ASSESSMENT OF MINERAL OLIGO-ELEMENTS IN THE LEAVES
OF GNETUM AFRICANUM AND GNETUM BUCHHOLZIANUM HARVESTED IN THE FORESTS OF SOUTH CAMEROON
J. F. Sabouang1,2, R. M. Nemba1,2*
1National Radiation Protection Agency, Ministry of Scientific Research and Innovation, PO BOX 33732 Yaounde – Cameroon.
2Department of Inorganic Chemistry, Faculty of Sciences, University of Yaounde I, PO. Box 812, Yaounde, Cameroon.
* Corresponding author. E-mail: firstname.lastname@example.org
Received: 18 February 2009; revised version accepted: 12 March 2009
Gnetum africanum and Gnetum buchholzianum are two gnetaceae species encountered in the forests of Africa. Both species exist in Cameroon. They are part of the main non woody forest products exploited by the local populations for food and medical issues. The present survey, conducted in one main zone of production called Plateau Sud Camerounais, consists in valuing the oligo elements content of the leaves of these plants and discussing the differences of concentrations within two species. The results obtained for Gnetum africanum are compared to those reported in the literature for samples of the same species collected in the South-East of Nigeria. The analyses performed by EDXRF reveal in the two species collected in Cameroon the presence of the following mineral elements: K, Ca, Mn, Fe, Ni, Cu, Zn, Rb and Sr. The global concentration of the first four elements represent more than 99% of the total concentration of the elements previously enumerated. Calcium is about three times more concentrated in the leaves of Gnetum buchholzianum than in those of Gnetum africanum. For sake of comparison the results of the previous analyses of the leaves of Gnetum africanum collected in Nigéria show that K, Ca, Fe and Zn are at least four times more concentrated in the samples collected in Cameroon. It is to be noticed that in both regions major elements encountered in Gnetum africanum are potassium, calcium and iron.
Keywords: Gnetum africanum; Gnetum buchholzianum; oligo-elements; bio-availability.