Construction, characterization, antioxidant activity and effects on properties in vitro digestion of selenium nanoparticles decorated with Cyperus esculentus polysaccharides

In this study, in order to obtain selenium complex with high antioxidant activity and low release rate, selenium nanoparticles (SeNPs) were decorated by chemical reduction with Cyperus esculentus polysaccharides (CEP) as stabilizers (CEP-SeNPs). The characterization, construction mechanism, stability, and effects on properties in vitro digestion of CEP-SeNPs were investigated. CEP-SeNPs were orange-red in color and uniformly distributed in a spherical shape with an average diameter of 138.33 ± 0.57 nm, exhibiting good stability which could be stored at 4 °C. The selenium element in CEP-SeNPs was selenium in a zero-valent amorphous state. The O-H and C=O bonds in CEP were bound to selenium by an inductive effect to construct CEP-SeNPs for infrared analysis, and no new covalent bonds were formed in this process. CEP as stabilizer on selenium nanoparticles were physical combination. At the same time, the synergistic effects at antioxidant activity of polysaccharides and selenium was found which made CEP-SeNPs had a higher antioxidant activity than CEP. Above all, CEP-SeNPs showed better pH and enzyme stability in simulated digestion. The selenium release rate of CEP-SeNPs were only 18.52 % ± 0.17 % after intestinal digestion. The antioxidant activity of CEP-SeNPs were higher than that of CEP in the simulated digestion. It provides a theoretical basis for the development and utilization of rich selenium products.