Assessment of various conditions for the simultaneous determination of US EPA and EU priority PAHs in coffee samples and their PAHs consumption risk.

The optimal conditions for simultaneous determination of the U.S. Environmental Protection Agency (US EPA) and European Union (EU) priority polycyclic aromatic hydrocarbons (PAHs) in coffee beans and coffee brews were developed. The QuEChERS (quick, easy, cheap, effective, rugged and safe) technology combined with high performance liquid chromatography - temperature-controlled fluorescence detection and gas chromatography - tandem mass spectrometry were used in the investigation. PAHs could be determined in commercially available green coffee beans (possibly caused by environmental contamination), and their PAHs content increased with the degree of roasting. Coffee beans brewed with the coffee machine released more PAHs into their brews than those brewed with the drip bag. The PAHs consumption risk of the brewed coffee samples was not high due to their low PAH level. Nevertheless, the methods of roasting and brewing and the amount of drinking could still be considered to reduce the intake of PAHs.

Optimization of QuEChERS and high performance liquid chromatography-fluorescence detection conditions to assess the impact of preparation procedures on EU priority PAHs in coffee samples and their PAHs consumption risk.

The good performance conditions for determination of EU priority PAHs in coffee samples were established to evaluate the effects of roasting degree on the PAHs in coffee beans and the brewing methods on the PAHs transfer from coffee beans to their brews. The consumption risk of the PAHs in coffee products was also assessed. The PAHs levels of the roasted coffee beans were in the order: 923.65 ng/g (dark roast) > 132.20 ng/g (medium roast) > 69.28 ng/g (light roast). Compared with general brewing with the drip bag (PAHs content, 0.30-0.62 ng/mL in coffee brews), the coffee machine brewing (set at 4 bar) induced higher PAHs release into coffee brews (PAHs content, 0.36-2.14 ng/g). The PAHs amounts of the commercial brewed and canned coffee products were 0.32-1.23 ng/g and 0.16-0.46 ng/g, respectively. The consumption risk of the PAHs in the coffee brews and products is a low level of concern.