Nigella sativa Seed Cake: Nutraceutical Significance and Applications in the Food and Cosmetic Industry

Abstract

Nigella sativa is an annual flowering plant and one of the most significant seeds in the history of medicinal importance. It is popularly used in the bakery industry and medicinal products. It is an annual spicy herb indigenously belonging to Mediterranean regions. The seeds are extracted using a screw press machine to yield oil (32–40%) leaving behind residue meal which is an abundant source of macro as well as micro-nutrients. Macronutrients include protein and fibres, whereas micronutrients include vitamins and minerals. Even after extraction of the oil from the seed, the defatted black cumin seed cake still contains some residual oil rich in bioactive components apart from the main constituents of the meal. The defatted cake is utilized as an animal feed owing to ample protein content and can also act as a high source of phenolic compounds and carbohydrates that could aid in strengthening the immune system. The meal contains most essential amino acids along with crude protein. The production of black cumin defatted seeds is expected to increase shortly due to its extended use as a medical seed. It has been also reported to replace protein in the diets of growing Japanese quail. Despite nutritional as well as economic importance, there is a dearth of literature about the black cumin seed cake. Some of the pivotal works have reported about the rich amino acid profile of the seeds. The meal obtained could be a good alternative for feed for animals. Apart from high crude protein, the defatted cake has been also reported to contain high crude fibres. It has been also reported to be a good replacement for soybean meal. Studies have reported also the utilization of seed cake as a rabbit feed without hampering liver or kidney function. The application of black cumin seeds also finds its prevalence in protective cosmetics owing to its high antioxidative properties.