Phase-separated biopolymer mixture rheology: Prediction using a viscoelastic emulsion model

Stokes, J. R., Wolf, B. and Frith, W. J. (2001) Phase-separated biopolymer mixture rheology: Prediction using a viscoelastic emulsion model. Journal of Rheology, 45 5: 1173-1191. doi:10.1122/1.1389314

Author Stokes, J. R.
Wolf, B.
Frith, W. J.
Title Phase-separated biopolymer mixture rheology: Prediction using a viscoelastic emulsion model
Journal name Journal of Rheology   Check publisher's open access policy
ISSN 0148-6055
Publication date 2001
Sub-type Article (original research)
DOI 10.1122/1.1389314
Volume 45
Issue 5
Start page 1173
End page 1191
Total pages 19
Place of publication New York
Publisher American Institute of Physics
Language eng
Subject 09 Engineering
Abstract The relationship between the morphology and rheology of phase-separated biopolymer mixtures is investigated. Biopolymer mixtures, which are utilized in the food industry for their textural and structuring properties, often phase separate and demix to form water-in-water emulsions. Controlling the morphology of biopolymer mixtures during flow processing and inducing gelation of one or both phases lead to products with novel microstructures and material properties [B. Wolf et ai., Food Hydrocolloids 14, 217-225 (2000)]. An emulsion model [J. F. Palierne, Rheol. Acta 29, 204-214 (1990)], commonly used for the prediction of the linear viscoelastic properties of polymer blends, is used here to relate the rheology to the morphology of water-in-water emulsions. The system under investigation is a gelatin-maltodextrin mixture which phase separates at 60 degreesC for particular concentrations, characterized by a binodal curve, into a gelatin-rich and maltodextrin-rich phase. Emulsions with phase volumes of 10% and 30% were examined with either phase as the dispersed phase. The morphology varies with the preshear rate such that the radius of droplets after a preshear of 10 s(-1) is around 20-50 mum while after a preshear of 100 s(-1) the droplets are typically less than 10 mum. Despite the low viscosity, elasticity, and interfacial tension of the gelatin-maltodextrin emulsion, the emulsion model is found to predict the rheology and morphology of the mixtures subjected to preshear rates of 1-100 s(-1). The interfacial tension for the gelatin-maltodextrin system studied is approximately 50 muN/m at 60 degreesC. (C) 2001 The Society of Rheology.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Chemical Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 28 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 01 Jul 2009, 16:05:23 EST