Effect of Non-Covalent Interactions on Arabinoxylan-Protein Cross-Linking and Gluten-Free Batter Stability

Maize arabinoxylans (AX) and proteins (maize gluten meal, MGM) can partially replace gluten in gluten-free (GF) breads by forming polymer networks. This study investigated how non-covalent interactions (hydrophobic, electrostatic, or hydrogen (H) forces) influenced viscoelasticity, gas retention and enzymatic AX-protein cross-linking in simplified GF model batters using two maize AX extracts (commercial MAX; xylanase-extracted M-XEAX). Batter stability strongly depended on AX structure and formulation type. MGM-only controls were mainly governed by hydrophobic and electrostatic forces, while AX-based batters relied primarily on H-bonds and electrostatic interactions. Combining MGM and AX increased batter stiffness, dominated by electrostatic and H-interactions. Enzymatic coupling reinforced the AX-protein network when both H and electrostatic forces were present, whereas hydrophobic interactions partly hindered these associations. Changes in viscoelasticity (G') did not fully align with gas retention behaviour. In MGM-containing batters, gas retention was predominantly governed by H and electrostatic interactions. AX-based batters showed extract-dependent responses: electrostatic or H-interactions hindered gas stabilisation in M-XEAX, while their suppression supported gas-holding in enzyme-treated MAX batters. AX-MGM systems generally showed reduced gas expansion, indicating the contribution of multiple non-covalent interactions. Overall, batter stability strongly depended on AX structure, MGM addition, the balance of non-covalent interactions and the resulting network strength.