Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Food Res Int. 2021 Feb;140:109856. doi: 10.1016/j.foodres.2020.109856. Epub 2020 Nov 3.
Adding fibers to hydrogels is a modern strategy for producing tough hydrogels. Nanofibers usually perform well in hydrogels due to their unique properties. The purpose of this study was to investigate the effects of whey protein amyloid fibril (WPF) on the properties ofheat-set whey proteinisolate (WPI)gels with fine-stranded or particulate microstructure (at pH 7). The results show that by adding WPF, a homogenous and dense network was observed in fine-stranded gel, while the formation of a coarse and amorphous structure with microphase separation intensified in particulate gel. By adding 1% WPF, the elastic modulus of gels increased about 10.6 and 3.6 times in the case of fine-stranded and particulate gels, respectively. In fine-stranded gels, adding WPF to the gel led to a decrease in the T value (from 66.33 to 59.36 °C) and a decrease in tan δ (from 0.2328 to 0.0837), indicating an increase in gel strength because of WPF. In contrast, adding WPF to particulate gels did not cause significant changes in the T and tan δ. There was a decrease in the water holding property of particulate gels when WPF was added, whereas it did not change significantly in fine-stranded gels. These findings imply that the efficiency of WPF in WPI gels depends not only on the WPF concentration but also on the type of the WPI gel. In sum, WPF enhances order in the structural network of fine-stranded gels, while accelerating the formation of inhomogeneous random aggregates in particulate gels. Creating fiber-hydrogels with different microstructures and rheological properties can be possible by controlling WPI aggregation (as in amyloid fibril, fine-strand or particulate aggregates).
向水凝胶中添加纤维是一种生产坚韧水凝胶的现代策略。由于纳米纤维具有独特的性质，因此通常在水凝胶中表现良好。本研究的目的是研究乳清蛋白淀粉样纤维（WPF）对具有细带状或颗粒状微观结构的热定乳清蛋白分离物（WPI）凝胶（pH7）性质的影响。结果表明，通过添加 WPF，在细带状凝胶中观察到均匀且致密的网络，而在颗粒状凝胶中形成了具有微相分离的粗糙无定形结构。在细带状凝胶中，添加 1%的 WPF 分别使凝胶的弹性模量增加了约 10.6 倍和 3.6 倍。在细带状凝胶中，向凝胶中添加 WPF 会导致 T 值（从 66.33°C 降低至 59.36°C）和 tanδ（从 0.2328 降低至 0.0837）降低，表明由于 WPF 的存在凝胶强度增加。相比之下，向颗粒状凝胶中添加 WPF 不会导致 T 和 tanδ发生明显变化。当添加 WPF 时，颗粒状凝胶的持水性能下降，而在细带状凝胶中则没有明显变化。这些发现表明，WPF 在 WPI 凝胶中的效率不仅取决于 WPF 的浓度，还取决于 WPI 凝胶的类型。总之，WPF 增强了细带状凝胶结构网络的有序性，同时加速了颗粒状凝胶中不均匀随机聚集体的形成。通过控制 WPI 聚集（如淀粉样纤维、细带状或颗粒状聚集体），可以制造具有不同微观结构和流变性能的纤维水凝胶。
