Structure, Physicochemical, and Functional Properties of Dietary Fiber Extracts Obtained from <italic>Agriophyllum squarrosum</italic> Seed and Quinoa

It was of great significance to explore new dietary fiber resources with excellent functional activity from available materials in nature for improving human diet level based on quinoa dietary fiber, the structure, by Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron micrographs, physicochemical properties, such as viscosity, water-holding capacity and oil-holding capacity, and functional properties of hypoglycemic and antioxidant properties from Agriophyllum squarrosum seeds of three different regions were systematically analyzed in this paper. The results showed that all dietary fibers had typical infrared spectral characteristics of polysaccharides. Compared with quinoa soluble dietary fiber (SDF), Agriophyllum squarrosum SDF had a compact structure, higher mannose content (14.97~16.82 mg/mg) and DPPH free radical scavenging ability (63.18%~63.42%). Compared with insoluble dietary fiber from quinoa (IDF), Agriophyllum squarrosum IDF had more void space, and binding phenol content, water retention capacity, cholesterol adsorption capacity, in vitro hypoglycemic activity, DPPH radical scavenging activity, hydroxyl radical scavenging activity and reducing power were significantly higher (PAgriophyllum squarrosum dietary fiber had different morphological structure, physical properties and functional properties from quinoa dietary fiber, and would be a high-quality dietary fiber resource.