Structural Reconfiguration of Antarctic Krill Protein by Ultrasound-Assisted Inulin Glycosylation for Improved Resveratrol Incorporation and Emulsion Stability

Abstract Antarctic krill protein (AKP) is a high-value marine protein limited by aggregation, low solubility, and poor compatibility with hydrophobic bioactives. Here, we applied ultrasound-assisted inulin glycosylation to prepare AKP–inulin conjugates and AKP–inulin–resveratrol ternary complexes, systematically examining their structure–function relationships. Ultrasound enhanced glycosylation, reaching the highest grafting degree at 480 W, and improved colloidal stability, as indicated by reduced particle size and increased absolute zeta potential. Structural analyses revealed α-helix reduction, increased β-sheet and disordered structures, molecular unfolding, and enhanced cross-linking. The 480 W ternary complex exhibited superior emulsifying activity, high interfacial protein adsorption, improved 10-day storage stability, and enhanced antioxidant capacity, with DPPH scavenging reaching 63.41%. These results demonstrate that ultrasound-assisted glycosylation reconfigures AKP into a resveratrol-containing, interfacially active matrix with improved colloidal and emulsion stability, providing mechanistic insight into protein–polysaccharide interactions and supporting the development of AKP-based ternary complexes for functional food applications.