Even rust, FeOOH (s), forms water - soluble complexes in alkaline solution with EDMA and can be washed out of the wood. (scienceinschool.org)
However, any plant protein powder will go through a similar manufacturing process — separation from the fiber by boiling in caustic alkaline solutions and then spray - drying at very high temperatures, leaving the proteins denatured and possibly toxic. (westonaprice.org)
Quinoa brought to market has already been rinsed of much of its saponins, as otherwise it would be quite unpalatable (this procedure is done with a strong alkaline solution). (vegkitchen.com)