The Study On Dissolve Process And The Aggregation Of Casein Solution

The effect of concentration, time, temperature and Cu2+ on the viscosity of the casein molecule was investigated systematically by viscosity method. The conformation of casein was studied by DLS and GPC. And the polarity of hydrophobic microdomain of casein and grafted casein in solution was studied using pyrene as fluorescence probe.The results indicated that viscosity of casein solution is lower and the casein is separated when the concentration of casein solution is lower than Cs. The viscosity of solution increases sharply because the chains of molecule tangle each other when the concentration of solution is higher than C*. Along with the time goes the sub-units of casein apart step by step and viscosity decrease. Cu2+ act mainly on inner of separated casein molecule and make the tangle in it more acute when the concentration ofsolution is lower than C*. Cu act mainly between the chains of casein molecule and make the tangle between them more acute when the concentration of solution is higher than C*. The viscosity of casein solution decreased with increasing the temperature. The separation of sub-unit of casein molecule is approved by DLS and GPC. Pyrene was aneffective fluorescence probe for detecting the hydrophobic microdomain of casein in solution. The hydrophobic microdomain of casein solution exhibited different polarity at different pH values. After the graft-copolymerization of methyl methacrylate (MMA) onto casein, the hydrophobic microdomain increased and the polarity decreased, indicating that the graft-copolymerization took place in the hydrophobic microdomain.