Selenium nanoparticles (SeNPs) were prepared by using gum arabic (GA) as the stabilizer in a facile
synthetic approach. The size, morphology, stability and antioxidant activity in vitro of the gum arabicselenium nanocomposites (GA-SeNPs) were characterized by transmission electron microscopy (TEM),
dynamic light scattering (DLS), Fourier-transforminfrared spectroscopy (FTIR), atomic forcemicroscopy
(AFM) and ultraviolet–visible spectrophotometry (UV–vis). SeNPs (particle size of ∼34.9nm) can be stabilized in gum arabic aqueous solutions for approximately 30 days. FTIR results show that SeNPs were
combined to the hydroxyl groups of GA. In the present work, the alkali-hydrolyzed GA (AHGA) was
also prepared and its efficiency in stabilizing SeNPs was compared with GA. It was concluded that the
branched structure of GA was a significantfactor for the functionality. The hydroxyl radical scavenging
ability andDPPHscavenging abilityofGA-SeNPswerehigher thanthoseofAHGA-SeNPs andcouldreach
85.3±2.6%, 85.3±1.9% at a concentration of 4mg/ml, respectively.