Abstract The effects of varying the initial pH from 5 to 9 on Maillard reaction-induced whey protein gel formation and structural and rheological properties were determined. The molecular mass of whey protein and reducing sugar conjugates increased according to SDS-PAGE determination. Amino and surface sulphydryl groups were decreased, contributing to gel network formation. The amide I and II bands at 1640 cm−1 and 1550 cm−1, respectively, were decreased and the amide III peak at 1200–1300 cm−1 increased, indicating the amino groups were participating in complex cascade reactions and the Maillard reaction during gel formation. Fluorescence measurements revealed that exposed tryptophan residues could increase the hydrophilic properties of the glycosylated protein. Gels formed from whey protein + glucose and from whey protein + xylose at an initial pH of 5 and 7, respectively, had a higher elastic modulus (G′), which was related to increased β-sheet and random coil formation after the Maillard reaction.

中文翻译：

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可变初始 pH 值对乳清蛋白结构和流变学特性的影响以及通过美拉德反应胶凝的单糖

摘要 确定了从 5 到 9 的初始 pH 值对美拉德反应诱导的乳清蛋白凝胶形成以及结构和流变特性的影响。根据 SDS-PAGE 测定，乳清蛋白和还原糖缀合物的分子量增加。氨基和表面巯基减少，有助于凝胶网络的形成。在 1640 cm-1 和 1550 cm-1 处的酰胺 I 和 II 谱带分别减少，而在 1200-1300 cm-1 处的酰胺 III 峰增加，表明氨基参与了复杂的级联反应和美拉德反应。凝胶形成。荧光测量表明，暴露的色氨酸残基可以增加糖基化蛋白质的亲水性。