Conjugates of glycosylated antarctic krill proteins and curcumin: Maintaining the storage quality of salmon fillets coupling with photodynamic inactivation

Abstract

Antarctic krill proteins (AKP) were successfully glycosylated by inulin driven by ultrasound (300 W, 20 min) and pH shift (11.0) to prepare the conjugates of glycosylated AKP and curcumin. The preservation effects of the conjugates-mediated photodynamic inactivation (PDI) on the storage quality of salmon fillets were investigated. Results showed that the glycosylated AKP (AKP-pH11-U20) exhibited a significantly increased solubility, and a relatively small and loose morphology characterized by SEM, an unfolded and disorganized structure by FTIR and intrinsic fluorescence analysis, and a decreased surface hydrophobicity by bromophenol blue staining, and all these changes contributed to its reduced surface tension. On this basis, the glycosylated AKP efficiently loaded curcumin (323.4 μg/mg) to form the conjugates, and the conjugates-mediated PDI greatly inhibited 99.8% bacterial cells and the migration of water, retarded the change of color and pH, suppressed the lipid oxidation and degradation during 4 °C storage for 7 days, compared to the conventional curcumin-mediated PDI. This study expands the application of new marine protein resources in preserving the quality of aquatic products.