Abstract
Nigella sativa L. is a fragrant plant that belongs to the Ranunculaceae family. It is commonly used as a form of traditional medicine in Middle-Eastern countries. In this study, Nigella seed oil from Saudi Arabia was extracted using the cold press and Soxhlet methods to investigate the effects of solvents polarities on yield and antioxidant properties. The analysis revealed that the highest yield (40%) of oil was obtained with ethanol solvent. The aqueous methanol extract the highest level of total phenolic compounds (239 mg GAE/g). Moreover, the methanol extract showed the most elevated 2,2-Diphenyl-1-picrylhydrazyl radical rummaging assay, at 59%. The ferric reducing and antioxidant power activities of the oils extracted with ethanol and tetrahydrofuran were 13,199 and 13,326 mmol Fe2+/100 g dry weight, respectively. Thus, the findings show that a high level of natural antioxidants can be derived from Nigella sativa oil extracted by ethanol solvent.