Physicochemical Properties, Characterization, and Antioxidant Activity of Sodium Ferric Gluconate Complex

Sodium ferric gluconate complex (SFGC) was synthesized by a simple method using D-sodium gluconate (D-SG) and ferric chloride as raw materials, which was found to have chelated iron characteristics by measuring its physicochemical properties. The iron(III) complex was characterized by scanning electron microscopy (SEM), ultraviolet-visible spectrophotometry (UV-Vis), fourier transform infrared (FTIR), X-ray diffraction analysis (XRD) and differential scanning calorimetry (DSC). The results verified that the product was indeed the chelated iron complexes and its iron core was composed of iron oxyhydroxide namely beta-FeOOH mineral polymorph. Moreover, antioxidant activity of SFGC was evaluated by the half maximal inhibitory concentration (IC50) against hydroxyl free radical, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical, nitrite and lipid peroxidation, and their values were 3.65, 8.09, 3.01, 1.90 mg/mL, respectively. These results demonstrate that SFGC is expected to become a good iron supplement with a variety of biological activity or food additive strengthening iron.