Pyrrolizidine Alkaloids in Tea and Dietary Exposure Assessment of Tea Intake

Pyrrolizidine alkaloids (PAs) and pyrrolizidine alkaloid N-oxides (PANOs) are secondary metabolites found in plants. 63 samples, which include green tea, lightly fermented tea, semifermented tea, and fermented tea, were tested to assess the dietary exposure risk of PAs/PANOs. We apply high-performance liquid chromatography coupled to tandem mass spectroscopy (HPLC-MS/MS) to detect the PAs/PANOs in tea. This study applies the margin of exposure (MoE) approach in dietary exposure assessment, and the MoE of 10,000 or higher would be of low exposure risk for health. Among the 25 PAs/PANOs tested, four PAs/PANOs, including Lycopsamine N-oxide, Intermedine N-oxide, Senkirkine, and Lasiocarpine, were identified in more than 10 samples. Six PAs/PANOs were simultaneously detected in a sample of fermented tea. In this research, 77.78% of detected samples contained PAs or PANOs, and the mean value is 17.67 μg/kg. Using the Monte Carlo simulation for the MoEs, there is only 0.2% probability that the MoE value is lower than 10,000. Calculated at the 50th percentile of total PAs/PANO levels, continuous tea intake exceeding 94 days results in the MoE value of less than 10,000.