Assessment of Nutritional and Bioactive Components of Garcinia kola Chips

Abstract

Garcinia kola otherwise known as bitter kola has been used in traditional African medicine for centuries, and is considered to have many beneficial properties. The study was aimed at assessing the nutritional and bioactive components of bitter kola chips. Freshly harvested seeds of Garcinia kola were purchased from local markets in Ado Ekiti, Nigeria. The seeds were thoroughly washed with clean water, de-husked, sliced and fast-dried at room temperature under high air current, to obtain bitter kola chips. The dried bitter kola chips were ground into fine powder using an electric blender. The fine powder was then analysed for its proximate, minerals, vitamins, phytochemicals and essential oil content. The results showed low moisture content (8.47 %), moderate levels of protein (12.7 %), fat (6.27 %), ash (7.47 %) and crude fibre (6.27 %), as well as very high levels of carbohydrate (58.77 %) and metabolizable energy (3000 Kcal/Kg). The micronutrients present in bitter kola consists of Fe2+, Zn2+, Mg2+, Ca2+, K+, PO3-, ascorbic acid, thiamine, niacin, and riboflavin at concentrations of 9.37, 0.23, 23.33, 238.33, 26.67, 323.33, 18.23, 0.27, 0.13 and 0.60 mg/100g respectively. The bitter kola chips contained high levels of alkaloids (628.33±10.41 mg/100g), saponins (161.67±7.64 mg/100g), and tannins (233.33±7.64 mg/100g); moderate levels of flavonoids (58.33±5.41 mg/100g), phytates (63.33±2.89), oxalates (90.00±5.00) and oxygen radical absorption capacity (13.23±0.25); while the anti-protease activity and cyanogenic glycosides levels were very low. GCMS analysis of the oil components of G. kola chips showed the presence of molecules such as Trichloroacetic acid, Ar-tumerone, Tumerone, which are of significant importance to human health. Sensory evaluation showed high preference for the bitter kola chips than the fresh seeds.