Measurement of zinc, copper, lead and cadmium in a variety of yogurt and Dough available on the market by voltammetry

Food products contain various chemicals, including essential and nutritious elements, toxic and harmful elements, among which dairy products are widely consumed among people and it is necessary to check the number of elements such as zinc and copper that are essential for the vital activities of the body and toxic heavy metals such as cadmium and lead that enter dairy products due to environmental pollution, need to be controlled and monitored.

To investigate the amount of zinc, copper, lead and cadmium metals in yoghurt and doogh, the products of 12 high-consumption factories in Tehran, which included 9 brands of yoghurt and 9 brands of doogh, were collected by Differential Pulse Anodic Stripping Voltammetry method due to High sensitivity and selectivity Dry Ash method was used to prepare the sample and the samples were injected into the tube of the machine and to draw the calibration curve, the method of adding the standard edition (three times in each step) was used. The average concentration of zinc was processed by using SPSS software.

For yoghurt and doogh the average concentration of zinc was 27.08 ± 4.56 and 8.72 ±1.53 µg/l respectively, and for copper 4.94± 0.70 and 3.21± 0.59 µg/ l, and for cadmium 6.34 ± 0.73 and 4.05± 0.64µg/l and for lead was 4.84 ± 0.69 and 3.09 ± 0.62 µg/l, respectively that according to the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) and the USDA, the concentration of all metals was below the permitted level and there was no significant difference between the concentrations of yoghurt and doogh samples. (pvalue>0.05)

Considering the increasing consumption of yoghurt and doogh dairy products in the household food basket and its serious role in daily nutrition, therefore, it seems necessary to study and control the quality of zinc and copper and lead and cadmium micronutrients contaminants.