Nutritional, Phytochemical, and Toxicological Evaluation of Black Olives (Canarium schweinfurthii) Seed Kernel: A Potential Resource from Environmental Waste
Canarium schweinfurthii (black olive) seed is an underutilized tropical seed often discarded as waste despite its nutritional and medicinal potential. This study evaluated the nutritional, phytochemical, mineral, amino acid, and toxicological properties of C. schweinfurthii seed kernel using standard methods. Proximate analysis showed moisture (7.12%), ash (3.10%), crude fibre (12.14%), crude fat (38.23%), protein (22.10%), carbohydrate (10.11%), dry matter (92.88%), and energy value (472.91 kcal/100g), indicating a nutrient-dense profile. Phytochemical screening revealed the presence of saponins, tannins, flavonoids, alkaloids, cardiac glycosides, phenolics, and steroids. Quantitative values were tannins (355.27 ± 0.24 mg/100g), flavonoids (351.00 ± 0.67), alkaloids (321.10 ± 0.01), cardiac glycosides (321.00 ± 0.11), resins (248.00 ± 0.21), and saponins (29.50 ± 0.05). Mineral analysis indicated calcium (36.1 ± 0.03), potassium (24.2 ± 0.02), phosphorus (18.0 ± 0.04), magnesium (16.0 ± 0.01), sodium (10.2 ± 0.01), zinc (8.0 ± 0.01), iron (7.4 ± 0.01), copper (4.3 ± 0.00), manganese (0.2 ± 0.00 mg/100g), with undetectable lead and cadmium, affirming its safety. Amino acid profiling revealed total amino acids (97.63 ± 0.18 g/100g protein), including phenylalanine (9.10), isoleucine (8.10), arginine (7.01), leucine (6.10), histidine (5.81), aspartic acid (13.25), and glutamic acid (12.12). Acute toxicity studies showed no adverse effects at 5000 mg/kg, indicating non-toxicity. These results support the valorization of C. schweinfurthii seed kernel as a safe, nutrient-rich resource for functional food applications.
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