Quantification and risk assessment of carcinogenic polycyclic aromatic hydrocarbons in retail smoked fish and smoked cheeses

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are known or potential carcinogens occurring in foodstuffs during smoking processes, among others. The European Commission (EC) has defined clear limits for benzo[a]pyrene and the total concentration of benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo [a]pyrene – known as the PAH4 group – that must not be exceeded by any food product commercialized within the European Union (EC Regulation No. 835/2011). In this work, we determined the concentrations of 16 PAHs, including the PAH4 group, in 17 retail smoked fish and 11 retail smoked cheeses from four and nine producers, respectively. To this end, we first developed a gas chromatography-mass spectrometry method for identification and quantification of PAHs in smoked food matrices and validated it intra-laboratory according to the guidelines of EC Regulation No. 836/2011. For the extraction of PAHs from foodstuffs and their further clean-up, we adopted a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) protocol, based on partitioning between acetonitrile and water, followed by dispersive solid-phase extraction using commercially available QuEChERS kits. The analyses of smoked fish revealed a fairly wide range of PAH concentrations, resulting both from differences in the type of smoked fish and different producers. Smoked sprat exhibited the highest total PAH concentration (around 100 ng/g), with acenaphthylene, phenanthrene, and fluorene contributing more than half of this amount, while the lowest PAH content (about 30 ng/g) was observed in smoked trout. None of the analyzed fish samples exceeded the EC limits for either benzo [a]pyrene or PAH4 in the corresponding product categories. While no such limits exist for the smoked cheese category, it was found smoked cheeses had much lower PAH levels compared to smoked fish, around 10 ng/g for ordinary pressed cheeses and 20 ng/g for generically designated “Brădet” cheeses, irrespective of producer. The majority PAHs in all investigated cheeses were found to be phenanthrene, naphthalene, and fluorene, while PAH4 accounted for only about 10% of total PAHs. Cancer risk assessment was performed using both margin of exposure and incremental lifetime cancer risk parameter determinations and none of the samples analyzed showed significant concern.