酸性条件下酪蛋白与高酯果胶稳定体系的研究

Stability of casein and high-ester pectin in acid conditions

【目的】研究酸性条件下酪蛋白的稳定特性。【方法】从牛乳中提取出纯体酪蛋白，对酸性条件下酪蛋白与高酯果胶相互作用的条件和机理进行了测定与分析。【结果】当pH值为4．20，酪蛋白含量为0．6％～1．5％时，高酯果胶添加量（y）与酪蛋白含量（z）之间存在线性关系，线性方程为y=0．3333x＋0．2458；酪蛋白和高酯果胶有效结合的适宜pH值为3．70～5．30。【结论】在合适的酸度范围内，高酯果胶分子通过空间位阻效应和静电吸引与酪蛋白胶束结合，阻止了酪蛋白胶束之间的聚集沉淀，从而使酪蛋白在酸性条件下也可以相对稳定地存在。

[Objective] This paper studied the stability of Casein in acid conditions. [Method] Casein was extracted from milk,and the requirments and mechanism of interaction between Casein and High-ester Pectin in different acid conditions were tested and analysed. [Result] It shows that the relationship between Content of Casein （x） and Dosage of High-ester Pectin （y） was linear when the content of casein changed from 0.6% to 1.5% and pH value was 4.20,the linearity equation was y=0. 333 3x＋0. 245 8. The effective pH values of combination were from 3.70 to 5.30. [Conclusion] In these acid conditions, High-ester Pectin interacted with Casein by steric stabilization and electrostatic attration,which could keep casein from coagulating and be stable.