Citric acid

Citric acid is notable for histamine. Clear on tyramine, salicylate, sucrose, FODMAPs, lactose, oligosaccharides, sorbitol, fructose, nickel, oxalates and gluten.

Citric acid contains only low levels of histamine. Citric acid is not squeezed from lemons. Almost all of it is made by fermenting sugar with the mould Aspergillus niger and purifying the acid out of the broth - which is why it appears on histamine elimination lists at all, as a fermentation product rather than a fruit extract. The purified acid carries no amines. Two things are worth knowing beyond that, at the weight the evidence gives them: the production strains are screened for mycotoxins because most of them can make some, and purification is what stands between that and the food; and a small series of case reports has described inflammatory reactions to the manufactured additive in people who tolerate citrus fruit. Four cases is a signal to be aware of, not a demonstrated effect. Amounts vary by brand and recipe, so always check the label of the exact product.