Predictive models of heavy metals and toxic elements distribution during Parmigiano Reggiano cheese production

The concentration of aluminium, copper, iron and zinc were determined by ICP-AES on Parmigiano Reggiano cheese at several stages of production. On the same samples cadmium, lead, vanadium, cobalt, chromium, and molybdenum concentrations were determined by ICP-MS. These data together with quantitative data allowed to estimate the mass balance of the considered elements during the making of this Italian matured cheese. The affinity of elements for curd is variable: 90% of the zinc present in milk goes into the curd. This percentage is 68 for aluminium, 5 for vanadium, 15 for chromium, 93 for cobalt, 19 for iron and 50 for molybdenum. Both cadmium and lead seem to concentrate almost completely in curd, but their concentrations are very low in the starting milk (cadmium from non detectable to 0.23g/l; lead from non detectable to 4.91 g/l) and even after concentration in cheese the final levels do not represent a risk for consumers. A cession of copper from the cheese vat (made of copper) to cheese was documented but, even in this case, the concentration of copper is quite low (lower than 12 mg/kg in curd) and does not represent a risk for human health.