Nutritional and Preservative Potential of Tunisian Nigella sativa L. Seeds: Insights into Lipid Composition, Antioxidant Activity, and Antimicrobial Effects

Research on new natural resources with nutritional and preservative properties has gained increasing interest among modern consumers and the contemporary food industry.In this context, this study aimed to explore the bioactive potential of Nigella sativa L. seeds collected from various locations in Tunisia.The results highlight the considerable potential of N. sativa seeds for oil production, due to high oil yield (23-28%).These findings also reveal the abundance of bioactive lipids, including linoleic acid (C18:2, 49.66 to 58.47% of total fatty acids), β-sitosterol (88.19 to 100.46 mg/100 g oil), triacontanol (24.13 to 30.48 mg/kg oil), and α-tocopherol (10.38 to 11.51 mg/100 g oil).The hydroethanolic seed extracts exhibited the highest antioxidant activity compared to the ethanol and aqueous extracts, due to their higher contents of phenolic compounds, with total phenolic content ranging from 72.50 to 74.35 mg GAE/g, total flavonoid content from 23.48 to 29.47 mg QE/100 g, and total tannin content from 7.18 to 8.07 mg CE/g.Furthermore, ethanolic extracts showed antibacterial activity against bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, and Staphylococcus aureus frequently found in rotten food products.These findings underscore the value of N. sativa seeds as a rich source of natural compounds with good potential for use in food preservation and nutritional enhancement.