酪蛋白在不同pH值下特性的研究  

Research on the Characteristic of Caseins at Different pH

作　　者：赵正涛[1] 李全阳[1] 赵红玲[1] 王婷婷[1] 

机构地区：[1]山东农业大学食品学院,山东泰安271000

出　　处：《乳业科学与技术》2009年第1期26-29,共4页JOURNAL OF DAIRY SCIENCE AND TECHNOLOGY

基　　金：中国博士后科学基金资助项目(20070411100);山东省自然科学基金资助项目(2007ZRB02217)。

摘　　要：将高速离心分离的酪蛋白配制成不同pH值的溶液,然后研究了酪蛋白的Zeta电势、电导率、黏度、平均粒径和稳定性的变化规律。实验结果表明,酪蛋白溶液的Zeta电势值(绝对值)、电导率值和黏度值都是随着pH的增加而逐渐增加。平均粒径值是先减小后增加,在pH 6.2时有最小值,为26.03 nm。溶液的pH在5.8-6.6之间时,体系较稳定。初步认为,当pH小于7时,降低pH会导致胶体磷酸钙的溶解,使得体系的平均粒径变小。继续降低pH会导致静电斥力的减小,酪蛋白会发生凝集,平均粒径增大,体系也会变得不稳定。Caseins received by high speed centrifugation were made into solutions with different pH. And the change law of Zeta potential, conductance, viscosity, average particle radius and stability were investigated. The result showed that Zeta potential value （absolute value）, conductance value and viscosity value increased gradually with the adding of pH. The average particle size first decreased and then increased and had the minimal value at pH 6.2, which was 26.03 nm. Solutions with the pH between 5.8 and 6.6,systems were more stable. The preliminary view suggested that when pH is less than 7, the reduction of pH result in the dissolve of colloid calcium phosphate and diminish of average particle size. The continuative decrease of pH could diminish the static exclude strength, which made the coagulation of caseins. So the average particle size increased and systems became instability.

关 键 词：牛乳 酪蛋白 平均粒径 Zeta电势 稳定性 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]