Comprehensive analysis of amino acid and fatty acid profiles in black cumin (Nigella sativa) oil cake as a potential feed component

Oil cakes obtained after mechanical oil extraction from oilseeds are increasingly recognized as valuable feed ingredients due to their residual protein and lipid fractions. We evaluated the nutritional potential of black cumin ( Nigella sativa) seed oil cake produced by hydraulic pressing, focusing on its amino acid and fatty acid profiles. Samples were analyzed using high performance liquid chromatography for amino acids and gas chromatography for fatty acid methyl esters. The results were compared with those of rapeseed, amaranth, and hemp oil cakes. Black cumin oil cake contained a wide spectrum of amino acids. Total essential amino acids reached 112.14 g/kg, while non essential amino acids summed to 167.94 g/kg. Among fatty acids, linoleic acid (C18:2 n-6) dominated the lipid fraction at 51.96% of total fatty acids. Notably, caproic acid (C6:0) was detected only in black cumin samples at 0.142%, and eicosadienoic acid (C20:2) was present at 2.27%, a concentration markedly higher than in the other crops examined. These compositional features suggest that black cumin oil cake may serve as a distinctive feed ingredient with potential functional properties.