Journal article

Texture and rheological characterization of kappa and iota carrageenan in the presence of counter ions

TR Thrimawithana, S Young, DE Dunstan, RG Alany

Carbohydrate Polymers | Published : 2010

Abstract

The effect of cation concentration and ion valency (0-0.2% (w/v) of KCl or CaCl2·2H2O) on the mechanical, micro-structural and rheological properties of aqueous kappa (κ) and iota (ι) carrageenan dispersions were investigated using a texture analyzer, cryo-SEM and an oscillatory rheometer, respectively. The probe penetration method demonstrated a decrease in "hardness" of carrageenan systems with increasing cation concentration, after exhibiting an initial maximum. The Young's modulus (E) of κ-carrageenan gels was determined using the uniaxial compression method. E was approximately 3 times the shear modulus recorded under the same experimental conditions; indicating the elimination of slip ..

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University of Melbourne Researchers

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Funding Acknowledgements

The authors would like to thank CP Kelco, Denmark for kindly donating the carrageenan samples and the University of Auckland for their financial support in the form of a doctoral scholarship for Mrs Thilini Thrimawithana. The authors also appreciate the skilled assistance of Ms Catherine Hobbis at the Department of Chemical and Material Engineering, University of Auckland, New Zealand in Cryo-SEM imaging. Special thanks also go to Mr Adam Kilcullen and Mr Stephen Tanurdjaja at the Department of Chemical and Biomolecular Engineering in University of Melbourne, Australia for their kind assistance with rheological measurements.