Oyster Peptide-Ferrous Chelate Preparation Optimization Structural Characteristics and Enhanced Bioavailability

Iron deficiency anemia remains a global nutritional challenge due to the low bioavailability and side effects of conventional inorganic iron supplements. A novel organic iron supplement, oyster peptide ferrous chelate (OP-Fe), was prepared using oyster peptides as ligands. Its preparation process was optimized via single-factor experiments and statistical methods with the optimal conditions identified as 1% peptide concentration, 35 °C chelation temperature, 3.91:1 peptide-to-iron ratio, 1.49% ascorbic acid concentration and pH 6.05. Under these conditions, the chelate's iron content reached 15.44 ± 0.18 g/kg. Multi-dimensional characterization confirmed that Fe²⁺ formed stable complexes with oyster peptides through carboxyl, amino, and imidazole groups. In vitro Caco-2 cell experiments showed OP-Fe achieved a maximum iron absorption rate of 76.07%, significantly higher than ferrous sulfate (52.39%). In vivo pharmacokinetic studies in mice demonstrated higher iron accumulation in serum and small intestine for OP-Fe. Key iron transport-related genes (PEPT1, TFR1, DMT1) were upregulated, contributing to enhanced absorption. OP-Fe exhibits favorable structural stability and bioavailability, holding potential as an efficient iron supplement.