The present work investigates the chemical composition of black cumin (Nigella sativa L.) cake obtained as a by-product of cold-pressed oil extraction. The aim of the study is to assess its potential for further utilization and secondary applications. By applying a combination of analytical techniques, including chemical analysis, Soxhlet extraction, ICP-OES, ICP-MS, FTIR, and SEM-EDS, the material was characterized as a rich organic matrix with a significant residual fat content (approximately 20%), proteins, and essential mineral elements such as K, Ca, Fe, Cu, Zn, and P, while containing low levels of toxic elements. Since cold pressing preserves residual bioactive compounds, and considering the high content of essential elements, black cumin cake represents a promising ingredient for food supplements. In addition, its porous surface structure observed by SEM-EDS, together with the functional groups identified by FTIR analysis, suggests potential sorption properties. These findings position black cumin cake as a promising resource within the framework of sustainable agro-industrial waste valorization strategies.
Младенов et al. (Sat,) studied this question.