Detection of polycyclic aromatic hydrocarbons in smoked buffalo mozzarella cheese produced in Campania Region, Italy

Concentrations, influencing factors, risk assessment methods, health hazards and analyses of polycyclic aromatic hydrocarbons in dairies: a review

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in dairies has been widely reported. Consumers may be overly exposed to PAHs through dairies causing health risks. Hazards can be reduced by controlling influencing factors in the full-chain of dairy production. This review briefly introduces research trends and analytical methods concerning PAHs in dairies. Additionally, this review discusses influencing factors of PAH concentrations in various dairies to avoid PAHs' formation and accumulation during manufacture. Relevant regulations are referred to and the reported risk assessment methods are summarized. Furthermore, indicators of health risks including TEQBaP, the number and the rate of over-standard are calculated based on PAH concentrations. Through analyses, we find PAH and BaP contamination in dairies are complex problems depending on environment, processing and storage. There was a significant correlation between fat contents and PAH concentrations. Results of infant formula in certain research were worrying and those of smoked cheeses are remarkably high indicating the dangerous smoking process. It is significant to monitor PAHs and calculate TEQBaP from meadows to feeders. Moreover, the existing regulations are insufficient and need strengthening. The data and discussions in this review contribute to worldwide Big Data, further scientific investigation and regulations for PAHs in dairies.

Polycyclic Aromatic Hydrocarbons in Foods: Biological Effects, Legislation, Occurrence, Analytical Methods, and Strategies to Reduce Their Formation

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds comprised of carbon and hydrogen molecules in a cyclic arrangement. PAHs are associated with risks to human health, especially carcinogenesis. One form of exposure to these compounds is through ingestion of contaminated food, which can occur during preparation and processing involving high temperatures (e.g., grilling, smoking, toasting, roasting, and frying) as well as through PAHs present in the soil, air, and water (i.e., environmental pollution). Differently from changes caused by microbiological characteristics and lipid oxidation, consumers cannot sensorially perceive PAH contamination in food products, thereby hindering their ability to reject these foods. Herein, the occurrence and biological effects of PAHs were comprehensively explored, as well as analytical methods to monitor their levels, legislations, and strategies to reduce their generation in food products. This review updates the current knowledge and addresses recent regulation changes concerning the widespread PAHs contamination in several types of food, often surpassing the concentration limits deemed acceptable by current legislations. Therefore, effective measures involving different food processing strategies are needed to prevent and reduce PAHs contamination, thereby decreasing human exposure and detrimental health effects. Furthermore, gaps in literature have been addressed to provide a basis for future studies.

p-Cresol in cheese: Is it a flavouring compound or chemical contaminant?

p-Cresol has been identified as a flavouring compound in cheeses; however, scientific studies have already identified p-cresol as a potential chemical contaminant in environmental matrices. Thus, the objective of this study was to evaluate four traditional methods for extracting p-cresol from cheese samples in order to validate the best method, and finally to apply it to five cheese samples with different origins, processing and ripeness times. The analyses were performed by gas chromatography-mass spectrometry after derivatisation of p-cresol with anhydride acetic and pyridine. Better results were achieved by the QuEChERS method, which showed recovery higher than 80%, relative standard deviation lower than 16%, limit of quantification of 5 μg kg^-1 and linearity between 5 and 400 μg kg^-1 with R² 0.99. p-Cresol was quantified in almost all of the samples analysed at different concentration levels, which were in an increasing order at μg kg^-1: Cheddar (< LOQ), Parmesan (8 ± 0.7), Gorgonzola (103 ± 14), smoked Provolone (365 ± 28) and barbecue cheese (1001 ± 187). Although no maximum residue limit has been established for p-cresol in food, the results suggest that cheeses exposed to charcoal combustion notably increase the p-cresol levels and may represent a hazard to human health, especially in risk groups such as patients with chronic kidney disease who have serious problems with p-cresol.

Study of polycyclic aromatic hydrocarbons generated from fatty acids by a model system

BACKGROUND

The characteristics of carcinogenic polycyclic aromatic hydrocarbons (PAHs) produced from various fatty acids, as important components of fats and oils, at high temperature are still little known. The reason is because the existing data are from experiments conducted in complex food systems. In this study, 12 PAHs produced from nine fatty acids, representing saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), were investigated in a model system heated at 98, 165 and 240 °C.

RESULTS

SFAs can with difficulty be pyrolyzed to generate PAHs at 98 °C, but small amounts of PAHs were determined in MUFAs (44.97 µg kg^-1 ) and PUFAs (177.73 µg kg^-1 ). When the temperature reached 165 °C, there were totals of 27.59, 142.8 and 449.68 µg kg^-1 PAHs assayed in SFAs, MUFAs and PUFAs, respectively. The amounts of PAHs generated from SFAs, MUFAs and PUFAs at 240 °C were higher when compared with those of the 165 °C group (P < 0.05). With an increase of heating temperature, the proportion of PAHs with four to five rings increased. Under the same heating conditions, the concentration of PAHs in fatty acids increased with an increase in the number of double bonds.

CONCLUSIONS

More PAHs, especially carcinogenic ones with four to five rings, will be produced in fatty acids heated at higher temperature. The content of PAHs generated from fatty acids increased with an increase in the number of double bonds. This study will increase the understanding of the production characteristics of PAHs from various fatty acids under heating condition. © 2019 Society of Chemical Industry.