title: Thermal gelation of mixed egg yolk/kappa-carrageenan dispersions.
abstract: This study aims to evaluate the effect of gum content and pH on the thermal gelation of mixed egg yolk/κ-carrageenan (EY/κC) dispersions, monitored by linear viscoelastic measurements. Heat processing induces dramatic changes in the microstructure and viscoelastic properties of EY/κC systems, which may be attributed to a multistage mechanism that yields an interparticle gel network. An increase in κC content generally induces an enhancement in viscoelasticity. A reduction in pH hinders this enhancement and causes an anticipation of the multistage process, which confirms the importance of the electrostatic interactions of EY/κC dispersions. The viscoelastic properties of EY/κC gels generally fit a master mechanical spectrum, which suggests that the protein matrix generally dominates the microstructure of EY/κC gels. However, SEM images reveal formation of a κC network at low pH, at which some κC autohydrolysis may also play a role. Electrostatic attractions seem to favour interactions among EY aggregates and κC into the carrageenan network.
authors.affiliation: Departamento de Ingeniería Química, Universidad de Sevilla, Escuela Politécnica Superior, 41011 Sevilla, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Aguilar
authors.affiliation: Departamento de Ingeniería Química, Universidad de Sevilla, Escuela Politécnica Superior, 41011 Sevilla, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Cordobés
authors.affiliation: LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada de Ajuda, 1349-017 Lisboa, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Raymundo
authors.affiliation: Departamento de Ingeniería Química, Universidad de Sevilla, Escuela Politécnica Superior, 41011 Sevilla, Spain. Electronic address: aguerrero@us.es.
authors.forename: A
authors.initials: A
authors.lastname: Guerrero
mesh_terms: D002351:Carrageenan / Q000737:chemistry*; D004530:Egg Yolk / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D006358:Hot Temperature; D014783:Viscosity
chemical_list: D005782:Gels; D002351:Carrageenan
keywords: Egg yolk; Protein-polysaccharide interactions; Scanning electron microscopy; Small amplitude oscillatory shear; Thermal gelation; κ-Carrageenan