Metabolic fingerprinting unveils quinoa oil as a source of bioactive phytochemicals.

Quinoa is a pseudo-cereal with high phytochemical contents with proven biological and nutritional significance. In recent decades several breeding programmes have introduced new and traditional quinoa varieties to North America and other non-traditional quinoa regions, raising questions regarding variability in their secondary metabolite profiles. In this work, we have fingerprinted 28 quinoa varieties cultivated in Washington State, focussing on the poorly investigated oil fraction. We found variability in both phenolics and carotenoid contents, which is reflected in different antioxidant capacities, as measured by FRAP and DPPH. Fatty acid profiles show significant differences in palmitic acid and long-chain fatty acids. Finally, conspicuous amounts of phytosterols and squalene were found. Through factor analysis, we classified the quinoa varieties into two groups: a first comprising varieties with higher phytochemical and PUFA contents and a second group, with higher linolenic and long-chain fatty acid contents. Both groups may be suitable for potential food applications.

Impacts of Scarification and Degermination on the Expansion Characteristics of Select Quinoa Varieties during Extrusion Processing.

Extrusion of 2 quinoa varieties, Cherry Vanilla and Black (scarified and unscarified) and a mixed quinoa variety, Bolivian Royal (scarified and degermed) were studied for their extrusion characteristics. A corotating twin-screw extruder with a 3 mm round die was used. Feed moisture contents of 15%, 20%, and 25% (wet basis) were studied. The extruder barrel temperature was kept constant at 140 °C and screw speeds were varied from 100, 150, and 200 revolutions per minutes. Process responses (specific mechanical energy, back pressure, and torque) and product responses (expansion ratio, unit density, and water absorption index/water solubility index) were evaluated. The degermed Bolivian Royal showed the highest expansion in comparison to all other varieties, attributed to its significantly low levels of fat, fiber, and protein. The scarified Cherry Vanilla resulted in the lowest expansion ratio. This was attributed to the increase in the protein content from the removal of the outer layer. The results indicate that all the varieties performed differently in the extrusion process due to their modification processes as well as the individual variety characteristics.

GC-MS Profiling of Triterpenoid Saponins from 28 Quinoa Varieties (Chenopodium quinoa Willd.) Grown in Washington State.

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.