CONCENTRATIONS OF METALS IN VEGETABLE EDIBLE OILS

Concentrations of Na, K, Ca, Mg, Cu, Zn and Fe as well as the indices of acidity and peroxides have been determined in several Spanish edible oils. For Cu and Fe, respectively, 18.3% and 2.8% of the samples showed higher values than the maximum permitted by FAO/WHO. However, there were no samples that exceeded the maximum values established by the Spanish directorate for these two metals. Maximum values for the indices of acidity and peroxides established by the Spanish directorate were exceeded in 17% and 21% of the samples overall. Olive oil had a higher number of samples that exceed the maximum values of the Spanish directorate than other analysed oils. The ratio Na/K was always higher than unity, which means that the oils had been subjected to a refinement process. Strong correlations between Na and K and between Ca and Mg were found in all the types of oil studied. Also, moderate correlations between the acidity index and the concentration of Fe, and between the indices of acidity and peroxide, have been observed.