Mechanism of ultrasound-modulated gluten-inulin interactions: Impact of inulin polymerization degree

This study investigated how ultrasound treatment (0-40 s) modulated the interaction between wheat gluten and inulin of different polymerization degrees (long-chain, FXL; short-chain, FS). The results revealed a distinct chain-length-dependent mechanism. Under optimal sonication (20-30 s), FXL promoted hydrophobic interactions, increased β-sheet content (up to 34.4%) and disulfide bonds (up to 34.9%), and facilitated the formation of a continuous, elastic protein network. This led to enhanced thermal stability (denaturation temperature up to 100.60 °C) and stable viscoelasticity (lower tan δ). In contrast, FS induced a loose, porous structure with inferior properties due to insufficient spatial confinement. Molecular docking further indicated that inulin bound preferentially to hydrophobic residues of gluten. This work elucidates the ultrasonic-mediated construction of gluten-inulin networks and provides a theoretical basis for tailoring high-fiber wheat products through controlled sonication.