Mitigating the\nEffects of Starch Derivatives on Cold\nDenaturation of Gluten Protein: Insights from Hydration Capacity and\nConformation Behavior

Mitigating the cold denaturation of gluten protein during\nfrozen\nstorage is crucial for the quality improvement of frozen cereal products.\nOur previous study observed that starch derivatives, especially short-clustered\nmaltodextrin (SCMD), could significantly improve frozen dough quality,\nalleviating the deterioration of gluten-network structure. To further\nreveal the cryoprotection mechanism of SCMD on gluten protein during\nfrozen storage, the modulatory roles of SCMD in the hydration capacity\nand conformation behavior of gluten protein were explored, in comparison\nwith DE2 maltodextrin (MD) and pregelatinized starch (PGS). Results\ndemonstrated that SCMD significantly facilitated the reservation of\nbound water and decreased the surface hydrophobicity of gluten protein\nafter 8 weeks of frozen storage. Remarkable effects of SCMD on stabilizing\nthe secondary structure and microenvironment of aromatic amino acids\nof gluten protein were observed. Further mechanistic investigation\nshowed that when the temperature dropped from 300 to 250 K, the short-clustered\nstructure could stabilize the α-helixes more evidently than\nlinear structures through hydrogen bonds with water and steric hindrance\neffect, rather than directly with protein. Our findings will provide\nnovel insights into the cold denaturation of gluten protein and useful\nguidance in selecting the optimum structure to suppress this denaturation,\nimproving the quality of frozen cereal products.