Determination of polycyclic aromatic hydrocarbons in smoked and non-smoked black teas and tea infusions

This study describes the occurrence of polycyclic aromatic hydrocarbons (PAHs) in smoked tea and tea infusions, via the monitoring of benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene (PAH4) that have been chosen as indicators for the occurrence of PAHs in food by the European Food Safety Agency. The concentrations ranged from 1.2 μg/kg for benzo(b)fluoranthene to 125.0 μg/kg for benzo(a)anthracene in smoked tea leaves, and from 0.6 μg/L for benzo(a)anthracene to 1.2 μg/L for benzo(b)fluoranthene in smoked tea infusions. Benzo(a)pyrene was never detected in infusions. The concentrations in non-smoked tea leaves ranged from 0.6 μg/kg for benzo(a)anthracene to 10.8 μg/kg for benzo(b)fluoranthene. It was shown that the concentrations of benzo(a)anthracene and chrysene were higher in smoked tea than in non-smoked tea while no difference was observed for benzo(b)fluoranthene and benzo(a)pyrene. The concentrations of PAHs in tea infusions are low compared to other foodstuffs, but the migration rates from leaves into water are high (82-123%).