Preparation, characterization, stability and bioactivity of fermented Tremella polysaccharide-Fe3+ complex

The second-generation of iron supplements is known for its instability, thus leading to the emergence of polysaccharide iron complexes as a novel third-generation iron supplement, which has garnered significant scholarly attention. Yet, there is a limited body of academic literature on the stability and biological activity of polysaccharide iron complexes. The objective of this study is to investigate the stability, release of Fe3+, and biological activity of fermented Tremella polysaccharide after complexation with Fe3+ in order to address the research gaps in this field. The combination of Fe3+ and polysaccharide was confirmed successful by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and circular dichroism spectroscopy. The release rate of the fermented Tremella polysaccharide-Fe3+ complex in simulated gastric fluid for 0.5 h was found to be 76% ± 2%, indicating a favorable release profile. Additionally, the complex exhibited excellent viscosity stability, while the introduction of Fe3+ into Tremella polysaccharide resulted in improved thermal and solution stability. Moreover, the complex exhibits excellent antioxidant and hypoglycemic activity in vitro. The results demonstrate that the complex possesses exceptional stability and dual efficacy in terms of iron replenishment and nutrition, thus positioning it as a potential key player among novel iron supplements.