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 r = 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.

Analysis of saponin composition and comparison of the antioxidant activity of various parts of the quinoa plant (Chenopodium quinoa Willd.)

“…Quinoa bran (QB) had the highest amounts of OA, HD, and PA, while quinoa leaves (QL) had the lowest sapogenin contents. In this work, PA was the most commonly found sapogenin in the various parts of quinoa plant grown in Korea, which is consistent with results of a previous study on sapogenin content in quinoa seeds grown in the United States (Medina‐Meza et al, ). On the other hand, Mastebroek, Limburg, Gilles, and Marvin () found that hederagenin (HD) was the major sapogenin found in leaves and oleanolic acid (OA) was in seeds.…”

Acid hydrolysis of saponin‐rich extracts of quinoa, lentil, fenugreek and soybean to yield sapogenin‐rich extracts and other bioactive compounds

“…3,4 Saponins, traditionally considered as antinutrients, have been under intense research in recent years due to their proven biological activity, such as immunostimulatory, hypocholesterolemic, antitumor, anti-inflammatory, antibacterial, antiviral, antifungal, or antiparasitic activity. [5][6][7] Recently, the anti-inflammatory activity 28 1-12 100 3 N H 2 SO 4 in dioxane/water 24 72 85 2 N HCl in methanol 29 Panax notoginseng 3 55 Acetic acid 25% 30 Medicago 8 2 N HCl in methanol 27 Dioscorea zingiberensis 1-7 120 H 2 SO 4 31 Chenopodium quinoa 2 90 1 N HCl in dioxane/water 32 2 110 6 N HCl 33 2 100 2 N HCl in aqueous methanol 34 Legumes 3 refluxed HCl in methanol 5% 35 Lentil seed 3 refluxed Acetyl chloride in methanol 5% 36 Primulaceae plants 4 refluxed 2 N HCl in ethanol 37 of triterpenoid saponins from soybean was demonstrated in macrophages by downregulation in nitric oxide production. 8 Similarly, triterpenoid quinoa saponins have been demonstrated to inhibit the release of inflammatory cytokines, and to decrease the production of inflammatory mediators.…”

Seed proteins mining for development, nutrition and germination using comparative proteomics analysis in quinoa（Chenopodium quinoa willd.)

“…The DEP, AUR62025699-RA, was annotated as β-amyrin 28-oxidase, a saponin bio-synthesis enzyme. Quinoa contains 2 to 5% saponins, producing an undesirable bitter avor, found in the external layers of the seeds or leaves (Medina-Meza et al, 2016). According to their saponin content, quinoa varieties have been classi ed as "sweet" (free or less than 0.11 g/100 g DW) and "bitter" varieties (more than 0.11 g/100 g DW) (Vega-Galvez et al, 2010).…”

“…According to their saponin content, quinoa varieties have been classi ed as "sweet" (free or less than 0.11 g/100 g DW) and "bitter" varieties (more than 0.11 g/100 g DW) (Vega-Galvez et al, 2010). Given the associated bitterness and toxicity of saponins, quinoa is treated to reduce saponin levels by washing, dehulling, or thermal processing (Gomez-Caravaca et al, 2014;Medina-Meza et al, 2016). The process is costly and water-intensive, also can reduce the nutritional value of the seeds (Zurita-Silva et al, 2004).…”

“…Thus, the development of saponin-free lines is a major breeding objective in quinoa (Zurita-Silva et al, 2014). Oleanane-type triterpenes are the major saponin components in quinoa (Medina-Meza et al, 2016). The enzyme, β-amyrin 28-oxidase, is essential for oleanane-type saponin biosynthesis (Han et al, 2013, Jo et al, 2017.…”