Chair of Food and Bioprocess Engineering, Technical University of Munich, Weihenstephaner Berg 1, 85354 Freising, Germany.
Laboratory of Food Process Engineering, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
Molecules. 2020 Sep 25;25(19):4417. doi: 10.3390/molecules25194417.
This study aims at investigating the effect of ethanol (EtOH) on the textural properties of whey protein and egg white protein hydrogels. The hydrogels were produced by thermally induced gel formation of aqueous protein solutions. The water contained in the gel network was subsequently exchanged by EtOH to assess structural changes upon exposure of hydrogels to ethanolic aqueous phases. The textural properties of the hydrogel and alcogel samples were analyzed by uniaxial compression tests. For both protein sources, the hardness increased exponentially when pH and EtOH concentration were increased. This increase correlated with a shrinkage of the gel samples. The gel texture was found to be elastic at low EtOH concentrations and became stiff and hard at higher EtOH concentrations. It was found that the solvent exchange influences the ion concentration within the gels and, therefore, the interactions between molecules in the gel structure. Non-covalent bonds were identified as substantially responsible for the gel structure.
本研究旨在探讨乙醇（EtOH）对乳清蛋白和蛋清蛋白水凝胶的结构特性的影响。水凝胶是通过水相蛋白质溶液的热诱导凝胶形成而制备的。凝胶网络中的水分随后被 EtOH 取代，以评估水凝胶暴露于含乙醇的水相时的结构变化。通过单轴压缩试验分析水凝胶和醇凝胶样品的结构特性。对于这两种蛋白质来源，当 pH 和 EtOH 浓度增加时，硬度呈指数增加。这种增加与凝胶样品的收缩相关。在低 EtOH 浓度下，凝胶质地表现出弹性，而在较高 EtOH 浓度下变得坚硬。研究发现，溶剂交换会影响凝胶内的离子浓度，从而影响凝胶结构中分子之间的相互作用。非共价键被确定为凝胶结构的主要原因。
