To make the seed edible, the saponin must be removed, traditionally done by hand-scrubbing. Saponins can't be digested and can sometimes cause intestinal damage or reduce intestinal absorption of nutrients. Because they're toxic to various organisms, saponins are being studied as for their insecticidal, antibiotic, fungicidal, and pharmacological properties. The pharmacological interest in saponins is their ability to induce changes in intestinal permeability, which may aid patients in absorbing drugs. It has a high content of calcium, phosphorus, and iron and is low in sodium.
Wheat is the only cereal grain that comes close to matching quinoa's protein content.
Quinoa also has a good amount of methionine and cystine, making it a perfect compliment for legumes, which are low in these essential amino acids. The leaves of the quinoa plant can also be eaten. While the seeds of quinoa are considered to be the edible form of the plant, the leaves and sprouts can also be eaten raw or cooked and provide a substantial amount of nutritive value.