Preparation process optimization, structural characterization and in vitro digestion stability analysis of Antarctic krill (Euphausia superba) peptides-zinc chelate

In the study, a novel kind of peptides-zinc (AKP-Zn) chelate was obtained using the Antarctic krill (Euphausia superba) peptides (AKP) as raw material, the reaction was carried out with the mass ratio of the AKP to ZnSO4 center dot 7H(2)O of 1:2 at pH 6.0 and 60 degrees C for 10 min. The structure and composition of the AKP, including particle size, Zeta potential, molecular weight distribution, amino acid composition, microstructure and surface elemental composition, changed significantly after chelating with zinc. The result of Fourier transform infrared spectroscopy indicated that zinc could be chelated by carboxyl oxygen and amino nitrogen atoms of the AKP. Furthermore, compared with zinc sulfate and zinc gluconate, the AKP-Zn chelate was more stable at various pH conditions and the simulated gastrointestinal digestion experiment. These findings would provide a scientific basis for developing new zinc supplements and the high-value utilization of Antarctic krill protein resource.

Automated summary

In this study, a novel peptides-zinc chelate (AKP-Zn) was obtained by reacting Antarctic krill peptides (AKP) with zinc sulfate. The structure and composition of AKP changed significantly after chelating with zinc. AKP-Zn chelate showed higher stability than zinc sulfate and zinc gluconate in various pH conditions and simulated gastrointestinal digestion experiments.