Proximate and Mineral Composition of Some Leafy Vegetables Sold in Farin Gadan Market in Jos, Plateau State, Nigeria

Abstract

This study was carried out to determine the mineral concentration and proximate composition of four different leafy vegetable collected in from Farin Gadan Market Jos Plateau State Nigeria and extracted using double acid extraction method. Heavy metals concentration was performed using atomic absorption spectrophotometer and proximate composition was determined by Association of, Official Analytical chemistry (AOAC,1999) method. Results showed that the highest level of lead was found in Jute (0.045 ±0.004) while Lettuce (0.001 ±0.007) had the lowest level of lead. The leafy vegetables in this study may have been polluted with lead through pollutants in irrigation water, farm soil or due to pollution from the highway traffic. Chromium and cadmium were observed to be low in all the leafy vegetables analyzed, which is still within the safe limit set by FAO/WHO. Zinc had the highest concentration (2.802± 0.012) in bitter leaf, proximate analysis indicated significant variability in the constituents contained in the leafy vegetables studied (Carbohydrate, Ash content, crude protein, crude fats, crude fibre and moisture content in descending order). The highest moisture content was found in Lettuce (7.791%) and the highest crude protein in Bitter leaf (12.88%). The concentrations of the toxic heavy metals are within the tolerable limits of some regulatory authorities. However, there is need for continuous monitoring of heavy metal and proximate analysis in leafy vegetables because, leafy vegetables are the main sources of food supplements for humans in many parts of the world and are considered as bio-indicators of environmental pollution.