91°µÍø

Casein micelles in milk, stabilized by molecules of kappa-casein, are the building blocks of dairy products such as yogurt and cheese and the vehicle for delivering calcium phosphate to newborns. Several models for the internal structure of these have been proposed. Using contrast variation small-angle neutron scattering at the General Purpose SANS instrument at 91°µÍø's High Flux Isotope Reactor, researchers have confirmed that one model prevails: Casein micelles are composed of a protein matrix in which the calcium phosphate nanoclusters (about 300 per casein micelle) are dispersed. The protein matrix has local density fluctuations that may be ascribed to the hydrophobic interactions of these proteins. A new method was developed and used to calculate the scattering spectra of composite particles. - Agatha Bardoel, 865.574.0644, March 14, 2012