Abstract Phycocyanin, a natural blue colorant from Spirulina, can form aggregate and precipitate in acidified beverages. In order to solve the aggregation problem of phycocyanin at low pH, we used whey protein to improve the stability of phycocyanin in acidified conditions. Our results showed that whey protein is much more effective compared to pea and egg white proteins in preventing the aggregation of phycocyanin at pH 3.0, in which a minimum 10% of whey protein solution is required to completely prevent the aggregation. In addition, undenatured whey protein is more effective compared to denatured and hydrolyzed forms. We found that α-lactalbumin, β-lactoglobulin, BSA, immunoglobulins, and glycomacropeptides may all participate in the encapsulation of the phycocyanin molecule. The Fourier transform infrared spectroscopy, native-polyacrylamide gel electrophoresis, and zeta-sizer results also proved that the complete whey protein provides better protection for phycocyanin compared to BSA or whey protein without the glycomacropeptides. The study provides a natural way to stabilize phycocyanin at acidified conditions, making it possible to use phycocyanin as a blue colorant in acidified beverages.

中文翻译：

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使用乳清蛋白-藻蓝蛋白相互作用改善酸化条件下藻蓝蛋白的胶体稳定性

摘要 藻蓝蛋白是一种来自螺旋藻的天然蓝色着色剂，可在酸化饮料中形成聚集体和沉淀。为了解决藻蓝蛋白在低pH下的聚集问题，我们使用乳清蛋白来提高藻蓝蛋白在酸化条件下的稳定性。我们的结果表明，与豌豆和蛋清蛋白相比，乳清蛋白在阻止藻蓝蛋白聚集方面更有效，pH 值为 3.0，其中至少需要 10% 的乳清蛋白溶液才能完全阻止聚集。此外，与变性和水解形式相比，未变性的乳清蛋白更有效。我们发现α-乳清蛋白、β-乳球蛋白、BSA、免疫球蛋白和糖巨肽都可能参与藻蓝蛋白分子的封装。傅里叶变换红外光谱，天然聚丙烯酰胺凝胶电泳和 zeta-sizer 结果也证明，与不含糖巨肽的 BSA 或乳清蛋白相比，完整的乳清蛋白可为藻蓝蛋白提供更好的保护。该研究提供了一种在酸化条件下稳定藻蓝蛋白的自然方法，使得在酸化饮料中使用藻蓝蛋白作为蓝色着色剂成为可能。