ANALYSIS OF CONCENTRATIONS OF RISK AND TOXIC ELEMENTS IN SHEEP MILK FROM AREA OF SLOVAKIA WITH POTENTIALLY UNDISTURBED ENVIRONMENT

Abstract

Concentration of toxic metals in milk, especially in industrial regions, may serve as a direct bioindicator of the quality of milk, which is an important food in human diet. The aim of this study was to find actual contamination of selected area of Slovakia and to determine the effect of lactation stages on the concentration of risk and toxic elements in sheep´s milk of Tsigai breed. Monitoring of environment was performed by sampling of soil, feed, and milk samples from 400 ewes. Selected elements in feed and milk were detected using the AAS-HG, AES-ICP, AAS-ETA, AAS-AMA, and AAS-F and in soil samples by ICP-OES. Concentrations of toxic elements (As, Hg, Pb, Ni) were found in the soil samples, which corresponded to MRL, and their content was not reflected in the samples of feed and milk of sheep and were below the LOQ. The effect of lactation stage was statistically significant only in case of Ca (P<0.05), where a significant increase in concentration of this element was found throughout the lactation period. A statistically significant increase of concentrations of Se, Mg, Zn and Fe (P<0.05) in sheep milk was recorded only in the late stage of lactation. Pearson´s correlation analysis showed a several very strong and positive correlation relationships in individual lactation stages of sheep. The very low concentrations, below LOQ of selected toxic elements in milk confirmed, that level of contamination of the selected area of Slovakia is very low, and milk from this area of Slovakia is in good hygienic quality and it is safety for direct consumption or for further processing.