Changes and Relationships Between PCB 126, PCB 169 and Macroelement Concentrations During the Technological Process of Selected High-Fat Dairy Products

Dairy products are an important source of macroelements in the human diet but may also contain lipophilic contaminants such as dioxin-like polychlorinated biphenyls (dl-PCBs). This study investigated changes in the concentrations of PCB 126 and PCB 169 and selected macroelements (Ca, K, Na and Mg) during the production of butter, fat blend and cream (18% fat). Samples collected at intermediate and final stages of production were analysed. PCB congeners were determined by GC-MS, whereas macroelements were analysed by ICP-AES. Butter production increased PCB 126 and 169 concentrations on a wet weight basis, while their concentrations decreased on a lipid basis. The greatest reduction was observed during fat blend production due to the addition of sunflower oil, whereas the smallest reduction occurred during cream production. Changes in PCB 126 and 169 concentrations were accompanied by decreases in macroelement concentrations, particularly calcium. Strong negative correlations (p < 0.05) were found between PCB congeners and macroelements, whereas PCB 126 and PCB 169 showed strong positive correlations. These results indicate that dairy processing influences both PCB congener distribution and the macroelement composition of high-fat dairy products.