Further observations on the size, shape, and hydration of casein micelles from novel analytical ultracentrifuge and capillary viscometry approaches.
The size, shape, and hydration of casein micelles were estimated using a combination of sedimentation velocity (time-derivative analysis) in the analytical ultracentrifuge and capillary viscometry applied to skimmed milk. On the basis of sedimentation time-derivative and Wales-van Holde analyses the casein micelles appear as large spherical molecules of s0T,b = 845S, Mw approximately 2.8 x 10(8), hydrodynamic radius approximately 77.8 nm, and ks/[eta] = 1.6. The molecular hydration (i.e., the extent of chemically bound and physically entrained solvent) was calculated to be 3.4 g/g. These results appear to be in good agreement with comparable results from electron microscopy and dynamic light scattering.
Morris
G A
GA
NCMH Unit, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, U.K. scxgam@nottingham.ac.uk
Foster
T J
TJ
Harding
S E
SE
D000465:Algorithms; D002364:Caseins / Q000737:chemistry*; D008823:Micelles; D008970:Molecular Weight; D014461:Ultracentrifugation; D014783:Viscosity
D002364:Caseins; D008823:Micelles