Lupin flour

Lupin flour is a legume flour and carries legume GOS, and it turns up in gluten-free bakery as a protein and colour booster - so a bread bought precisely to avoid wheat can be high here. It is also a declared allergen in the EU, which is a separate matter on a separate axis.

Same reason as the FODMAP level: lupin is a pulse and carries pulse GOS. It reaches most people through gluten-free bakery, where it is added for protein - so a loaf chosen to avoid one problem can arrive carrying this one. Pulse oligosaccharides are water-soluble, and that is the practical point: the level here follows work on pulses AND on what cooking does to them, because soaking and boiling move part of them into water that is usually thrown away.

Lupin flour is a legume flour, high in nickel like the rest of the family, and it carries a separate allergen warning in the EU - two reasons to read for it rather than assume.

Lupin flour is moderate here, and the reason is a processing step that did not happen. Bitter lupins must be soaked and rinsed for days before they are edible, and that treatment takes soluble oxalate out along with the alkaloids - but the flour sold in Europe is milled from SWEET lupin varieties, bred precisely to skip that step. The debittering that would have lowered the oxalate is the one thing that did not happen to it. Judge it on the flour, not on the traditional preparation.

Lupin flour is a dry milled product, and dryness is what keeps it low - amine-producing bacteria need moisture. It is what the flour becomes that matters: a long-fermented dough is a different question from the flour it started as. The seed behind the flour was measured: Shalaby followed lupine alongside broad bean and chick pea, raw, germinated and cooked. Every amine tested was there in the ungerminated seed and rose considerably with germination, while COOKING LEFT THE SEEDS FREE OF THEM - the amines had passed into the boiling water. That is the seed and its sprout; the study measured no flour, and it reports patterns of change rather than a table, so it gives no figure in mg.

Lupin flour is low as a dry seed, and boiling lowers it further - amines leach into the water. Germination raises it instead, which is the one preparation to watch: a sprout has spent days doing what a dry seed cannot.