College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
Food Chem. 2024 Sep 30;453:139672. doi: 10.1016/j.foodchem.2024.139672. Epub 2024 May 17.
The structure and functional properties of protein fibrils are closely related to environmental factors in fibrillation. Herein, soy protein isolate fibrils (SPIFs, 22 mg/mL) were prepared under acid-heating conditions in the presence of 100 mM metal ions (K, Na, Ca, Mg, and Fe). Except for Fe, fibrillation and subsequent larger fibril aggregates were promoted, ultimately leading to gel formation. Compared with K or Na, the addition of Ca or Mg resulted in more organized SPIF structures with increased β-sheet contents and higher ThT fluorescence intensities. Furthermore, both of them resulted in longer fibrils with an average contour length of 700-800 nm, which significantly enhanced the storage modulus. However, the presence of Fe accelerated protein hydrolysis and inhibited SPIF formation, resulting in samples consistently exhibited liquid behavior. These findings provide a foundation for understanding the influence of metal ions on regulating the fibrillation and gelling properties of SPIFs.
蛋白质纤维的结构和功能特性与其在纤维化过程中的环境因素密切相关。在此，在存在 100mM 金属离子（K、Na、Ca、Mg 和 Fe）的情况下，通过酸加热条件制备大豆分离蛋白纤维（SPIF，22mg/mL）。除了 Fe 之外，纤维形成和随后更大的纤维聚集物都得到了促进，最终导致凝胶形成。与 K 或 Na 相比，添加 Ca 或 Mg 导致 SPIF 结构更具组织性，β-折叠含量增加，ThT 荧光强度更高。此外，它们都导致更长的纤维，平均轮廓长度为 700-800nm，这显著提高了储能模量。然而，Fe 的存在加速了蛋白质水解并抑制了 SPIF 的形成，导致样品始终表现出液体行为。这些发现为理解金属离子对调节 SPIF 纤维化和胶凝特性的影响提供了基础。
