Chemical composition, metals content and pesticide residues in raw, pasteurized and UHT milk and their dietary intake

ABSTRACT

Chemical composition, metal contents and pesticide residues were determined in raw, pasteurized and UHT [Ultra High Temperature] milk samples collected from local markets in Cairo Governorate, Egypt. Fat, T.P. [Total Protein], ash, lactose and T.S. [Total Solids] contents were [3.50, 3.20, 0.71, 4.10 and 11.40%], [3.00, 3.50, 0.80, 4.65 and 11.50%], and [3.00, 3.40, 0.80, 4.44 and 11.50%] in raw, pasteurized and UHT milk, respectively. Levels of Zn, Fe, Cu, Mn, Cr, Ni, Co, Pb, Cd and Sn were [3.59, 0.62, 0.17, 0.06, 0.03, 0.036, 0.032, 0.032, 0.025 and 0.002 mg/kg], [3.11, 0.55, 0.15, 0.041, 0.030, 0.030, 0.030, 0.021, 0.022 and 0.002 mg/kg] and [3.11, 0.60, 0.180, 0.050, 0.020, 0.030, 0.030, 0.020, 0.020 and 0.002 mg/kg] in raw, pasteurized and UHT milk, respectively. Organochlorine pesticides [HCB, lindane, aldrin, heptachlor, heptachlor epoxide, chlordane, endrin and DDT metabolites] were detected in raw milk at levels higher than the tolerance limits. However, these chemicals were detected in pasteurized milk at slightly higher levels and in UHT milk at levels lower than the tolerance limits. On the other hand, non of raw, pasteurized and UHT milk revealed the presence of organophosphorus pesticides [malathion, profenofos, pirmiphos-methyl and dimethoate]. To assess any possible risks to consumers of milk, dietary intakes have been estimated using the mean concentration of various metals and pesticide residues in this monitoring. Data showed that, daily intake of the investigated metals and pesticides in milk were lower than the recommended levels except that Pb and Cd are higher than it