Analytical Indices and Comparative Evaluation of Some Metalsin Palm Oil, Groundnut Oil and Soybean Oil from Nigeria

Samples of palm oil, groundnut oil and soybean oil were collected from Ose and Ochanja markets of Onitsha town of Anambra State, Nigeria. They were analyzed for copper, iron, chromium, aluminium, lead and cadmium. The concentrations (mgkg-1) of each of these elements were determined. Palm oil gave 11.371, 0.079, 2.3319, 0.1780, 1.9358 and 0.0220 for iron, copper, chromium, lead, aluminium and cadmium respectively. Groundnut oil gave 8.5109,0.0633,2.7067, 0.1631, 1.7742 and 0.0207 for iron, copper, chromium, lead, aluminium and cadmium respectively. For soybean oil sample, the levels (mgkg^-1) were 8.7519,0.0475,1.7559,0.1631,0.3837 and 0.0200 for iron, copper, chromium, lead, aluminium and cadmium respectively. Values of the physical properties showed that the saponification value (SV) ranged from 191.00 KOH/g of oil. Groundnut oil has the highest SV and soybean oil gave the least SV; iodine values (IV) are in the range of 124.4-51.20, Wij's; 31.76-6.83 values were obtained for viscosity; acid value (AV) were obtained as 5.54-4.2 and specific gravity (SG) were found as 1.01276-0.86.Allthese concentrations were within the limits of the accepted values by regulatory bodies. Hence these oils were safe for consumption.