title: GC-MS Profiling of Triterpenoid Saponins from 28 Quinoa Varieties (Chenopodium quinoa Willd.) Grown in Washington State.
abstract: Quinoa (Chenopodium quinoa Willd) contains 2 to 5% saponins in the form of oleanane-type triterpenoid glycosides or sapogenins found in the external layers of the seeds. These saponins confer an undesirable bitter flavor. This study maps the content and profile of glycoside-free sapogenins from 22 quinoa varieties and 6 original breeding lines grown in North America under similar agronomical conditions. Saponins were recovered using a novel extraction protocol and quantified by GC-MS. Oleanolic acid (OA), hederagenin (HD), serjanic acid (SA), and phytolaccagenic acid (PA) were identified by their mass spectra. Total saponin content ranged from 3.81 to 27.1 mg/g among the varieties studied. The most predominant sapogenin was phytolaccagenic acid with 16.72 mg/g followed by hederagenin at 4.22 mg/g representing the ∼70% and 30% of the total sapogenin content. Phytolaccagenic acid and the total sapogenin content had a positive correlation of r2= 0.88 (p < 0.05). Results showed that none of the varieties we studied can be classified as "sweet". Nine varieties were classified as "low-sapogenin". We recommend six of the varieties be subjected to saponin removal process before consumption. A multivariate analysis was conducted to evaluate and cluster the different genotypes according their sapogenin profile as a way of predicting the possible utility of separate quinoa in food products. The multivariate analysis showed no correlations between origin of seeds and saponin profile and/or content.
authors.affiliation: School of Food Science, Washington State University , Pullman 99164, Washington, United States.
authors.forename: Ilce G
authors.initials: IG
authors.lastname: Medina-Meza
authors.affiliation: School of Food Science, Washington State University , Pullman 99164, Washington, United States.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Aluwi
authors.affiliation: The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University , Pullman 99164, Washington, United States.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Saunders
authors.affiliation: School of Food Science, Washington State University , Pullman 99164, Washington, United States.
authors.forename: Girish M
authors.initials: GM
authors.lastname: Ganjyal
mesh_terms: D027465:Chenopodium quinoa / Q000737:chemistry* / Q000145:classification; D008401:Gas Chromatography-Mass Spectrometry; D010936:Plant Extracts / Q000138:chemical synthesis / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry*; D014861:Washington
chemical_list: D010936:Plant Extracts; D012503:Saponins; D014315:Triterpenes
keywords: GC−MS; multivariate analysis; quinoa; total saponin content; triterpenoid sapogenins