Assessment of trace elements in Iranian kefir samples by using ICP-OES technique

Abstract

ABSTRACT In this research, levels of 12 trace elements (Al, Zn, Cd, Ni, Hg, Pb, Co, Cr, Se, Fe, As and Mn) were measured in Iranian kefir samples by using ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) method. Based on our findings, the maximum and minimum averages of essential elements were related to Fe (423 ± 146 µg/kg) and Se (not detected or ND), respectively, and the maximum and minimum averages of toxic elements were related to As (13.3 ± 4.68 µg/kg) and Hg (ND), respectively. Based on the amount of fat in the kefir samples, the highest mean values of toxic and essential elements was related to As (15.9 ± 5.25 µg/kg) and Fe (466 ± 177 µg/kg) in high-fat kefir samples, respectively. In addition, the correlation between the amount of fat and elements in the samples was shown with a multivariate principal component analysis (PCA). Based on the obtained results, the amount of trace elements in kefir samples was lower than the existing standards (Cd = 10, Pb = 20, Al = 500, Hg = 20, As = 140, Mn = 100 and Fe = 2700 µg/kg). Also, in reviewing the results by PCA analysis, the differences and similarities between the type and amount of toxic elements and essential elements in kefir samples have been shown. Finally, based on the obtained results, it can be concluded that the consumption of this food item can be safe due to the low level of elements below the acceptable limit.