Black Seed Oil: How is it produced?

Nigella is an aromatic plant known since antiquity in North Africa, Egypt, and also the Middle East. Also referred to as black cumin, this plant from the Ranunculaceae family is particularly renowned in traditional medicine for its therapeutic virtues. The oil obtained from its seeds presents itself as an orange liquid, emitting a slightly bitter spicy scent, naturally reminiscent of black cumin seeds.

The biochemical composition of theblack seed oil endows it with several interesting cosmetic properties for the skin and hair. This natural ingredient is particularly recognised for its antioxidant, anti-inflammatory, moisturising and healing virtues.

There are several species of nigella. The most commonly used in cosmetics is the Nigella sativa. Nigella oil can be obtained through various extraction techniques. However, cold pressing remains the gentlest method and is ideal for preserving all the active ingredients contained in nigella seeds. It is carried out without raising the temperature or adding solvent. The following steps are followed to perform a cold press:

1. Following the harvest of the seeds, which typically occurs at the end of July - beginning of August, these are cleaned with a dry clothin order to remove any potential impurities attached to their surface. Similarly, the cold press is cleaned, then sterilised.

2. The seeds are then placed into the oil collector, without overloading it, and are mechanically pressed flat to extract the oil. To carry out the extraction, the temperature must not exceed 25°C, in order not to oxidise and degrade the oil. In the context of cold pressing, a screw press is used to push the kernel into a barrel-shaped cavity. The screw compresses the kernel and the oil comes out through the openings, while the pressing residues (cakes) remain in the barrel. For your information, 1 kg of black cumin seeds can yield approximately 200 to 250 ml of nigella oil.

3. The oil thus collected is filtered to remove impurities and unwanted particles. This results in a purer oil. The black seed oil is then stored in opaque and airtight containers to protect it from light, oxygen, and moisture, factors that can degrade its quality.

• AL-FARGA A. & al. A Narrative Review on Various Oil Extraction Methods, Encapsulation Processes, Fatty Acid Profiles, Oxidative Stability, and Medicinal Properties of Black Seed ( Nigella sativa). Foods (2022).