Irreversible self-assembly of ovalbumin into fibrils and the resulting network rheology.
The self-assembly of ovalbumin into fibrils and resulting network properties were investigated at pH 2, as a function of ionic strength. Using transmission electron microscopy (TEM), the effect of ovalbumin concentration on the contour length was determined. The contour length was increasing with increasing ovalbumin concentration. TEM micrographs were made to investigate the effect of ionic strength on the contour length. In the measured ionic strength regime (0.01-0.035 M) fibrils of approximately equal length (+/-200 nm) were observed. TEM micrographs showed that the contour length of the fibrils, versus time after dilution, remained constant, which indicates that the self-assembly of ovalbumin is irreversible. Using the results of rheological measurements, we observed a decreasing critical percolation concentration with increasing ionic strength. We explain this result in terms of an adjusted random contact model for charged semiflexible fibrils. Hereby, this model has now been proven to be valid for fibril networks of beta-lg, BSA and, currently, for ovalbumin.
Food Physics Group, Department of Agrotechnology and Food Sciences, Wageningen University, P.O. Box 8129, Wageningen, EV 6700, The Netherlands.
Cecile
C
Veerman
Geertje
G
de Schiffart
Leonard M C
LM
Sagis
Erik
E
van der Linden
D006863:Hydrogen-Ion Concentration; D008854:Microscopy, Electron; D008956:Models, Chemical; D008958:Models, Molecular; D009994:Osmolar Concentration; D010047:Ovalbumin / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D012212:Rheology
D010047:Ovalbumin