Abstract
Gum arabie, a natural polysaccharide derived from exudates of Acacia senegal and Acacia seyal trees, is a commonly used food hydrocolloid. The complex chemical structure of the gum has been widely studied revealing a multifraction material consisting mainly of a highly branched polysaccharide and a protein-polysaccharide complex (GAGP) as a minor component. This work investigates its mesoscopic structure in aqueous solution by small-angle X-ray and neutron scattering combined with cryotransmission electrons microscopy. Scattering measurements reveal an intricate shape composed of many spheroidal aggregates assigned to the polysaccharide with a small amount of larger coils. A scattering peak is observed at moderate to high concentrations, the spacing of which exhibits a c-1/3 power law relation to polymer concentration (c). Upon addition of salt, this peak disappears, indicating its electrostatic nature. The large coils contribute a q-2 power law at the low scattering vector (q) range. However, at low concentration in which the interaggregate peak is not observed, a q-1 power law at the low q range indicates the possible existence of a fraction with a locally extended conformation.
Original language | English |
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Pages (from-to) | 3265-3271 |
Number of pages | 7 |
Journal | Journal of Polymer Science, Part B: Polymer Physics |
Volume | 44 |
Issue number | 22 |
DOIs | |
State | Published - 15 Nov 2006 |
Keywords
- Gum arabic
- Hyperbranched
- Neutron scattering
- Polysaccharides
- SAXS
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Polymers and Plastics
- Materials Chemistry