Comparison of the nutritional composition and the concentrations of various contaminants in branded and private label yogurts

This study was aimed at comparing the nutritional and contaminant profiles among several of the most consumed trademarks of yogurts in Catalonia (Spain). The nutritional composition, the levels of aflatoxin M1 (AFM1), as well as the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and various heavy metals were determined in six of the main trademarks of yogurts in Catalonia. To assess potential quantitative differences, a critical comparison between “private label” yogurts and branded yogurts was performed. AFM1 was detected in six samples (33%), while the most detected heavy metals were As, Cd, and Pb. Slight differences were found between yogurt samples in some minerals and trace elements including Ba, Ca, Cu, Cr, Fe, K, and Mg. The WHO-TEQ values ranged between 0.006-0.008 and 0.003-0.012 ng/kg, for PCDD/Fs and PCBs, respectively. To the best of our knowledge, this is the first study providing a transversal approach on the occurrence and co-occurrence of the major chemical contaminants in yogurt with a critical comparison between trademarks. The results do not show relevant differences on the nutritional composition, or on the levels of the assessed contaminants (chemicals and AFM1) between “private label” and branded plain yogurts.