full factorial design to determine the best extraction condition (pressure, temperature and dynamic extraction time) for obtaining an extract with high yield, antioxidant activity and thymoquinone (TQ) quantity. The maximum thymoquinone content in the highest overall yield was achieved through SC-CO2 extraction condition of 150 bar, 40 °C, 120 min with the value of 4.09 mg/ml. The highest SC-CO2 extraction yield was 23.20% which obtained through extraction condition of 350 bar, 60 °C and 120 min. The extraction conducted at 350 bar, 50 °C, 60 min showed the lowest IC50 value (highest antioxidant activity) of 2.59 mg/ml using DPPH radical scavenging activity method. Fatty acid composition of the extracted oil with highest radical scavenging activity was obtained by gas chromatographic analysis.

► In this study the SC-CO2 extraction of Nigella sativa L. seeds was performed and the effect of extraction parameters such as pressure, temperature and dynamic extraction time was studied on the extract yield, antioxidant activity and thymoquinone content. It was determined that these extraction parameters significantly influenced the extract yield and composition.