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Reformation of casein particles from alkaline-disrupted casein micelles

Published online by Cambridge University Press:  29 January 2008

Thom Huppertz*
Affiliation:
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland
Betsy Vaia
Affiliation:
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland Hochschule Wadenswil, Wadenswil, Switzerland
Mary A Smiddy
Affiliation:
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland
*
*For correspondence; e-mail: thom.huppertz@nizo.nl

Abstract

In this study, the properties of casein particles reformed from alkaline disrupted casein micelles were studied. For this purpose, micelles were disrupted completely by increasing milk pH to 10·0, and subsequently reformed by decreasing milk pH to 6·6. Reformed casein particles were smaller than native micelles and had a slightly lower zeta-potential. Levels of ionic and serum calcium, as well as rennet coagulation time did not differ between milk containing native micelles or reformed casein particles. Ethanol stability and heat stability, >pH 7·0, were lower for reformed casein particles than native micelles. Differences in heat stability, ethanol stability and zeta-potential can be explained in terms of the influence of increased concentrations of sodium and chloride ions in milk containing reformed casein particles. Hence, these results indicate that, if performed in a controlled manner, casein particles with properties closely similar to those of native micelles can be reformed from alkaline disrupted casein micelles.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 2008

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References

De Kruif, CG & Holt, C 2003 Casein micelle structure, functions and interactions. In Fox, PF, McSweeney, PLH Eds.: Advanced Dairy Chemistry, Vol. 1: Proteins, 3rd edn. pp. 233276. Kluwer Academic/Plenum Publishers, New York, NYGoogle Scholar
Dalgleish, DG 1984 Measurement of electrophoretic mobilities and zeta-potentials of particles from milk using laser Doppler electrophoresis. Journal of Dairy Research 54 425438CrossRefGoogle Scholar
Holt, C 1998 Casein micelle substructure and calcium phosphate interactions studied by sephacryl column chromatography. Journal of Dairy Science 81 29943003CrossRefGoogle Scholar
Holt, C 2004 An equilibrium thermodynamic model of the sequestration of calcium phosphate by casein micelles and its application to the partition of salts in milk. European Biophysics Journal 33 421434CrossRefGoogle Scholar
Holt, C, De Kruif, CG, Tuinier, R & Timmins, PA 2003 Substructure of bovine casein micelles by small-angle X-ray and neutron scattering. Colloids and Surfaces A 213 275284CrossRefGoogle Scholar
Horne, DS & Parker, TG 1983 Factors affecting the ethanol stability of bovine skim-milk. VI. Effect of concentration. Journal of Dairy Research 50 425432CrossRefGoogle Scholar
Huppertz, T & Fox, PF 2006 Effect of NaCl on some physico-chemical properties of bovine milk. International Dairy Journal 16 11421148CrossRefGoogle Scholar
Huppertz, T, Grosman, S, Fox, PF & Kelly, AL 2004 Heat and ethanol stabilities of high pressure-treated bovine milk. International Dairy Journal 14 125133CrossRefGoogle Scholar
Huppertz, T, Smiddy, MA & De Kruif, CG 2007 Biocompatible micro-gelparticles from cross-linked casein micelles. Biomacromolecules 8 13001305CrossRefGoogle ScholarPubMed
McGann, TCA & Fox, PF 1974 Physico-chemical properties of casein micelles reformed from urea-treated milk. Journal of Dairy Research 41 4553CrossRefGoogle Scholar
O'Connell, JE, Kelly, AL, Auty, MAE, Fox, PF & De Kruif, KG 2001a Ethanol-dependent heat-induced dissociation of casein micelles. Journal of Agricultural and Food Chemistry 49 44204423CrossRefGoogle ScholarPubMed
O'Connell, JE, Kelly, AL, Fox, PF & De Kruif, KG 2001b Mechanism for ethanol-dependent heat-induced dissociation of casein micelles. Journal of Agricultural and Food Chemistry 49 44244428CrossRefGoogle ScholarPubMed
O'Connell, JE, Steinle, S, Reiter, F, Auty, MAE, Kelly, AL & Fox, PF 2003 Properties of casein micelles reformed from heated mixtures of milk and ethanol. Colloids and Surfaces A 213 265273CrossRefGoogle Scholar
Semo, E, Kesselman, E, Danino, D & Livney, YD 2007 Casein micelle as a natural nano-capsular vehicle for nutraceuticals. Food Hydrocolloids 21 936942CrossRefGoogle Scholar
Van Dijk, HJM 1992 The properties of casein micelles. 6. Behaviour above pH 9, and implications for the micelle model. Netherlands Milk and Dairy Journal 46 101113Google Scholar
Vaia, B, Smiddy, MA, Kelly, AL & Huppertz, T 2006 Solvent-mediated disruption of casein micelles at alkaline pH. Journal of Agricultural and Food Chemistry 54 82888293CrossRefGoogle ScholarPubMed
Zobrist, MR, Huppertz, T, Uniacke, T, Fox, PF & Kelly, AL 2005 High-pressure-induced changes in the rennet coagulation properties of bovine milk. International Dairy Journal 15 655662CrossRefGoogle Scholar