Structure characterization and antioxidant activity of abalone visceral peptides-selenium in vitro

Peptide-selenium chelate is widely regarded as one of the best selenium supplements for relieving selenium deficiency. In this study, abalone visceral peptides (AVP) was used to prepare a new type of peptides-selenium chelate to develop an organic selenium supplement with antioxidant activity. AVP prepared by alcalase exhibited the highest selenium-chelating ability. UV-visible spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy and other structural analysis showed that selenium was mainly bound to the functional groups of -NH, -OH, -CH, CC, CO, and CN bonds on AVP. The formation of AVP-selenium chelate enhanced thermal stability and generated a new crystal structure. The ABTS^•+ and ^•OH scavenging activities of AVP-selenium chelate were increased after in vitro digestion than that of AVP. Conclusively, this study analyzed the chelating mechanism of AVP and selenium from a structural perspective, which would provide a theoretical basis for the development of new selenium supplements.