Study On Improving The Stability Of Bovine Milk Immunoglobulins By Microencapsulation

Immunoglobulin(Ig) which produced after the exterior antigen stimulated organism andoccurred immunity reaction is important for the passive protection to human being.Bovinemilk immunoglobulins could be an efficient source of immunoglobulins to use as foodsupplements, however, stability of Ig under food processing and preservation conditions must bedetermined.The objective of this study was to determined the stability of bovine milkimmunoglobulin(IgG) and to improved the stabi1ity by microencapsulation.l. The heat stability and kinetic and thermodynamic~parameters for heat denaturation ofbovine milks IgG were studied. The reaction order is l.5. The rate connstant and activationenergy which calculated for each treatment, provided the theoretical basis for thedetermination of heat treatment conditions during food processing. The optimum kind ofprotector and its' concentration were studied.2. The stability of bovine milk IgG in human digestive system was determined. Thestability of IgG decreased with the decreasing pH values and the increasing content of pepsinand trypsin. At PH 4.0 and above IgG was fai1y resistant to pepsin. IgG was also quite resistantto trypsing digestion. The hydrochloric acid in gastric juice is the main cause of the inactivationof IgG.3. The microcapsules of bovinc milk IgG was made by the method of coacervation andemulsified condensation. The optimal method of making capsules is the emulsifiedcondensation based on the rate of retention of IgG.4. A mathematical moded of the second powder of three was set up in order tostudy the effect of the three factors,concentration of gelatin (A),IgG(B) and emulsifier(C) onthe rate of retention of IgG.The result showed tha the optimum reaction condition were asfol1ows: A=43%,B=3.4%,C=1.25%. The rate of retention in the microcapsules was over 75%.In addition,the pellet size and color were even and stable. The rate of retention, water contentthe solubility of microcapsules were all achieved the design standards. The properties didn'tchange during storage for 3 months. The microcapsules were added to milk to produced yogurt.The app1ied results showed that the product can resistant the heat proces and the change of pHvalue. Therefore, in this experiment, the IgG microcapsules produced by emulsifiedcondensation achieved the reasonable results.Postgraduate: Zbeng Haiying Major: Food ScienceAdvisor: Prof.Yang Tongzhou...