Structure–Function Modulation of Antarctic Krill Protein via Maillard Glycosylation with Mono- and Polysaccharides

Antarctic krill protein (AKP) was conjugated with three reducing monosaccharides (ribose, glucose, fructose) and five polysaccharides (xanthan gum, konjac glucomannan, inulin, κ-carrageenan, and pectin) via a controlled Maillard-type glycation process (pH 7.0, 90 °C, 24 h). We comparatively evaluated glycation reactivity (color change and degree of glycation), structural responses (particle size, FTIR, intrinsic fluorescence, surface hydrophobicity, and microstructure), and key techno-functional properties (solubility, water- and oil-holding capacities, and emulsifying performance). Monosaccharide-conjugated AKP exhibited stronger browning and higher apparent glycation activity, consistent with the higher reactivity of small-molecule sugars. In contrast, polysaccharide-conjugated AKP showed more pronounced improvements in dispersion-related and interfacial functions, reflecting enhanced steric stabilization and hydration after polysaccharide grafting. Notably, κ-carrageenan conjugation delivered the strongest overall functional enhancement (water-holding capacity ≈ 22.1 g/g; oil-holding capacity ≈ 10 g/g) and the most stable emulsions. These findings clarify how glycosylating-agent size and architecture steer AKP glycation outcomes, providing a practical basis for tailoring AKP ingredients for aqueous and emulsion-based foods.