Miao, J., et al. Isolation and identification of iron-chelating peptides from casein hydrolysates. Food & Function. 1-32. 3/4/2019.

Iron deficiency is a common nutritional disorder in the world. Peptides derived from protein hydrolysates have recently attracted interest as novel iron chelators due to its superiority in terms of increasing solubility, bioavailability, absorption and stability. The aim of this study was to isolate and identify iron-chelating peptides from casein hydrolysates. Casein was hydrolyzed (trypsin, 3 h), and subsequently isolated using ultrafiltration and RP-HPLC. Four iron-chelating peptides, named casein hydrolysate peptides (CHP-1), CHP-2, CHP-3 and CHP-4, were identified by LC-MS/MS, and the amino acid sequences were Glu-Asp-Val-Pro-Ser-Glu-Arg (EDVPSER), His-Lys-Glu-Met-Pro-Phe-Pro-Lys (HKEMPFPK), Asn-Met-Ala-Ile-Asn-Pro-Ser-Lys (NMAINPSK) and Ala-Val-Pro-Tyr-Pro-Gln-Arg(AVPYPQR), with molecular weights of 830.377 Da, 1012.5164 Da, 873.4378 Da and 829.4446 Da, respectively. The artificially synthesized peptides of HP-1, CHP-2, CHP-3 and CHP-4 were verified and the iron-chelating rates were 11.14%, 8.02%, 7.57% and 59.76%, respectively. These results suggested that HP-1, CHP-2, CHP-3 and CHP-4 might serve as potential iron supplement and be used as food additives and functional foods.