NUTRITIONAL POTENTIALS AND CHEMICAL VALUE OF SOME TROPICAL LEAFY VEGETABLES CONSUMED IN SOUTH WEST NIGERIA
Sobowale, S.S1*; Olatidoye, O.P2; Olorode, O.O1, and Akinlotan, J.V1
1Department of Food Science and Technology, Moshood Abiola polytechnic, Nigeria
2Department of Food Science and Technology, Igbinedion University Okada, Nigeria
Email: sunsam_2003@yahoo.co.uk
ABSTRACT
The human population in tropical African depends largely on a number of edible leafy vegetables to meet up with shortages in minerals and vitamins. Data base on the nutritional value of these leafy vegetables is scanty. Therefore, we report the nutritional components in three species of leafy vegetables using standard analytical methods. All the vegetables contained moisture (79.92 to 84.0%), crude protein (20.61 to 22.7%), crude fibre (10.7 to 22.44%), ash (6.8 to 10.44%), carbohydrate (55.86 to 68.22%) crude lipid (4.24 to 5.6%) and food energy (1507.19 to 1673.96 kJ/100g). The mineral element content were high with remarkable concentration of K(35.2 to 48.8mg/100g),Na(11.4 to 14.4 mg/100g),Ca(15.4 to 18.7mg/100g), Mg(12.2 to 18.7mg/100g), P(13.8 to 15.08mg/100g). The relationship between Na and K as well as between Ca and P; are desirable with the respective ratios of Na/K (0.6) and Ca/P (1.2). They also contain high levels of carotenoids (30 to 41.5 mg/100g DW), vitamin C (137.5 to 197.5 mg/100g DW). Seventeen amino acids (isoleucine, leucine, lysine, methionine, cysteine, phenylalmine, tyrosine, threonine, valine, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, proline and serine) were detected. Their amino acid composition compare favourably with that of WHO/FAO protein standard indicating favourable nutritional balance except for lysine and methionine which appear marginal. The nutritional values of the phytochemicals were also assessed with a view of establishing and understanding their nutritional uses. The functional properties for the three vegetables were similar. Comparing the nutrient and chemical constituents with recommended dietary allowance (RDA) values, the results reveal that the leaves contain an appreciable amount of nutrients, minerals, vitamins, amino acids and phytochemicals and low levels of toxicants.
Keywords: vegetables, nutrients, amino-acids, phytochemicals, functional properties