Residues behavior of some heavy metals during manufacturing of some milk products

الملخص EN

This investigation was run to study the residue behavior of some heavy metals during manufacturing of some milk products.

Samples of buffalo's milk as well as some milk products manufactured from it were analyzed for evaluation their contents of some metals that represents in 5 elements: manganese (Mn), copper (Cu), nickel (Ni), magnesium (Mg) and iron (Fe).

The buffalo's milk was obtained from a dairy shop located in Assiut city, Egypt, while the manufactured milk products were represented in cream, butter, ghee and Kareish cheese.

Before manufacturing of milk products, milk was divided into 2 portions; the first as control for estimation and the second was added by standards of the investigated metals in a concentration of 1 ppm.

All samples were digested and analyzed using ZEEnit 700P Atomic Absorption Spectrophotometer.

The obtained results showed that the milk contents of Mn, Cu, Ni, Mg and Fe were at concentrations of 2.3, 0.7, 0.07, 0.01 and 2.14 mg/kg, respectively.

With viewing to the recorded limits of International Dairy Federation (IDF), Mn, Cu and Fe were found to exceed these limits.

Mn was found to disappear from fat concentrated milk products (cream, butter and ghee), while concentrated in their by-products.

Cu concentrated in cream and butter.

Ni disappeared in ghee but concentrated in Kareish cheese.

No obvious concentration of Mg in milk products while Fe concentrated in by-products skim milk, butter milk and whey.

Although milk products contained more total metals content like in cream (3.502 mg/kg), butter (3.64 mg/kg) and ghee (4.7712 mg/kg) more than in the initial milk (5.23 mg/kg), the total metals content was more concentrated in by-products like in skim milk (7.89 mg/kg), butter milk (7.6171 mg/kg) and whey (5.206 mg/kg).

But in case of Kareish cheese, it (3.493 mg/kg) contained total metals content lower than in initial milk.

The public health significance of the examined metals, as well as, the recommended hygienic measures for human safety were discussed.