Improving the Efficiency of Extracting Nigella sativa Oil through Pretreatment: Effects on Yield and Active Constituents

The plant known as black seed, or Nigella sativa, is well-known for its small, jet-black seeds, which are bursting with health benefits. Because of the oil’s potent therapeutic properties, there has been a lot of interest in its extraction from these seeds. The effectiveness of steam and microwave pretreatments on Nigella sativa seed oil extraction is examined in this study, along with their impact on oil yield and active ingredients. Two extraction techniques, hydrodistillation and supercritical fluid extraction, are used to investigate the effects of different pretreatment times on seed samples. The results show that utilizing hydrodistillation, microwave pretreatment for three minutes (HM3) produces the maximum oil extraction (0.892%), outperforming untreated samples (H0) at 0.436%. In the same direction, samples that have been microwave-pretreated for three minutes (HS3) in supercritical fluid extraction show the highest yield (9.44%) when compared to their untreated counterpart (SO), which shows a yield of 4.10%. Microwavetreated samples exhibit a more noticeable increase in oil yield, even if steam pretreatment also improves it. Furthermore, H0 has a 19.40% Thymoquinone level, which is crucial for the active ingredients in the oil, but pretreatment HM3 samples have an increased 26.73% Thymoquinone content. On the other hand, the Thymoquinone content in supercritical fluid-extracted S0 is 8.35%, while pretreatment SM3 samples show 11.53%. Thymoquinone content lags despite supercritical fluid extraction’s greater yield; this could be because the technique has a lower operating pressure (70 atm). The results of this study highlight how pretreatment techniques can increase oil yield without lowering oil quality or antioxidant activity. Prospective enhancements in process parameters, namely in the operating pressure of supercritical fluid extraction, could potentially augment Thymoquinone content and augment oil yield. The results validate the feasibility of pretreatments in maximizing the extraction efficiency of Nigella sativa oil while preserving its antioxidant qualities and oil quality.

• Balancing oil yield and quality through pretreatment techniques.

• Effect of microwave pretreatment on Nigella sativa oil extraction efficiency.