摘要
采用动态光散射技术考察了酪蛋白胶束在各种物化条件(温度、浓度、pH、离子强度、乙醇)下的聚集行为,并测定了胶束尺寸。结果表明:热处理导致酪蛋白胶束发生离解,平均流体力学半径(Rh)值不断减小,且当蛋白浓度较低时热离解过程为可逆,而浓度较高时则为不可逆;酪蛋白胶束的Rh值随蛋白浓度及离子强度的增加均呈现先减小后逐渐增大的趋势,并分别在2g/L和0.1mol/L时达到最小值;而Rh值随pH值的增加则先增大再逐渐减小,并在pH7.0时达到最大值;添加乙醇使酪蛋白胶束不断聚集,Rh值逐渐增加,溶液散射光强(Iθ)呈指数增长。
To better understand what happens to the structure of casein, the effects of various protein-solution interactive forces induced from physicochemical conditions （temperature, concentration, pH, ionic strength and ethanol） on the molecular sizes and aggregation behaviors of casein micelles have been investigated by dynamic light scattering. The average hydrodynamic radius （Rh ） of casein micelles decreased generally with increasing temperature, indicating the dissociation of casein micelles. It was a reversible dissociation for thermal treatment of casein with a lower concentration, while the heat-induced dissociation of casein with a higher concentration was irreversible. With the increase of concentration and ionic strength, the Rh value of casein micelles firstly decreased then increased, and achieved the minimum at 2 g/L and 0. 1 mol/L respectively. On the contrary, the Rh value underwent an opposite plot with increasing pH and obtained the maximum at pH 7.0. When the proportion of ethanol in the solvent increased from 0 to 40%, the Rh value of protein molecules increased gradually and the light scattering intensity （Iθ） of casein solution displayed an exponential growth, which suggested the aggregation of casein micelles.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2007年第6期809-813,共5页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No20306023)
高等学校博士学科点专项科研基金(No20050056061)资助
关键词
酪蛋白
胶束
流体力学半径
动态光散射
Casein, micelles, hydrodynamic radius, dynamic light scattering
