Chemical composition of bitter cola (Garcinia kola) seed and hulls

The chemical composition of Garcinia kola seed and hull was determined using standard methods. Results show that crude protein, lipid extract, ash, and crude fibre ratios are: 39.52 and 99.92 g/kg, 43.25 and 42.91 g/kg, 11.42 and 18.62 g/kg, 114.02 and 153.44 g/kg respectively. Carbon : nitrogen ratios for the seed and hull are 57.88 and 29.01, respectively. Garcinia kola hull had significantly higher (p<0.05) protein and fibre but has comparable values for lipid and ash. Potassium and phosphorus were the most abundant mineral elements in Garcinia kola seed (334.82 and 242.61 mg/kg, respectively) while phosphorus predominates in the hull (288.61 mg/kg). The seed had significantly higher values for sodium, potassium, copper and cobalt while chromium, molybdenum, manganese, nickel, selenium, lead and mercury were not detected. The dominant saturated, monosaturated, and polyunsaturated fatty acid, in the seed and hull are palmitic (31.55 and 276.01 mg/kg), oleic (38.36 and 52.77 mg/kg) and linoleic acids (36.16 and 235.83 mg/kg) respectively. The hull has significantly higher (p<0.05) a-linolenic acid content. Glutamic acid is the dominant non-essential amino acid in seed and hull (6.80 and 8.10 g/kg, respectively) while lysine and valine (2.40 and 7.10 g/kg, respectively) are the dominant essential amino acids. The proportion of essential amino acid in the total amino acid is 44.52% in the hull and 35.81% in the seed. Garcinia kola seeds and hulls may find use in food and feed formulations by virtue of their chemical composition.