Heavy metal residues in milk and some dairy products with insight into their health risk assessment and the role of Lactobacillus rhamnosus in reducing the lead and cadmium load in cheese

Abstract

Heavy metals were analyzed in buffalo's milk and some dairy products assembled from different dairy farms, supermarkets, and vendors in Mansoura, Egypt. The mean concentrations (mg/kg wet weight) of the heavy metals detected in raw milk, Kareish cheese, processed cheese, and milk powder were 0.0014, 0.0378, 0.0022, and 0.0204, respectively for mercury; 0.012, 0.0764, 0.052, and 0.120, respectively for arsenic; 0.1016, 0.2924, 0.1256, and 0.3352, respectively for lead; 0.07, 0.1172, 0.0576, and 0.1252, respectively for cadmium; 0.1044, 0.174, 0.1016, and 0.208, respectively for chromium; and 0.0656, 0.188, 0.1272, and 0.2496, respectively for copper. The probiotic Lactobacillus rhamnosus was incorporated into soft cheese as an attempt for reducing lead and cadmium whose concentrations were diminished by 81.5% and 74.5%, respectively within 48 h at 4 °C. The study concluded that although the maximum limit of Pb and Cd has been exceeded in 44% to 68% of the dairy products tested, the health risk assessment indices comprising Estimated Daily Intakes, Provisional Tolerable Daily Intakes, Target Hazard Quotient, and Hazard Index indicated no potential health risk upon consumption of such dairy products analyzed. The study also suggested the use of Lactobacillus rhamnosus probiotic for minimizing lead and cadmium levels in dairy food.