Nutritive Value and Heavy Metal Concentrations of Selected Wild and Domesticated Vegetables Consumed in South East, Nigeria

Abstract

The vitamin composition, amino acid profile and heavy metal levels of Lasianthoreafricana (LA), Heinsia crinata (HC), Vernonia amygdalina (VA) and Telfairiaoccidentalis (TO) were investigated using standard methods. Niacin was highest in Lasianthore Africana (3.61 mg/100 g) followed by Heinsia crinata (3.30 mg/100 g) and lowest in Vernonia amygdalina (1.24 mg/100 g) and Telfairiaoccidentalis (1.04 mg/100 g). Vitamin C content was highest (208 mg/100 g) in Telfairiaoccidentalis (TO) and lowest (29.3 mg/100 g) in Heinsia crinata (HC). There was no significant difference (p>0.05) in vitamin A content of all vegetables. Vernonia amygdalina had the highest (2.99 mg/100 g) vitamin B₂ level while Telfairiaoccidentalis (TO) had the lowest value of 1.73 mg/100 g. Telfairiaoccidentalis had the highest value of vitamin E (42.3 mg/100 g) followed by Vernoniaamygdalina (32.6 mg/100 g) and lowest in Heinsia crinata (HC) (1.45 mg/100 g) while vitamin K was highest (2.26 mg/100 g) in Telfairiaoccidentalis (TO) and lowest (1.23 mg/100 g) in Lasianthore Africana (LA). Analysis conducted showed that the vegetables were comparatively rich in total essential amino acids. Telfairiaoccidentalis (TO) had the highest total amino acids (905 mg/100 g protein); Vernoniaamygdalina (VA) had the highest total essential amino acids (52.2 %), Lasianthore Africana (LA) followed with 51.4 %. Lasianthore africana had the highest total sulphur containing amino acids (6.3 %) while Vernoniaamygdalina (VA) had the highest amount of total aromatic amino acids (15.3 %). Zn, Fe and Cu were moderately in low concentrations but Cd and Pb were absent.

Keywords: Nutritive value, Heavy metal concentrations, wild and domesticated, vegetables.