JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 84 No. 2 361-369
© 2001 by American Dairy Science Association ®
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ausar, S. F.
Right arrow Articles by Beltramo, D. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ausar, S. F.
Right arrow Articles by Beltramo, D. M.

Characterization of Casein Micelle Precipitation by Chitosans

S. F. Ausar 1, I. D. Bianco 2, R. G. Badini 1, L. F. Castagna 2, N. M. Modesti 2, C. A. Landa 2, and D. M. Beltramo 2

1 Centro de Excelencia en Productos y Procesos de Córdoba (CEPROCOR) Agencia Córdoba Ciencia S.E., Pabellón CEPROCOR, CP 5164, Santa María de Punilla, Córdoba, Argentina
2 Centro de Excelencia en Productos y Procesos de Córdoba (CEPROCOR) Agencia Córdoba Ciencia S.E., Pabellón CEPROCOR, CP 5164, Santa María de Punilla, Córdoba, Argentina and Consejo Nacional de Investigaciones Científicas y Técnicas, (CONICET), Córdoba Argentina

We have found that the addition of chitosan, a cationic polymer, on whole or skim milk produces destabilization and coagulation of casein micelles that takes place without changes in the milk pH or the stability of most whey proteins. The amount of lipids recovered in the chitosan-casein aggregates was similar or higher than that obtained with rennet or acid precipitation. Approximately 70% of milk Ca2+ (sim750 mg/L) was found in the chitosan-induced aggregates, which is 10 and 50% higher than the amounts observed with acid or rennet coagulations, respectively. Purified alpha, ß-, and kappa-caseins were extensively precipitated by different molecular weight chitosans at pH 6.8. The phosphate groups of caseins seem not to be relevant in this interaction because dephosphorylated alpha- and ß-caseins were equally precipitated with chitosans. Analysis by optical microscopy of the chitosan-casein complex reveals that the size of the aggregates increase as the molecular weight of chitosans increase. Hydrophobic and electrostatic interactions particpate in the association and coagulation of casein micelles with chitosans of different molecular weights. The phenomenon is observed over a broad range of temperature (4 to 70°C) with a reduction in the concentration of chitosan needed to precipitate the caseins that parallels a reduction in the viscosity of the chitosan solutions. Taken together, the results indicate that the electrostatic interactions may contribute energetically to the association between the two biopolymers, but the hydrophobicity of the complex would be the key determinant in the overall energetics of the reaction.

Key Words: casein • chitosan • hydrocolloids • casein-chitosan complex

Submitted on May 15, 2000
Accepted on October 12, 2000




This article has been cited by other articles:


Home page
 J DAIRY SCIHome page
E. Casal, A. Montilla, F. J. Moreno, A. Olano, and N. Corzo
Use of Chitosan for Selective Removal of {beta}-Lactoglobulin from Whey
J Dairy Sci, May 1, 2006; 89(5): 1384 - 1389.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2001 by the American Dairy Science Association ®.