تعيين ميزان فلزات سنگين در كشك مايع و خشك توليدي در كارخانجات استان خراسان رضوي

Determining of Heavy Metals Content in Produced Liquid and Dry Curdle in Khorasan-E- Razavi Industries

Heavy metals composition of foods is of interest because of their essential or toxic nature. Liquid curdle may be manufactured from dried curdle or pasteurized yoghurt. The concentrations of heavy metals are probably more in curdle produced via the first method, so this research was carried out to study and compare these methods. Twenty four curdle samples were analyzed for Fe, Cu, Zn, As, Pb, Cd and Ca by atomic absorption spectrophotometer. The average metals concentration was respectively 3.22, 33.55, 8.19, 3.54, 0.21, 0.1 and 1146 ppm. Cu and Fe concentrations were found to be more than the permitted limits in national standard. The concentration of Pb in samples manufactured from dried curdle was more than the permitted limit in Codex standard. Arsenic concentration was more than the permitted limit in both methods. The concentrations of As, Cu, Zn & Fe in the samples manufactured from dried curdle were more than the other method and the differences were statistically significant (p<0.05). We can conclude that the high concentration of heavy metals in samples manufactured from dried curdle is due to the process conditions, specially drying and storage parameters.