Editing Quinoa (section)

== Chemistry ==
In their natural state, the seeds have a coating that contains bitter-tasting [[saponin]]s, making them [[unpalatable]].<ref name="Lost crops" /><ref name="jarvis" /> Most of the grain sold commercially has been processed to remove this coating. This bitterness has beneficial effects during cultivation, as it deters birds and, therefore, the plant requires minimal protection.<ref name="AlternativeFieldCropsManual" /> The genetic control of bitterness involves quantitative [[heredity|inheritance]].<ref name="jarvis" /> Although lowering the saponin content through [[selective breeding]] to produce sweeter, more palatable varieties is complicated by ≈10% [[cross-pollination]],<ref name="Quinoa saponin">{{cite journal |last1=Masterbroek |first1=H.D. |last2=Limburg |first2=H. |last3=Gilles |first3=T. |last4=Marvin |first4=H.J. |year=2000 |title=Occurrence of sapogenins in leaves and seeds of quinoa (''Chenopodium quinoa'' Willd.) |journal=Journal of the Science of Food and Agriculture |volume=80 |issue=1 |pages=152–156 |bibcode=2000JSFA...80..152M |doi=10.1002/(SICI)1097-0010(20000101)80:1<152::AID-JSFA503>3.0.CO;2-P}}</ref> it is a major goal of quinoa [[breeding program]]s, which may include [[genetic engineering]].<ref name="jarvis" />

The [[toxicity category rating]] of the saponins in quinoa treats them as mild eye and respiratory irritants and as a low gastrointestinal irritant.<ref name="johnson">{{cite web |date=1993 |title=Quinoa |url=http://www.hort.purdue.edu/newcrop/proceedings1993/v2-222.html#Table%201 |access-date=21 May 2013 |publisher=Department of Horticulture, Purdue University; obtained from Johnson, D.L. and S.M. Ward. 1993. Quinoa. p. 219-221. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York |vauthors=Johnson DL, Ward SM}}</ref><ref name="Biopesticides">{{cite web |year=2009 |title=Biopesticides Registration Action Document: Saponins of ''Chenopodium quinoa'' |url=http://www.epa.gov/pesticides/chem_search/reg_actions/registration/decision_PC-097094_28-Dec-07.pdf |publisher=Environmental Protection Agency}}</ref> In South America, these saponins have many uses, including as a detergent for clothing and washing, and as a [[folk medicine]] [[antiseptic]] for skin injuries.<ref name="johnson" />

Additionally, the leaves and stems of all species of the genus ''[[Chenopodium]]'' and related genera of the family [[Amaranthaceae]], including quinoa, contain high levels of [[oxalic acid]].<ref name="oxalic acid quinoa leaves">{{cite journal |last1=Siener |first1=Roswitha |last2=Honow |first2=Ruth |last3=Seidler |first3=Ana |last4=Voss |first4=Susanne |last5=Hesse |first5=Albrecht |year=2006 |title=Oxalate contents of species of the Polygonaceae, Amaranthaceae, and Chenopodiaceae families |journal=Food Chemistry |volume=98 |issue=2 |pages=220–224 |doi=10.1016/j.foodchem.2005.05.059}}</ref>