Novel iron-chelating peptide from egg yolk: Preparation, characterization, and iron transportation

In this work, an egg yolk protein hydrolysate (EYPH) with a high iron-chelating ability (87.32%) was prepared. The fractionation using 60% (v/v) ethanol concentration (E3 fraction) led to the efficiently accumulating the iron-chelating peptides in EYPH. The characterization results showed that iron mainly chelated with carboxyl, amino and phosphate groups of peptides. From E3 fraction, six iron-chelating peptides with MW ranging from 1372.36 to 2937.04 Da were identified and a hypothesized molecular model of DDSSSpSpSpSpSpSVLSK-Fe was simulated. In vitro stability determination showed that E3-Fe chelate owned a good heat, alkalinity and digestion tolerance, but a relatively bad acid tolerance. Finally, iron transport analysis showed that iron in the E3-Fe would be absorbed in caco-2 cell membrane more effectively than that of iron salts, indicating that it was possible to apply the E3-Fe complex as iron supplements.

Automated summary

In this study, a high iron-chelating ability (87.32%) egg yolk protein hydrolysate (EYPH) was prepared. Fractionation using 60% (v/v) ethanol concentration (E3 fraction) efficiently accumulated the iron-chelating peptides in EYPH. Characterization results revealed that iron mainly chelated with carboxyl, amino, and phosphate groups of peptides. Six iron-chelating peptides ranging from 1372.36 to 2937.04 Da were identified from the E3 fraction, and a hypothesized molecular model of DDSSSpSpSpSpSpSVLSK-Fe was simulated. In vitro stability determination showed that the E3-Fe chelate had good heat, alkalinity, and digestion tolerance, but relatively poor acid tolerance. Iron transport analysis demonstrated that iron in the E3-Fe complex would be more effectively absorbed in caco-2 cell membrane compared to iron salts, suggesting the potential application of the E3-Fe complex as iron supplements.