Abstract Besides deionised water, tap or softened water could be used as diafiltration media for separation and purification of the casein fraction from milk by means of membrane technology. The effect of compositional differences on key properties of casein micelles was investigated with these media and simulated milk serum as reference at laboratory scale under conditions mimicking typical industrially applied diafiltration processes. Evaluation of zeta-potential, particle size distribution, voluminosity as well as casein and calcium composition revealed marked differences of micellar attributes at temperatures of 10 and 50 °C depending mainly on the medium hardness. While tap water induced a slight micellar contraction, dehardened water types differently fostered a swelling that was followed by partial disintegration over contact time especially at 50 °C. Results demonstrate that water composition impacts micellar properties in typical DF conditions, which can, in consequence, be crucial for processing efficiency and product functionality of obtained casein products.

中文翻译：

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不同水相对酪蛋白胶束的影响：水硬度和渗滤条件变化下的物理化学变化动力学

摘要 除去离子水外，自来水或软化水也可作为渗滤介质，通过膜技术从牛奶中分离纯化酪蛋白。在模拟典型工业应用渗滤过程的条件下，使用这些培养基和模拟乳清作为参考，在实验室规模下研究了成分差异对酪蛋白胶束关键特性的影响。zeta 电位、粒度分布、体积以及酪蛋白和钙成分的评估表明，胶束属性在 10 和 50 °C 的温度下存在显着差异，主要取决于介质硬度。虽然自来水引起轻微的胶束收缩，不同类型的脱硬水促进了膨胀，随后在接触时间内部分崩解，尤其是在 50 °C 时。结果表明，水组成会影响典型 DF 条件下的胶束特性，因此，这对获得的酪蛋白产品的加工效率和产品功能至关重要。