Reduction of pyrrolizidine alkaloids by cooking pre-treatment for the petioles and the young spikes of Petasites japonicus

抄録

This study aimed to find an effective protocol as a cooking pre-treatment for the petioles and young spikes of Petasites japonicus to reduce their contents of pyrrolizidine alkaloids (PAs), a type of natural toxin in plants such as the Asteraceae and Boraginaceae families. After determining the most common cooking pre-treatment methods for petioles and young spikes of Petasites japonicus from a survey of recipes, various treatments were examined for their effectiveness at reducing PAs. It was concluded that both boiling and soaking processes were important for the reduction of PAs in pre-treatment of cooking the petioles and the young spikes of Petasites japonicus, and that a longer soaking time had a greater effect in reducing PAs. PAs in the petioles and young spikes decreased to less than 50% of the original amount in 1 h and 6 h, respectively during soaking after boiling (and peeling).