Assessment of Element Partitioning in Dairy Products: Application of Three Stage Sequential Fractionation Scheme and Metal Determination by ICP-OES

Abstract

Background: Availability of minerals in foodstuff depends on their physicochemical form. This study was conducted to determine the concentration and partitioning of Fe, Cu, Zn, Mn, Mg, Ca, Cr, Ni, Mo, Al, Ba, Pb, Sn, V, Co and Cd in yogurt, ayran, kefir, ice-cream, cream, and pudding. Methods: Assessment of element partitioning was carried out by applying a sequential fractionation scheme in dairy products. The protein, lipid and serum fractions of each sample were separated successfully and determination of elements was achieved using inductively coupled plasma optic emission spectrometry. Results: The total amount of elements varied between dairy products. On the other hand, partitioning tendency of elements between fractions showed similarities. Zn, Mg and Ca were mainly found in serum fractions within the range of 56.8 - 80.6 %, 87.0 - 96.6 % and 85.2 - 96.6 %, respectively. Additionally, higher proportions of Fe and Cu were detected in protein fraction. Conclusion: It was concluded that kefir is a good source of elements in dairy products and the obtained data provides information for availability. Keywords: Dairy product, fractionation, ice cream, kefir, minerals, nutrition, yoghurt.