Comparison of soluble dietary fibers from various quinoa microgreens: Structural characteristics and bioactive properties

[Display omitted] •Soluble dietary fibers from various quinoa microgreens (QMSDFs) were firstly studied.•All QMSDFs were rich in pectic-polysaccharides, e.g., HG and RG I pectic domains.•All QMSDFs exerted remarkable antioxidant, prebiotic, and immunoregulatory effects.•Their low molecular weights might partially contribute to their high bioactivities.•QMSDFs had good potentials to be developed as value-added healthy products. Quinoa (Chenopodium quinoa Willd.) microgreens are widely consumed as healthy vegetables around the world. Although soluble dietary fibers exist as the major bioactive macromolecules in quinoa microgreens, their structural characteristics and bioactive properties are still unclear. Therefore, the structural characteristics and bioactive properties of soluble dietary fibers from various quinoa microgreens (QMSDFs) were investigated in this study. The yields of QMSDFs ranged from 38.82 to 52.31 mg/g. Indeed, all QMSDFs were predominantly consisted of complex pectic-polysaccharides, e.g., homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains, with the molecular weights ranged from 2.405 × 104 to 5.538 × 104 Da. In addition, the proportions between RG I and HG pectic domains in all QMSDFs were estimated in the range of 1: 2.34–1: 4.73 (ratio of galacturonic acid/rhamnose). Furthermore, all QMSDFs exhibited marked in vitro antioxidant, antiglycation, prebiotic, and immunoregulatory effects, which may be partially correlated to their low molecular weights and low esterification degrees. These findings are helpful for revealing the structural and biological properties of QMSDFs, which can offer some new insights into further development of quinoa microgreens and related QMSDFs as value-added healthy products.