The dairy industry has long known that highly concentrated alkaline solutions should not be used to clean whey protein rich fouling deposits. At >0.1 mol L⁻¹ NaOH dissolution and cleaning rates decrease markedly to very low values, particularly at low-mid temperatures. It is shown here that it is caused by the incapacity of the hydroxide ion to destroy non-covalent interactions between protein aggregates at high alkali concentrations. HPLC is used to quantify the breakdown kinetics of soluble whey protein isolate (WPI) aggregates. Results show that the large aggregates breakdown kinetic constant is strongly reduced at >0.25 mol L⁻¹ NaOH, but also at high protein concentrations. Moreover, large aggregates become increasingly stable for long times at ≥0.5 mol L⁻¹ NaOH. The kinetic analysis predicts that large protein aggregates would be fully stable at 0.085–0.105 g WPI/g solution, explaining the dissolution threshold observed in macroscopic swelling studies.

乳制品行业早就知道，不应使用高浓度的碱性溶液来清洁富含乳清蛋白的污垢沉积物。在> 0.1 mol L ^{-1的情况下，} NaOH的溶解和清洁速率会明显降低至非常低的值，尤其是在中低温度下。此处显示这是由于氢氧根离子无法破坏在高碱浓度下蛋白质聚集体之间的非共价相互作用所引起的。HPLC用于量化可溶性乳清蛋白分离物（WPI）聚集体的分解动力学。结果表明，在> 0.25 mol L ^-1 NaOH时，大聚集体的分解动力学常数会大大降低，但在高蛋白浓度下也是如此。此外，大的聚集体在≥0.5mol L ^{-1的情况下}变得越来越稳定氢氧化钠 动力学分析预测大蛋白聚集体在0.085-0.105 g WPI / g溶液下将完全稳定，这解释了宏观溶胀研究中观察到的溶出阈值。