Effects of the environmental factors on the casein micelle structure studied by cryo transmission electron microscopy and small-angle x-ray scattering/ultrasmall-angle x-ray scattering

Effects of the environmental factors on the casein micelle structure studied by cryo transmission electron microscopy and small-angle x-ray scattering/ultrasmall-angle x-ray scatterin

Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies

Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies. 9. International Conference on Agri-Food Antibodie

Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies

 Format du poster : 21 X 29,7Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies. 9. International Conference on Agri-Food Antibodie

Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies

Topology of the Casein micelle surface on Biacore Using specific monoclonal antibodies. 9. International Conference on Agri-Food Antibodie

Topography of the casein micelle surface by surface plasmon resonance (SPR) using a selection of specific monoclonal antibodies

Contact: [email protected] theoretical models of the casein micelle structure have been proposed in the past, but the exact organization of the four individual caseins (Rs1, Rs2, β, and k) within this supramolecular structure remains unknown. The present study aims at determining the topography of the casein micelle surface by following the interaction between 44 monoclonal antibodies specific for different epitopes of Rs1-, Rs2-, β-, and k-casein and the casein micelle in real time and no labeling using a surface plasmon resonance (SPR)-based biosensor. Although the four individual caseins were found to be accessible for antibody binding, data confirmed that the C-terminal extremity of k-casein was highly accessible and located at the periphery of the structure.When casein micelles were submitted to proteolysis, the C-terminal extremity of k-casein was rapidly hydrolyzed. Disintegration of the micellar structure resulted in an increased access for antibodies to hydrophobic areas of Rs1- and Rs2-casei

Addition of citrate to casein micelles: Modifications of their physico-chemistry and acid gelation.

The organization and functional properties of casein micelles (CMs) are influenced by several factors such as temperature, pH, and ionic environment. In this study, different CMs suspensions were obtained by addition of citrate to milk at final added concentrations: 8.5, 14.5 and 18.7 mM and readjustment of pH to 6.75. Modified milks were concentrated by ultrafiltration at ~10°C and some samples were then diafiltered against milk ultrafiltrate and standardized at ~45 g.kg-1 total proteins. The analyses revealed that CMs were demineralized in Ca and P and dissociated. After acidification to pH 4.6 by HCl, set-style gels from samples containing 8.5 and 18.7 mM added citrate have a firmness reduced to 75 and 56% of that of the gel from the control sample, respectively (without citrate). In the opposite, the firmness obtained after addition of 14.5 mM of citrate increased to 116% of the value of the control sample. Same trends were observed with the viscosity values determined on the different stirred acid gels. For both rheological analyses, the comparison of diafiltered samples against undiafiltered samples did not show significant differences. These changes in the rheological properties of acid gels were probably related to the modifications of the micellar calcium phosphate responsible for the structure of CMs

Addition of citrate to casein micelles: Modifications of their physico-chemistry and acid gelation.

The organization and functional properties of casein micelles (CMs) are influenced by several factors such as temperature, pH, and ionic environment. In this study, different CMs suspensions were obtained by addition of citrate to milk at final added concentrations: 8.5, 14.5 and 18.7 mM and readjustment of pH to 6.75. Modified milks were concentrated by ultrafiltration at ~10°C and some samples were then diafiltered against milk ultrafiltrate and standardized at ~45 g.kg-1 total proteins. The analyses revealed that CMs were demineralized in Ca and P and dissociated. After acidification to pH 4.6 by HCl, set-style gels from samples containing 8.5 and 18.7 mM added citrate have a firmness reduced to 75 and 56% of that of the gel from the control sample, respectively (without citrate). In the opposite, the firmness obtained after addition of 14.5 mM of citrate increased to 116% of the value of the control sample. Same trends were observed with the viscosity values determined on the different stirred acid gels. For both rheological analyses, the comparison of diafiltered samples against undiafiltered samples did not show significant differences. These changes in the rheological properties of acid gels were probably related to the modifications of the micellar calcium phosphate responsible for the structure of CMs