Fibrillation of β-lactoglobulin at low pH in the presence of a complexing anionic polysaccharide.
The influence of electrostatic complexation with κ-carrageenan was tested on the fibrillation process of β-lactoglobulin at pH 2.0. Morphology and structural development were monitored through cross correlation dynamic light scattering, transmission electron microscopy, and atomic force microscopy. Scattering indicated that noncomplexed β-lactoglobulin monomers aggregated to form fibrils after 15-90 min of heating at 90 °C. However, electrostatic protein-carrageenan complexes found in the unheated system were unchanged by the thermal process. Images and scattering results showed that carrageenan complexes slowed fibrillation kinetics, possibly through reduction in available monomer concentration. Complexes adhered to fibrils at ends and junctions in TEM images, indicating interactive affinity with the fibers, presumably as heterogeneous nucleation sites.
ETH Zurich, Food and Soft Materials Laboratory, Institute of Food, Nutrition & Heath, Schmelzbergstrasse 9, LFO E22, 8092 Zurich, Switzerland.
Owen G
OG
Jones
Jozef
J
Adamcik
Stephan
S
Handschin
Sreenath
S
Bolisetty
Raffaele
R
Mezzenga
D002351:Carrageenan / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007782:Lactoglobulins / Q000737:chemistry* / Q000378:metabolism; D009994:Osmolar Concentration; D055503:Protein Multimerization / Q000187:drug effects*; D020836:Protein Structure, Quaternary; D055672:Static Electricity; D013431:Sulfates; D013696:Temperature
D007782:Lactoglobulins; D013431:Sulfates; D002351:Carrageenan