Polysaccharides may form stable complexes with caseins to prevent precipitation near the isoelectric point of pH 4.6. In this study, dispersions of 1% w/v micellar caseins and propylene glycol alginate (PGA) were treated with a pH-cycle treatment from neutral to pH 11.30, to dissociate casein micelles, and then to pH 4.5 to re-associate caseins to form complexes with PGA. An increase in PGA concentration overall resulted in the reduced dispersion turbidity. The dispersion with equal masses of casein and PGA following the pH-cycle treatment had the lowest turbidity (260 NTU) and was absent of both precipitation and gelation during 30-day storage at 21 °C, contrasting with unstable and turbid (>4000 NTU) dispersions directly acidified to pH 4.5. The dispersion turbidity was determined by both the size and mass density of particles, and both covalent and non-covalent (mainly electrostatic and hydrophobic) interactions contributed to the complex formation and dispersion stability at pH 4.5.

中文翻译：

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在pH循环处理后，通过藻酸丙二醇酯使pH值稳定的酪蛋白胶束分散液达到4.5。

多糖可以与酪蛋白形成稳定的复合物，以防止在pH 4.6的等电点附近沉淀。在这项研究中，对1％w / v胶束酪蛋白和海藻酸丙二醇酯（PGA）的分散液进行了pH循环处理（从中性至pH 11.30），以分离酪蛋白胶束，然后至pH 4.5以使酪蛋白重新缔合。与PGA形成配合物。总的来说，PGA浓度的增加导致分散浊度降低。pH循环处理后，具有相同质量的酪蛋白和PGA的分散体的浊度最低（260 NTU），并且在21°C的30天存储过程中既没有沉淀也没有凝胶化，相比之下不稳定和浑浊（> 4000 NTU） ）分散体直接酸化至pH 4.5。分散浊度由颗粒的大小和质量密度决定，