Evaluation of the proximate composition and metal content of spinach (Spinacia oleracea) from selected towns in Nasarawa State, Nigeria

Abstract

A study was carried out to evaluate the metal and proximate content of spinach (Spinacia oleracea) commonly consumed in Nasarawa State, Nigeria in order to ascertain its suitability for consumption. The metal concentration was determined using Atomic Absorption Spectrophotometer (AAS) and the proximate content was determined according to the method described by Association of Analytical Chemist (AOAC). The results obtained varied with the sampling locations. The mean concentration of the metals ranged from: Zn (2.09-2.48 mg/kg), Pb (0.24-0.73 mg/kg), Mn (3.20-8.52 mg/kg), Cu (0.21-0.31 mg/kg) and Ni (0.01-0.23 mg/kg). The values for proximate content showed that moisture content ranged from (1.00-1.45 %), ash content (8.63-8.74 %), crude protein (14.13-14.44%), crude fibre (2.52-2.63%), crude fat (23.02-23.11%) and carbohydrate (50.10-50.59%). The result obtained does not reveal any significant level of contamination by heavy metals as most of the values were within the permissible limits of consumption of vegetables. However, the growing of the plant in locations near pollution sites should be discouraged. As for the proximate content the values obtained are indication that all the samples are rich sources of protein, fibre, and carbohydrates with a high probability of storage due to their significant moisture content. This underscores their nutritive value as a viable option for plant base nutrients for consumption.