Chickpea

Chickpeas are the clearest demonstration of how legumes work here. The GOS dissolve into the soaking and cooking water, so canned chickpeas - drained and rinsed - measure well below the same weight cooked from dried. Aquafaba is that liquid, which means it carries what the chickpeas lost.

Chickpea: same reason as the FODMAP level, and the mechanism is visible: the GOS dissolve into the canning liquid, which is why a rinsed can measures below the same chickpeas cooked from dried. Aquafaba is that liquid - it holds the oligosaccharides. 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.

Chickpeas concentrate nickel through the same urease route as every legume, and they are eaten in quantity - a plate of hummus or a curry base is a much larger dose than a garnish.

Chickpeas are moderate, and the soaking they need anyway takes soluble oxalate into the water - the same water people are already told to throw away for other reasons. Canned chickpeas have had that done for them, and rinsing the can takes a little more. Quinteros measured that on the pulses themselves and found every cooking method lowers the soluble fraction, with microwave and industrial processing more effective than ordinary domestic cooking.

Chickpea carries amines: Shalaby found every amine tested in raw seeds of broad bean, chick pea and lupine, and in the chickpea histamine rose gradually as the seed germinated — the only one of the three where it climbed steadily instead of fluctuating. Sprouted is the higher form. Cooking works the other way: the seeds came out free of amines, which had passed into the boiling water, so boiling and draining is the lower form. The paper reports the pattern and not a milligram figure.