Excellent iron-chelating capacity of Yesso scallop (Patinopecten yessoensis) skirt hydrolysate fermented by Bacillus subtilis M17-b7

Peptide ferrous chelate is a new type of biological iron, which has the advantages of high absorption rate, safety and no digestive tract irritation. In this study, microbial fermentation was used for the first time to prepare iron-chelating peptides. Forty-eight strains were applied to ferment scallop skirts. A dominating strain was eliminated by using the iron binding capacity of the scallop skirt hydrolysate as the screening index. The scallop skirt hydrolysate fermented by Bacillus subtilis M17-b7 showed excellent iron-chelating capacity (96.20% ± 0.03%). Meanwhile, the structure, morphology and bioactivity of fermented scallop skirt hydrolysate (FSH) and fermented scallop skirt hydrolysate-iron (FSH–Fe) were measured. Based on the amino acid composition and spectral analysis, it was confirmed that the significant amino acids contains carboxyl, carbonyl, and amino groups. The result of scanning electron microscope indicated that the surface of FSH became porous and the particles were bigger after chelating with ferrous. Moreover, the peptide-ferrous chelate was more stable in salt solutions and simulated gastric juice compared with ferrous sulfate. It is also noteworthy that the preparation of ferrous chelate peptides by fermentation is cost-effective compared with enzymatic hydrolysis. Therefore, this study provides theoretical support for the use of fermentation as a promising tool to produce peptide-ferrous chelate.