Green synthesis of wampee polysaccharide-Fe (II): Structural characterization, stability, bioactivity and digestive properties

For green synthesis of polysaccharide-iron (II) complexes, crude polysaccharide extracted from wampee (CWP) was used as carrier with quercetin being reducing agents to prepare CQ-Fe (II). Results indicated that the proportion of Fe (II) in CQ-Fe (II) was 93 % and it had a relatively higher molecular weight (1.43 × 10 6 Da) compared with CWP. They had the same monosaccharide composition but with slightly different molar ratios. Structural characterization indicated the formation of Fe-O bonds, no triple helix structure and changed micromorphology, with an average particle size of 61.27 nm. Moreover, CQ-Fe (II) maintained good stability under various temperature, pH and ionic strength conditions. The introduction of Fe (II) significantly improved antioxidant and hypoglycemic activities of CQ-Fe (II). During in vitro digestion, it had a higher release rate of iron compared with FeSO 4 , which had broad prospect in iron supplements and functional foods industry. • CQ-Fe (Ⅱ) was successfully green-synthesized using quercetin as reducing agent. • CQ-Fe (Ⅱ) had excellent stability and improved antioxidant, hypoglycemic activity. • CQ-Fe (II) showed better in vitro digestion properties than FeSO 4 .