Comparative Phytochemical Studies and Proximate Analysis of Five Commonly Consumed Vegetables of Southern Nigeria

Background: A comparative qualitative phytochemical screening and proximate analysis were carried out on the leaves of five commonly consumed vegetables of southern Nigeria. These vegetables and families were Telfairia occidentalis (Cucurbitaceae), Gnetum africanum (Gnetaceae), Hagenia abyssinica (Rosaceae), Vernonia amygdalina (Asteraceae) and Piper guineense (Piperaceae).

Methods: Standard methods were used to qualitatively determine phytochemicals (Trease and Evans, Harbone) and proximate composition (AOAC) present in the leaves of G. africanum, T. occidentalis, V. amygdalina, P. guineense and H. abyssinica.

Results: The study revealed the presence of bioactive constituents; tannin, flavonoid, alkaloid, and saponin in the five plant samples except for tannin which was absent in P. guineense. Anthraquinone was absent in all the five samples. Proximate compositions of all the five selected vegetables were not the same. Gnetum africanum had the highest protein, carbohydrate, and ash content (11.16%, 11.46% and 2.35%) respectively when compared with the other plants. H. abyssinica had the highest fibre content at 7.81%, while V. amygdalina had the highest lipid content at 0.50%.

Conclusion: Vegetables should be consumed based on the nutrient requirement of a given person.