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Gélification et séparation de phase dans les mélanges protéines globulaires/pectines faiblement méthylées selon les conditions ioniques

Abstract : Heat-induced gelation of globular protein (bovine serum albumin (BSA) and β-Lactoglobulin) mixed with low methoxyl pectin (LM pectin) was studied by rheology and confocal laser scanning microscopy coupled with texture image analysis using the co-occurrence method. Properties of individual biopolymers were also described. The difference between the two globular proteins in the mixture was also evaluated. The structure of BSA gels, characterized by light scattering, depended strongly on NaCl or CaCl₂ content. In the mixture, a competition between protein gelation and phase separation kinetics was evidenced. The control of the kinetics depends on intrinsic and extrinsic factors and especially on the nature and content of added salt. Increasing LM pectin concentration results in a more pronounced phase separation. Depending on biopolymer concentrations and the nature of salt in the medium, protein gels is weakened or strengthened by the presence of the polysaccharide. In presence of calcium, both biopolymers have a specific affinity for this cation that is traduced, for LM pectin, by its ability to form a gel. In the mixture, a composite gel is formed. Depending on NaCl content, gelation of the system is governed either by protein or LM pectin gelation. From all the results obtained, a schematic interpretation of mechanism implied in the formation of mixed gels during the heating process was proposed based on phase separation and gelation of biopolymers.
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https://pastel.archives-ouvertes.fr/pastel-00003705
Contributor : Ecole Agroparistech <>
Submitted on : Monday, June 2, 2008 - 8:00:00 AM
Last modification on : Saturday, June 6, 2020 - 5:50:25 PM
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  • HAL Id : pastel-00003705, version 1
  • PRODINRA : 246684

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Laurence Donato. Gélification et séparation de phase dans les mélanges protéines globulaires/pectines faiblement méthylées selon les conditions ioniques. Sciences du Vivant [q-bio]. ENSIA (AgroParisTech), 2004. Français. ⟨NNT : 2004EIAA0142⟩. ⟨pastel-00003705⟩

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