Abstract Gelation of whey protein fractal aggregates was induced by simultaneously adding salt (CaCl2 or NaCl) and acid (HCl). Further, simultaneous addition of both specifically binding (Ca2+) and non-binding (Na+) cations was studied at a fixed protein charge density. The effect of adding mixtures of ions on pH, gelation kinetics, elastic modulus and gel microstructure was investigated. For all studied systems the time of gelation (tg) had an Arrhenius dependence on temperature, characterised by an activation energy (Ea). The value of Ea depended on the type and concentration of added ions. The elastic modulus of gels was found to be independent of the ion composition, reaching 0.2–0.3 kPa at a protein concentration of 40 g L−1 and 1 kPa at 60 g L−1. At conditions of strong electrostatic repulsion between aggregates, addition of NaCl reduced tg. However, when the repulsions were weak, further addition of NaCl increased tg.

中文翻译：

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由添加的 HCl、CaCl2 和 NaCl 之间的相互作用引起的乳清蛋白分形聚集体的凝胶化

摘要 通过同时加入盐（CaCl2 或 NaCl）和酸（HCl）诱导乳清蛋白分形聚集体的凝胶化。此外，在固定的蛋白质电荷密度下研究了同时添加特异性结合 (Ca2+) 和非结合 (Na+) 阳离子。研究了添加离子混合物对 pH、凝胶化动力学、弹性模量和凝胶微观结构的影响。对于所有研究的系统，凝胶化时间 (tg) 与温度具有 Arrhenius 相关性，以活化能 (Ea) 为特征。Ea 的值取决于添加离子的类型和浓度。发现凝胶的弹性模量与离子组成无关，在蛋白质浓度为 40 g L-1 时达到 0.2–0.3 kPa，在 60 g L-1 时达到 1 kPa。在聚集体之间存在强静电排斥的条件下，添加 NaCl 降低了 tg。