The Antioxidant Potential of Black Cumin (Nigella sativa L.) Extracts Through Different Extraction Methods

Background: Herbal foods possess significant amounts of essential bioactive nutrients and offer clinical and therapeutic benefits. The aim of present research was to compare the antioxidant potential of black cumin extracts obtained using different extraction modes. Materials and Methods: Three solvents (methanol, acetone and hexane) were employed at different time intervals and ratios. However, Supercritical Fluid Extracts (SFE) were obtained at varying pressures (5500, 6500 and 7500 psi). Results: Outcomes revealed that total phenolics were maximum in methanolic extract (790.79±31.67 mg GAE/100 g) at 50 min. Similarly, DPPH and FRAP activity of methanolic extract was also better than other extracts as 80.99±4.02% and 27.44±0.88 mg TE/g, respectively. HPLC quantification exhibited that highest recovery of major bioactive component (thymoquinone) was obtained via supercritical extraction (12.38 mg/g) at 7500 psi. Conclusions: It is concluded that Pakistani variety of black cumin possess appreciable antioxidant activity which directly depends upon the extraction conditions. Among conventional solvents, methanol was evidenced to be more efficient. However, supercritical fluid extracts have proved a reliable mean for the extraction of thymoquinone.