Abstract The changes in salt partition and the phase identification of non-diffusible calcium phosphate in bovine milk were studied at different temperature and pH upon heat treatment. As temperature and pH increased, the concentrations of serum Ca, inorganic phosphate (Pi) and citrate decreased, suggesting the formation of calcium phosphate materials. Besides, after heating at 100 °C the maximum buffering of milk occurred at pH 4.7 rather than pH 5.1, indicating that the newly formed calcium phosphate materials were chemically different from native micellar calcium phosphate (MCP). According to infrared spectrum, the calcium phosphate formed after high-heat treatment was likely to be alkaline salt, rather than acidic salt as native MCP was. Furthermore, high-heat treatment also resulted in significant increases in the average particle size and zeta potential of casein micelles, possibly due to crosslinks between caseins induced by decreases in electrostatic repulsion and steric effects of κ-caseins.

中文翻译：

---

温度和pH值对牛奶中盐平衡和磷酸钙的影响

摘要 研究了不同温度和pH条件下热处理后牛乳中盐分配的变化和非扩散性磷酸钙的相识别。随着温度和 pH 值的升高，血清 Ca、无机磷酸盐 (Pi) 和柠檬酸盐的浓度降低，表明形成了磷酸钙物质。此外，在 100 °C 加热后，牛奶的最大缓冲发生在 pH 4.7 而不是 pH 5.1，表明新形成的磷酸钙材料在化学上不同于天然胶束磷酸钙 (MCP)。根据红外光谱，高温处理后形成的磷酸钙很可能是碱性盐，而不是像天然MCP那样的酸性盐。此外，