Amino Acids and Minerals in a Tropical Nut, Hyphaene coriacea (The Turkana Doum Palm)

Abstract

The Turkana doum palm is an important indigenous plant from an economic standpoint in the Turkana District of Kenya. The various parts of the tree are used for a variety of social, cultural and domestic uses with the nut being an important indigenous wild fruit. However, despite the central place it occupies in the diets of those living along the banks of the major rivers, its nutritional profile is lacking in literature. This study was therefore conducted to document its nutritive composition. In this regard, the protein content of ngapocho and lookot, and the nonessential and essential amino acids in ngapocho were determined. Al so, six minerals were determined in the mesocarp products (apinet and ngapocho) of the nut of the Turkana doum palm, Hyphaene coriacea . The results showed that ngapocho and lookot contained 1.8 and 4.7% protein, respectively. The mesocarp of the nut contains substantial amounts of both the nonessential and essential amino acids and has a chemical score of 66. Threonine is the limiting amino acid. Unlike most plant foods, the nut is an excellent source of the sulphur amino acids methio nine and cystine; it is a good source of isoleucine, leucine, histidine, phenylalanine and tyrosine, and a fair source of tryptophan, lysine, valine and threonine. Ngapocho/lookot contained 17.0/17.4 mg Ca, 4.8/4.2 mg Mg, 0.2/0.2 mg K, 0.5/0.1 mg Na, 13.9/29.8 mg Fe, and 3.4/4.3 mg Zn/100 g. The nut of the Turkana doum palm is quantitatively an excellent dietary source of iron, a good source of zinc, but is a poor source of calcium, magnesium, potassium and sodium. The addition of bovine blood to apinet to make lookot raises the protein, iron and zinc content by more than 160, 100 and 25%, respectively, thus enhancing the nutritional quality of the lookot. Knowledge of the nutrient composition of indigenous food plants such as the Turkana doum palm is important for the purpose of educating the public on the nutritional value of indigenous food plants available in their immediate environments and for conservation efforts.