Hot topic: Bisphenol A in cow milk and dietary exposure at the farm level

Chemical hazards may enter the milk chain during primary production. The study, for the first time, investigated the occurrence of bisphenol A (BPA) levels in cow milk samples collected on the farm following manual or mechanical milking and from the cooling tank. We applied a new monitoring model based on the identification of the hazards at each stage of the milk chain to identify potential pathways for contamination along the milk chain. We evaluated exposure to BPA through milk consumption based on detected contamination levels and the temporary tolerable daily intake established by the European Food Safety Authority (EFSA). Milk samples (n = 72) were analyzed using liquid chromatography with fluorescence detection. The mean BPA concentrations were 0.757 µg/L in manually milked samples, 0.580 µg/L in mechanically milked samples, and 0.797 µg/L in milk from the cooling tank. Bisphenol A occurred in the milk chain as a result of different stages of milking, and reached the highest levels at the end of the milk chain. Although the dietary intake of BPA was below the EFSA's temporary tolerable daily intake, exposure to BPA, even at low doses, through milk consumption represents a public health concern. Therefore, to ensure milk safety, new monitoring plans should be applied based on the identification of hazards at each stage of the milk chain.

Towards Simazine Monitoring in Agro-Zootechnical Productions: A Yeast Cell Bioprobe for Real Samples Screening

Simazine is an herbicide that is able to contaminate surface waters, ground waters, and milk/dairy products, thus posing concerns in both environmental health and food safety. A yeast-based bioprobe was utilized to detect simazine in spiked real samples of livestock drinking water and raw cow's milk. Yeast aerobic respiration was taken as short-term toxicological endpoint. We carried out comparative measures of yeast oxygen consumption between simazine-spiked samples and blank samples. Percentage interference (%ρ) on yeast aerobic respiration was calculated through the comparison of aerobic respiration of simazine-exposed and non-exposed yeast cells. The method was optimized for raw cow's milk samples by using boric acid as fungistatic agent in order to avoid cellular proliferation. Overall, the results have shown that simazine can be detected up to concentrations five times below the EU legal concentration limits for drinking water (0.02 ppb) and cow's milk (2 ppb) (%ρ values of 18.53% and 20.43% respectively; %RSD ≤ 15%). Dose-effect relationships of simazine were assessed. The findings of the bioassays match reasonably well with known mechanisms of toxicity and intracellular detoxification in yeast. A correlation between fat content in milk samples and analytical performance of the bioprobe was established. Results suggest the involvement of a matrix effect, presumably due to lipid sequestration of simazine. The yeast-based bioprobe has proved to be sensitive and suitable for the detection of simazine in real samples in concentrations of interest.