Ascorbic acid (vit. C synthetic)
soy flour
It may be problematic for some people.
Caution
May cause symptoms in more sensitive people. Track your own reaction.
Soy flour may contain moderate amounts of histamine. Tolerance to it varies from person to person and depends on how it is processed and its freshness.
Safer alternatives
Suitable
baking soda
Generally considered safe for most individuals with histamine intolerance.beeswax (E901)