Jamming and gelation of dense beta-casein micelle suspensions.
The rheology of dense suspensions of beta-casein micelles is investigated at pH 6. For a given temperature, the viscosity increases dramatically at a critical concentration (Cc) of about 100 g/L due to jamming of the micelles. For a given concentration close to and above Cc, the viscosity of dense suspensions decreases strongly with increasing temperature because Cc increases. The suspensions show weak shear thickening followed by strong shear thinning. At lower pH, that is, closer to the isoelectric point, spontaneous gelation is observed, which is favored by lowering the temperature and addition of sodium polyphosphate. The gelation process is studied at pH 5.5 by rheology and light scattering.
Panouillé
Maud
M
Polymères, Colloïdes, Interfaces, Unite mixté de recherche, Centre National de la Recherche Scientifique, Université du Maine, 72085 le Mans Cedex 9, France.
Durand
Dominique
D
Nicolai
Taco
T
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002364:Caseins / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry*; D008823:Micelles; D008894:Milk Proteins / Q000737:chemistry; D011122:Polyphosphates / Q000737:chemistry; D012542:Scattering, Radiation; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors
D001672:Biocompatible Materials; D002364:Caseins; D046911:Macromolecular Substances; D008823:Micelles; D008894:Milk Proteins; D011122:Polyphosphates; C005692:triphosphoric acid