Abstract Ultrahigh temperature (UHT) processed and lactose-free milk are for export to Eastern markets. Free galactose and glucose in lactose-free milk increase occurrence of Maillard products and hence lower milk quality. Notably, enzymatic conversion of galactose into galacto-oligosaccharides (GOS) mitigates such undesirable reactions. As little is known about the effect of GOS on caseins, interactions between caseins in presence or absence of GOS or lactose were assessed by surface plasmon resonance analysis. Based on steady state binding constants (KD) soluble αS-casein showed one order of magnitude lower affinity than soluble β-casein and κ-casein for chip-immobilised αS- and β-casein. By contrast, αS-casein had higher affinity for immobilised κ-casein, followed by β- and κ-casein. The interaction between the caseins did not obey a 1:1 binding model and it was not possible to calculate a precise stoichiometry. Importantly, lactose and GOS exerted very modest or no effect on the various interaction between the caseins.

中文翻译：

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使用表面等离子体共振分析存在乳制品相关碳水化合物时的酪蛋白-酪蛋白相互作用

摘要 超高温（UHT）加工和无乳糖牛奶出口到东方市场。无乳糖牛奶中的游离半乳糖和葡萄糖会增加美拉德产品的发生率，从而降低牛奶质量。值得注意的是，将半乳糖酶促转化为低聚半乳糖 (GOS) 可以减轻此类不良反应。由于对 GOS 对酪蛋白的影响知之甚少，因此通过表面等离子体共振分析评估了存在或不存在 GOS 或乳糖时酪蛋白之间的相互作用。基于稳态结合常数 (KD)，可溶性 αS-酪蛋白对芯片固定的 αS- 和 β-酪蛋白显示出比可溶性 β-酪蛋白和 κ-酪蛋白低一个数量级的亲和力。相比之下，αS-酪蛋白对固定化的κ-酪蛋白具有更高的亲和力，其次是β-和κ-酪蛋白。酪蛋白之间的相互作用不服从 1：1 结合模型，不可能计算出精确的化学计量。重要的是，乳糖和 GOS 对酪蛋白之间的各种相互作用影响很小或没有影响。