title: Complexation of β-lactoglobulin fibrils and sulfated polysaccharides.
abstract: Fibrils of β-lactoglobulin, formed by heating at pH 2, were titrated with a sulfated polysaccharide (κ-carrageenan) to determine the morphology and mechanism of complex formation at low pH. Structural information on the resultant complexes was gathered using transmission electron microscopy, atomic force microscopy, Doppler electrophoresis, and small-angle neutron scattering. Electrophoresis demonstrated that the carrageenan complexed with protein fibrils until reaching a maximum complexation efficiency at a protein/polysaccharide (r) weight ratio of 5:3. Neutron scattering and microscopy indicated an increasing formation of spherical aggregates attached along the protein fibrils with increases in the carrageenan concentration. These globular particles had an average diameter of 30 nm. Small-angle neutron scattering of these complexes could be accurately described by a form factor corresponding to multistranded twisted ribbons with spherical aggregates along their contour length, arranged in a necklace configuration.
authors.affiliation: ETH Zurich, Food and Soft Materials Laboratory, Institute of Food, Nutrition & Health, Schmelzbergstr. 9, LFO E22, 8092 Zurich, Switzerland.
authors.forename: Owen G
authors.initials: OG
authors.lastname: Jones
authors.forename: Stephan
authors.initials: S
authors.lastname: Handschin
authors.forename: Jozef
authors.initials: J
authors.lastname: Adamcik
authors.forename: Ludger
authors.initials: L
authors.lastname: Harnau
authors.forename: Sreenath
authors.initials: S
authors.lastname: Bolisetty
authors.forename: Raffaele
authors.initials: R
authors.lastname: Mezzenga
mesh_terms: D002351:Carrageenan / Q000737:chemistry; D004586:Electrophoresis / Q000379:methods; D007782:Lactoglobulins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D011134:Polysaccharides / Q000737:chemistry*; D012542:Scattering, Radiation; D013431:Sulfates / Q000737:chemistry*
chemical_list: D007782:Lactoglobulins; D011134:Polysaccharides; D013431:Sulfates; D002351:Carrageenan