Biomaterial Database

Kappa-casein micelles: structure, interaction and gelling studied by small-angle neutron scattering. 1991

C G de Kruif, and R P May

Netherlands Institute for Dairy Research, Ede.

Small-angle neutron scattering (SANS) measurements on dilute and concentrated dispersions of kappa-casein micelles in a buffer at pH = 6.7 were made using the D11 diffractometer in Grenoble. Results indicate that the micelles have a dense core with a fluffy outer layer. This outer layer appears to give rise to a steeply repulsive interaction on contact. In fact, the hard-sphere model best fits the measured scattering intensities. Adding chymosin to the dispersion initiated a fractal flocculation of the micelles and consecutively a coalescence of the micelles. This unexpected second process resembled that of spinodal demixing. The dispersion phase thus separates into a water and a protein phase on a time scale of hours. The observed phenomona contribute to the understanding of the cheese-making process.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008823	Micelles	Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.	Micelle
D009502	Neutrons	Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.	Neutron
D012085	Chymosin	The predominant milk-clotting enzyme from the true stomach or abomasum of the suckling calf. It is secreted as an inactive precursor called prorennin and converted in the acid environment of the stomach to the active enzyme. EC 3.4.23.4.	Rennin,Chymosin A,Chymosin C
D002364	Caseins	A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.	alpha-Casein,gamma-Casein,AD beta-Casein,Acetylated, Dephosphorylated beta-Casein,Casein,Casein A,K-Casein,Sodium Caseinate,alpha(S1)-Casein,alpha(S1)-Casein A,alpha(S1)-Casein B,alpha(S1)-Casein C,alpha(S2)-Casein,alpha-Caseins,beta-Casein,beta-Caseins,epsilon-Casein,gamma-Caseins,kappa-Casein,kappa-Caseins,AD beta Casein,Caseinate, Sodium,K Casein,alpha Casein,alpha Caseins,beta Casein,beta Caseins,beta-Casein Acetylated, Dephosphorylated,beta-Casein, AD,epsilon Casein,gamma Casein,gamma Caseins,kappa Casein,kappa Caseins
D006020	Glycopeptides	Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.	Glycopeptide
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D012542	Scattering, Radiation	The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Radiation Scattering,Radiation Scatterings,Scatterings, Radiation