Mitigating the cold denaturation of gluten protein during frozen storage is crucial for the quality improvement of frozen cereal products. Our previous study observed that starch derivatives, especially short-clustered maltodextrin (SCMD), could significantly improve frozen dough quality, alleviating the deterioration of gluten-network structure. To further reveal the cryoprotection mechanism of SCMD on gluten protein during frozen storage, the modulatory roles of SCMD in the hydration capacity and conformation behavior of gluten protein were explored, in comparison with DE2 maltodextrin (MD) and pregelatinized starch (PGS). Results demonstrated that SCMD significantly facilitated the reservation of bound water and decreased the surface hydrophobicity of gluten protein after 8 weeks of frozen storage. Remarkable effects of SCMD on stabilizing the secondary structure and microenvironment of aromatic amino acids of gluten protein were observed. Further mechanistic investigation showed that when the temperature dropped from 300 to 250 K, the short-clustered structure could stabilize the α-helixes more evidently than linear structures through hydrogen bonds with water and steric hindrance effect, rather than directly with protein. Our findings will provide novel insights into the cold denaturation of gluten protein and useful guidance in selecting the optimum structure to suppress this denaturation, improving the quality of frozen cereal products.

中文翻译：

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减轻淀粉衍生物对面筋蛋白冷变性的影响：来自水合能力和构象行为的见解


减轻冷冻储存过程中面筋蛋白的冷变性对于提高冷冻谷物产品的质量至关重要。我们之前的研究观察到淀粉衍生物，尤其是短簇麦芽糖糊精 （SCMD），可以显着提高冷冻面团的质量，缓解面筋网络结构的恶化。为进一步揭示 SCMD 在冷冻贮藏过程中对面筋蛋白的冷冻保护机制，与 DE2 麦芽糊精 （MD） 和预胶化淀粉 （PGS） 相比，探讨了 SCMD 在面筋蛋白水合能力和构象行为中的调节作用。结果表明，冷冻储存 8 周后，SCMD 显着促进了结合水的保留并降低了面筋蛋白的表面疏水性。观察到 SCMD 对稳定面筋蛋白芳香族氨基酸的二级结构和微环境的显著作用。进一步的机理研究表明，当温度从 300 K 下降到 250 K 时，短簇状结构比线性结构更能通过与水的氢键和空间位阻效应稳定 α 螺旋，而不是直接与蛋白质。我们的研究结果将为面筋蛋白的冷变性提供新的见解，并为选择最佳结构来抑制这种变性、提高冷冻谷物产品的质量提供有用的指导。