Toona sinensis contains nitrite, which is higher in the old leaves of Toona sinensis, and it will be poisoned if it is eaten improperly. Experiments have proved that Toona sinensis can remove more than 2/3 nitrite when scalded in boiling water for 1 minute, and it will not affect its nutritional value and color. In order to reduce the intake of nitrite, remind everyone that you can choose tender branches and leaves, which has a good taste and contains less nitrite, and the nitrite will be reduced a lot after boiling.