The aim was to optimise the yield of co‐precipitation of whey protein isolate (WPI) and pea protein isolate (PPI) and compare co‐precipitates and protein blends with respect to solubility. The yield of co‐precipitates was tested with different protein ratios of WPI and PPI in combination with different temperatures and acid precipitation (pH 4.6). The highest precipitation yield was obtained at protein ratios WPI < PPI, high temperature and alkaline protein solvation. The solubility was measured by an instability index and absorption spectroscopy of re‐suspended precipitated proteins at pH 3, 7 and 11.5. Co‐precipitates had significantly lower solubility than protein blends. Protein ratios WPI > PPI, low precipitation temperature and high pH showed the highest solubility. Differences in protein composition between co‐precipitates and protein blends were observed with SDS‐PAGE and matrix‐assisted laser desorption ionisation time‐of‐flight, and indicated different protein–protein interaction in samples, which needs further investigations.

中文翻译：

---

乳清和豌豆蛋白共沉淀-相互作用的指示

目的是优化乳清蛋白分离物（WPI）和豌豆蛋白分离物（PPI）的共沉淀产量，并比较共沉淀物和蛋白混合物的溶解度。使用不同的WPI和PPI蛋白质比例以及不同的温度和酸沉淀（pH 4.6）来测试共沉淀物的产量。在蛋白质比WPI <PPI，高温和碱性蛋白质溶剂化条件下，可获得最高的沉淀产量。通过不稳定性指数和重悬沉淀的蛋白质在pH 3、7和11.5的吸收光谱测量溶解度。共沉淀物的溶解度明显低于蛋白质混合物。蛋白质比例WPI> PPI，低沉淀温度和高pH值显示出最高的溶解度。