Effect of pH and ionic strength on apple juice turbidity: Application of the extended DLVO theory

This work studied the effect of liquid medium pH and ionic strength on the stability of apple juice particles. Colloidal interactions between them were modeled with the extended DLVO theory. Considering that repulsive forces provide sol stability, its turbidity was modeled to be the sum of a "h...

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Detalles Bibliográficos
Autores: Benitez, Elisa Ines, Genovese, Diego Bautista, Lozano, Jorge Enrique
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/60131
Acceso en línea:http://hdl.handle.net/11336/60131
Access Level:acceso abierto
Palabra clave:Apple Juice
Dlvo Theory
Ionic Strength
Ph
Stability
Turbidity
https://purl.org/becyt/ford/2.11
https://purl.org/becyt/ford/2
Descripción
Sumario:This work studied the effect of liquid medium pH and ionic strength on the stability of apple juice particles. Colloidal interactions between them were modeled with the extended DLVO theory. Considering that repulsive forces provide sol stability, its turbidity was modeled to be the sum of a "hydration contribution" plus an "electrostatic contribution". Sol turbidity followed a linear relationship with the energy barrier between pairs of particles, which prevents their agglomeration (energy barrier information was obtained from viscosity-particle volume fraction data). The turbidity predicted for zero energy barrier was significantly high, indicating that particles were inherently stable. This was attributed to an immobilized water layer coating them (the primary hydration shell). Energy barrier was governed by changes in particles surface charge (ζ potential) and hydration constant: they decreased at decreasing pH and increasing ionic strength. ζ potential's reduction was attributed to neutralization of particles negative charge, and compression of the electrical double layer surrounding them, respectively. Hydration's decrease was attributed to the distortion of the outer hydration shells by hydrated cations attracted by particles negative charge. © 2006 Elsevier Ltd. All rights reserved.