Assessment of Nutritional Value of Selected Underutilized Green Leafy Vegetables in Southwestern Nigeria

Abstract

The need for underutilized leafy vegetables as food has been greatly emphasized owing to the increase in knowledge of the value of the essential nutrients they can provide. In this study, an assessment of the nutritional value of underutilized leafy vegetables collected in Southwestern Nigeria, and their content for mineral nutrients (K, Na, P, Ca, and Mg), essential vitamins (A, C, and E), and proximate composition was carried out on ten vegetables: Jatropha tanjorensis, Solanum nigrum, Talinum triangulare, Solanecio biafrae, Vernonia amygdalina, Crassocephalum crepidoides, Telfairea occidentalis, Amaranthus hydridus, Launaea taraxacifolia and Solanum macrocarpon. From this study, it was observed that the ten vegetables provide mineral concentrations exceeding 0.01%, essential vitamins exceeding 0.5%, ash exceeding 5%, moisture exceeding 5% of plant dry matter, crude fiber exceeding 10%, protein, crude fat exceeding 5%, and carbohydrate exceeding 30%. High levels of potassium, vitamin A, vitamin C, crude fat, and carbohydrates were noticed in Jatropha tanjorensis. High levels of both sodium and calcium were noticed in Solanecio biafrae. Amaranthus hydridus, Vernonia amygdalina, and Solanum nigrum were noted to be good sources of protein. The range of values of mineral nutrients, essential vitamins, proximate composition, and recommended dietary allowances of the studied leafy vegetables are very similar to those obtained in typical conventional edible leafy vegetables. The results therefore provide evidence that these underutilized leafy vegetables are well endowed with essential nutrients and could be important contributors to improving the nutritional content of humans.