Open Accessκ‐Casein micelles: structure, interaction and gelling studied by small‐angle neutron scattering
Author(s) -
KRUIF Cees G.,
MAY Roland P.
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb16201.x
Subject(s) - micelle , small angle neutron scattering , neutron scattering , coalescence (physics) , flocculation , materials science , scattering , chemical physics , chymosin , phase (matter) , dispersion (optics) , fractal dimension , spinodal , chemical engineering , crystallography , chemistry , casein , analytical chemistry (journal) , fractal , chromatography , optics , aqueous solution , physics , organic chemistry , mathematical analysis , mathematics , engineering , astrobiology
Small‐angle neutron scattering (SANS) measurements on dilute and concentrated dispersions of κ‐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. 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.