Quinoa (Chenopodium quinoa) is a grain crop which was anciently used by the Andean Indians. It is frost and drought resistant and grows well at high altitudes. Quinoa has an excellent amino acid composition and ranges from 10-18% protein. However, Quinoa seeds contain high amounts of saponins which are located in the pericarp. Saponins, which have a bitter, soapy taste, are water soluble and can be removed by vigorously washing the seeds in water. The two varieties of Quinoa used in this study are C. quinoa var. appelawa, a variety high in saponin content, and C. quinoa var. sajama amaranthiform, a saponin free variety. The purpose of this study is to analyze the location of saponins in washed and unwashed C. quinoa var. appelawa, and to analyze the differences between the seed surface morphologies of C. quinoa var. appelawa and C. quinoa var. sajama amaranthiform. The Quinoa seed surface consists of a layer of large cells that are sack-like in appearance. In C. quinoa var. appelawa, these cells are durable and in tact after the seed is removed from the fruit, whereas, in C. quinoa var. sajama amaranthiform, the cells are disrupted and deflated. In C. quinoa var. appelawa, spherical structures are found inside these cells in unwashed seeds and are relatively absent in washed seeds. This suggests that these spherical structures are saponins. However, these spherical structures are found both inside and outside the disrupted cells on the surface of C. quinoa var. sajama amaranthiform seeds. One explanation for their presence in C. quinoa var. sajama amaranthiform is that the fragile saponin containing cells on the seed surface may slough off easily in the dehulling process giving the seeds the saponin free characteristic.

Key words: Chenopodiaceae, Chenopodium quinoa, Quinoa, saponin, seed surface morphologies, SEM