Skip to main content

Research Repository

Advanced Search

The influence of charge on the multiple thermal transitions observed in xanthan

Abbaszadeh, A.H.; Lad, M.; Morris, G.A.; MacNaughtan, W.; Sworn, G.; Foster, T.J.

Authors

A.H. Abbaszadeh

M. Lad

G.A. Morris

W. MacNaughtan

G. Sworn

T.J. Foster



Abstract

Helix-coil transitions in xanthans occur at lower temperatures when the pyruvate group is charged, destabilising the polymer chains. Increasing salt content increases the transition temperature by reducing the effective charge on the pyruvate. A simple equivalent mass action model predicts how transition temperatures change as a function of salt concentration. The functional form of the change in transition temperature (1/T) versus natural log (salt concentration) is approximately linear and similar to more traditional polyelectrolyte theories. Transition temperatures in xanthans containing nominally homogeneous pyruvate contents show biphasic transitions, this is because the phases contain different pyruvate levels, however the transitions approach one another in temperature and eventually merge as salt content is increased. It is proposed that pyruvate groups, despite being present at a lower concentration relative to glucuronic acid, dominate the charge interactions due to their location on the outside of the helices.

Citation

Abbaszadeh, A., Lad, M., Morris, G., MacNaughtan, W., Sworn, G., & Foster, T. (2019). The influence of charge on the multiple thermal transitions observed in xanthan. Food Hydrocolloids, 97, Article 105184. https://doi.org/10.1016/j.foodhyd.2019.105184

Journal Article Type Article
Acceptance Date Jun 24, 2019
Online Publication Date Jun 25, 2019
Publication Date Dec 1, 2019
Deposit Date Sep 17, 2019
Publicly Available Date Mar 29, 2024
Journal Food Hydrocolloids
Print ISSN 0268-005X
Electronic ISSN 1873-7137
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 97
Article Number 105184
DOI https://doi.org/10.1016/j.foodhyd.2019.105184
Keywords Food Science; General Chemistry; General Chemical Engineering
Public URL https://nottingham-repository.worktribe.com/output/2625248
Publisher URL https://www.sciencedirect.com/science/article/pii/S0268005X18313614

Files




You might also like



Downloadable Citations