Contamination of cheese by polycyclic aromatic hydrocarbons in traditional smoking. Influence of the position in the smokehouse on the contamination level of smoked cheese

This paper sets out to determine the polycyclic aromatic hydrocarbon (PAH) contamination degree of a traditionally smoked cheese: Herreño cheese, which comes from one of the Canary Islands. Its PAH profile is thoroughly studied by means of gas chromatography-mass spectrometry in SIM mode, and compared with that of an unsmoked cheese. Furthermore, a parameter not previously studied is evaluated, namely the influence of the position of the individual cheeses in the smokehouse on their PAH contamination level. Heavy PAH, among which are included most of the carcinogens, are very scarce and their concentrations low. In fact, benz[a]anthracene, together with chrysene+triphenylene, are the only heavy PAH detected in all of the smoked samples studied. The concentration of benzo[a]pyrene, detected only in 1 of the samples, is below the limit established in Spain for the rind of smoked cheese. In contrast, high concentrations of light PAH have been found, especially of naphthalene and its alkyl derivatives, whose effect on human health is not yet well established. The results derived from the analysis of the PAH profile suggest the potential usefulness of certain ratios between some pairs of PAH (phenanthrene/anthracene, naphthalene/acenaphthylene) to provide information on the PAH contamination source. Furthermore, differences have been found, depending on the position of the cheeses in the smokehouse, those placed in the path followed by the smoke being more contaminated. Therefore, the findings of this study could help in improving the design of smokehouses, to decrease the PAH contamination degree of smoked cheese.