酪蛋白-载铁透明质酸复合物的结构及理化性质OA

Iron deficiency anemia is an important nutritional deficiency disease worldwide.Developing efficient and safe iron fortified food is an effective strategy to improve iron nutrition.However,iron ions are prone to adverse interactions in food systems,resulting in low bioaccessibility.A composite delivery system based on casein(CAS)and iron loaded hyaluronic acid(HA-Fe)was constructed to improve the stability and bioavailability of iron ions.Compositions with m(CAS)∶m(HA-Fe)ratios of 10∶1 and 5∶1 were prepared.The structural properties of CAS were systematically characterized by nanoparticle size analyzer,zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),ultraviolet absorption spectroscopy and intrinsic fluorescence spectroscopy,and the release behavior and bioaccessibility of iron ions were evaluated by simulating gastrointestinal digestion model in vitro.Results showed that the stability of the system significantly improved after CAS-HA-Fe complexation,with increased absolute Zeta potential and more uniform particle size distribution.FT-IR revealed changes in secondary structure.Ultraviolet absorption spectroscopy and fluorescence spectra showed that the tertiary structure of protein changed and the tryptophan microenvironment tended to be hydrophobic.In vitro digestion experiments revealed that the bioavailability of iron ions reached its peak at 18.9%when the molar ratio of m(CAS)∶m(HA-Fe)was 5∶1.Casein iron loaded hyaluronic acid complex has good structural stability and iron protection ability,and can be used as a potential high-efficiency carrier for iron nutrition enhancement in functional foods.