Determination and risk assessment of ptaquiloside from bracken fern in Korea using monitoring data

The bracken fern (BF; Pteridium aquilinum), which is widely consumed in East Asia, is classified as possibly carcinogenic to humans (Group 2B) by the International Agency for Research on Cancer owing to its ptaquiloside (PTA) content. In this study, we developed and validated an LC-MS/MS method for quantifying PTA and its metabolite, pterosin B (PtB), in BF. The method had a detection limit of 0.0084 mg/kg and precision (RSD%) below 3%. Monitoring of regional and commercial products revealed PTA and PtB concentrations of 0.04-506.00 and 16.54-288.36 mg/kg, respectively. Notably, PTA concentrations decreased by up to 72.4% following domestic cooking processes such as boiling and pan-frying. The mean dietary exposure in the total population was estimated at 381.8 ng/kg bw/day. MOE values were within tolerable levels only for mean exposure in specific age groups (3-5, 12-18 and 19-29 years), with the lowest values observed in adults aged 50 years and older. The integration of exposure modelling with cooking reduction factors showed that thermal processing can effectively reduce PTA concentrations and serve as a practical risk-mitigation measure. These findings emphasise the importance of applying appropriate cooking practices to reduce PTA exposure.