Journal of Food Research; Vol. 2, No. 6; 2013 ISSN 1927-0887 E-ISSN 1927-0895 Published by Canadian Center of Science and Education 1 Phytochemical, Proximate and Nutrient Composition of Vernonia calvaona Hook (Asterecea): A Green-Leafy Vegetable in Nigeria Igile G. O. 1 , Iwara I. A. 1 , Mgbeje B. I. A. 1 , Uboh F. E. 1 & Ebong P. E. 1 1 Department of Biochemistry, College of Medical Sciences, University of Calabar, Calabar, Nigeria Correspondence: Igile G. O., Department of Biochemistry, College of Medical Sciences, University of Calabar, Calabar, Nigeria. Tel: 234-802-279-0020. E-mail: goitech2000@yahoo.com Received: August 2, 2013 Accepted: September 16, 2013 Online Published: September 23, 2013 doi:10.5539/jfr.v2n6p1 URL: http://dx.doi.org/10.5539/jfr.v2n6p1 Abstract The leaf of Vernonia calvaona was analysed for its phytochemical, proximate, anti-nutrient, mineral elements and vitamin compositions using standard analytical procedures. Flavonoids (7.07 ± 0.43%) were the most dominant plant secondary compound, followed by steroidal saponins (4.42 ± 0.23%), phenolic compounds (3.19 ± 0.05%), and carotenoids (1.62 ± 0.11%). Alkaloids (1.26 ± 0.13%), and sesquiterpene lactones (1.64 ± 0.13%) were also present in the plant. The proximate analysis of the fresh leaf gave a carbohydrate content of 20.80± 0.67 mg/100 g, with a corresponding reducing sugar content of 8.56 ± 0.06 mg/100 g. The sample also gave a protein content of 19.80 ± 0.61 mg/100 g and fat content of 4.17 ±0.15 mg/100 g respectively. The total fatty acid content of the plant was 3.57 ± 0.52 mg/100 g. Overall the green-leafy vegetable of Vernonia calvaona which is usually eaten raw and fresh contains a very balanced nutrient composition and provides a total metabolising energy value of 844.49 ± 6.19 KJ/100 g. The plant has a crude fibre content of 7.63 ± 0.22 mg/100 g and an ash content of 10.67 ± 0.33 mg/100 g respectively. The anti-nutrient levels, including oxalates (0.34 ± 0.04 mg/100 g), phytates (0.94 ± 0.04 mg/100 g) and cyanates (0.09 ± 0.01 mg/100 g) were low compared to many known vegetables. The leaf is rich in vitamins (Vit C 11.33 ± 0.88, Vit A 0.61 ± 0.01 and Vit E 0.99 ± 0.13 mg/100 g). The leaf is also rich in vitamins B 1 , B 2 , B 6, niacin and folic acid. The mineral profile of the leaf sample is also impressive, and includes some key elements such as, Fe, Zn, Ca, Na, K, Mg, P and Se. It may be concluded that the leaves of V. calvaona contribute to nutrient intake by the consuming populations in Nigeria and can serve as an antimalarial, antidiabetic, fertility agent, anti-cancer, anti-ulcer and cardioprotective agent. Keywords: Vernonia calvaona, vitamins, mineral elements, secondary compounds 1. Introduction Vernonia calvaona Hook (Astereaceae) is popularly known as “Ekeke leaf” among the indigenous people of the central senatorial district of Cross River State of Nigeria. It is a small shrub of less than 1m tall with petiolate leaves of about 10.0 mm wide which serve as a green-leafy vegetable as well as being used for ethno-medical purposes in Nigeria and Cameroun. It is popularly eaten raw and fresh as a local delicacy with or without palm oil in pepper sauce. It serves as a component of traditional salad among the indigenous consumers. It may also be cooked in native soups and stew, and in the preparation of potatoes, yam and plantain porridge. Its consumption is based on the native belief that the plant as a whole cures heart diseases, blindness, diabetes, malaria, stomach ache and as an anti-helminthic agent. It is eaten to prevent constipation. Most people eat it fresh and raw because the vegetable imparts a sweet taste like sugar in the tongue after its consumption. It is less bitter than the sister plant (Vernonia amygdalina), and yet both plants are used for the same ethno-medicinal purposes. The plant is widely distributed in South Western Cameroun and South-Eastern part of Nigeria, just like its close relatives V. tenoreana, and V. amygdalina. These three species are morphologically similar in many respects, though they can be differentiated using some anatomical features such as the height and broadness of the leaves, as well as the intensity of bitter taste of plant. Of these three species V. calvaona is the shortest in height. On the other hand, V. amygdalina is the most bitter of the three, followed by V. tenoreana and the least bitter is V. calvaona. Nothing has been scientifically reported about V. calvaona, inspite of its rich phytochemical and nutrient composition which contributes significantly to the dietary nutrient intake by the consuming populations of Eastern Nigeria and South Western Cameroun. Its popular sister species (V. amygdalina and V. tenoreana) have been thoroughly investigated with respect to human nutrition, glycaemic effect, lipidemic effect, antimalarial, anthelminthic,