Título del libro: Rheology: Theory, Properties And Practical Applications
Título del capítulo: Phase separation and gelation in mixtures of cross-linked waxy corn starch, whey protein isolate and ?-carrageenan: Viscoelasticity and microstructure
MARIANA RAMIREZ GILLY; ALBERTO TECANTE CORONEL;
Autores externos:
Idioma:
Inglés
Año de publicación:
2013
Palabras clave:
Aggregates; Gelation; Gels; Granulation; Microstructure; Phase separation; Proteins; Sodium chloride; Starch; Two phase flow; Viscoelasticity; Volume fraction; Confocal laser scanning microscopy; Individual components; Synergistic effect; Three-component mixtures; Two-component mixtures; Visco-elastic behaviors; Viscoelastic properties; Whey protein isolate; Binary mixtures
Resumen:
This work deals with aqueous mixtures of cross-linked waxy corn starch (CH10), ?- carrageenan (?C) and whey protein isolate (WPI). The aim was to study the viscoelastic properties and microstructure under conditions for which phase separation and gelation occur. Oscillatory shear tests and confocal laser scanning microscopy were used. The approach was to study the behavior of individual components and two-component mixtures, to understand the behavior of three-component mixtures. Concentrations (wt%) were 1.0 to 4.0 for CH10, 0.25, 0.5, 0.75 and 1.0 for ?C and 0.5, 1.0, 2.0, 3.0, 3.5 to 3.9 for WPI in 100 mM NaCl at pH 7.0. Individual components and mixtures underwent the same thermal treatment. The viscoelastic behavior of starch pastes depended on the volume fraction of swollen granules; different degrees of solid-like behavior were observed. Swollen granules were embedded in a continuous medium. WPI formed solutions or gels depending on its concentration. Aggregates were formed as a previous step to gelation. ?C formed gels of different rigidity depending on its concentration. A continuous phase without network formation was observed. When CH10 was present, two-phase mixtures were formed, either with ?C or with WPI. Synergistic effects existed and were attributed mainly to the volume fraction of swollen granules. Mixtures of WPI and ?C showed phase separation depending on the concentration of each component. This had a noticeable effect on the viscoelastic properties of these mixtures. In threecomponent media, addition of ?C to CH10-WPI mixtures resulted in ?C and WPI aggregates forming the continuous phase. However, for WPI concentrations greater than 2.0%, aggregates were not observed but uniform continuous media between the WPI network and ?C with embedded CH10 granules. Addition of ?C resulted in strong gels, but for WPI concentrations greater than 2.0%, systems behaved like binary mixtures of CH10-WPI. In three-component mixtures, swollen starch granules were surrounded by one-phase media formed when ?C and WPI concentrations were 0.25 and less than 2.0%, respectively. However, for higher concentrations of ?C and WPI, swollen granules were embedded in a two-phase system formed by ?C and WPI. The extent of phase separation depended, however, on the proportion of these two components. Combination of these macromolecules allows a great variety of viscoelastic behaviors and microstructures to be obtained. This in turn permits to understand the way in which these components can be handled to meet desired functions or properties in prepared foods. © 2014 by Nova Science Publishers, Inc. All rights reserved.
Entidades citadas de la UNAM:
ISBN:
9781626189997
Editorial:
Nova Science Publishers, Inc. Nombre de la publicación:
Phase separation and gelation in mixtures of cross-linked waxy corn starch, whey protein isolate and ?-carrageenan: Viscoelasticity and microstructure
Página inicial:
301
Página final:
328
Tipo de producto:
Capítulo de un Libro
