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Electroacoustic determination of size and zeta potential of casein micelles in skim milk

Published online by Cambridge University Press:  01 June 2009

Theresa Wade
Affiliation:
School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
James K. Beattie
Affiliation:
School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
William N. Rowlands
Affiliation:
School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
Mary-Ann Augustin
Affiliation:
CSIRO Division of Food Science and Technology, Melbourne Laboratory, Highett, VIC 3190, Australia

Summary

Measurements of the zeta potential and particle size of casein micelles in skim milk suspensions at natural and lower pH have been made using the technique of electroacoustics. This technique requires no dilution or change of environment of the casein micelles. The zeta potential obtained at natural pH for a commercial skim milk suspension was −18 mV; it became less negative with decreasing pH. The median particle size observed at natural pH for a commercial skim milk suspension was 0·2 εm, in good agreement with previously reported values. The particle size increased as the pH was decreased.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1996

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References

REFERENCES

Banon, S. & Hardy, J. 1991 Study of acid milk coagulation by an optical method using light reflection. Journal of Dairy Research 58 7584CrossRefGoogle Scholar
Banon, S. & Hardy, J. 1992 A colloidal approach of milk acidification by glucono-delta-lactone. Journal of Dairy Science 75 935941CrossRefGoogle Scholar
Bloomfield, V. A. & Morr, C. V. 1973 Structure of casein micelles: physical methods. Netherlands Milk and Dairy Journal 27 103120Google Scholar
Brings, N. A. & Kinsella, J. E. 1990 Acidic coagulation of casein micelles: mechanisms inferred from spectrophotometric studies. Journal of Dairy Research 57 365375CrossRefGoogle Scholar
Carroll, R. J., Thompson, M. P. & Nutting, G. C. 1968 Glutaraldehyde fixation of casein micelles for electron microscopy. Journal of Dairy Science 51 19031908CrossRefGoogle Scholar
Dalgleish, D. G. 1984 Measurement of electrophoretic mobilities and zeta-potentials of particles from milk using laser Doppler electrophoresis. Journal of Dairy Research 51 425438CrossRefGoogle Scholar
Dalgleish, D. G. & Law, A. J. R. 1988 pH-Induced dissociation of bovine casein micelles. I. Analysis of liberated caseins. Journal of Dairy Research 55 529538CrossRefGoogle Scholar
Dalgleish, D. G. & Law, A. J. R. 1989 pH-Induced dissociation of bovine casein micelles II. Mineral solubilization and its relation to casein release. Journal of Dairy Research 56 727735CrossRefGoogle Scholar
Dalgleish, D. G., Pouliot, Y. & Paquin, P. 1987 Studies on the heat stability of milk II. Association and dissociation of particles and the effect of added urea. Journal of Dairy Research 54 3949CrossRefGoogle Scholar
Darling, D. F. & Dickson, J. 1979 The determination of the zeta potential of casein micelles. Journal of Dairy Research 46 329332CrossRefGoogle Scholar
Davies, D. T. & Law, A. J. R. 1983 Variation in the protein composition of bovine casein micelles and serum casein in relation to mieellar size and milk temperature. Journal of Dairy Research 50 6775CrossRefGoogle Scholar
Dewan, R. K., Chudgar, A., Mead, R., Bloomfield, V. A. & Morr, C. V. 1974 Molecular weight and size distribution of bovine milk casein micelles. Biochimica et Biophysica Acta 342 313321CrossRefGoogle ScholarPubMed
Donnelly, W. J., McNeill, G. P., Buchheim, W. & McGann, T. C. A. 1984 A comprehensive study of the relationship between size and protein composition in natural bovine casein micelles. Biochimica et Biophysica Acta 789 136143CrossRefGoogle ScholarPubMed
Ekstrand, B., & Larsson-Raznikiewicz, M. 1984 Free zone electrophoresis of caseins and casein micelles. Acta Chemica Scandinavica B38 351357CrossRefGoogle Scholar
Fox, P. F. & Nash, B. M. 1979 Physico-chemical characteristics of casein micelles in dilute aqueous media. Journal of Dairy Research 46 357363CrossRefGoogle Scholar
Green, M. L. & Crutchfield, G. 1971 Density-gradient electrophoresis of native and of rennet-treated casein micelles. Journal of Dairy Research 38 151164CrossRefGoogle Scholar
Griffin, M. C. A. & Anderson, M. 1983 The determination of casein micelle size distribution in skim milk by chromatography and photon correlation spectroscopy. Biochimica et Biophysica Acta 748 453459CrossRefGoogle Scholar
Griffin, W. G. & Griffin, M. C. A. 1990 The attenuation of ultrasound in aqueous suspensions of casein micelles from bovine milk. Journal of the Acoustical Society of America 87 25412550CrossRefGoogle Scholar
Heertje, I., Visser, J. & Smits, P. 1985 Structure formation in acid milk gels. Food Microstucture 4 267277Google Scholar
Holt, C. & Dalgleish, D. G. 1986 Eleetrophoretic and hydrodynamic properties of bovine casein micelles interpreted in terms of particles with an outer hairy layer. Journal of Colloid and Interface Science 114 513524CrossRefGoogle Scholar
Holt, C., Dalgleish, D. G. & Parker, T. G. 1973 Particle size distributions in skim milk. Biochimica et Biophysica Acta 328 428432CrossRefGoogle Scholar
Holt, C., Parker, T. G. & Dalgleish, D. G. 1975 Measurement of particle sizes by elastic and quasi-elastic light scattering. Biochimica et Biophysica Acta 400 283292CrossRefGoogle ScholarPubMed
Horne, D. S. 1984 a Determination of the size distribution of bovine casein micelles using photon correlation spectroscopy. Journal of Colloid and Interface Science 98 537548Google Scholar
Horne, D. S. 1984 b Steric effects in the coagulation of casein micelles by ethanol. Biopolymers 23 989993CrossRefGoogle ScholarPubMed
Horne, D. S. 1986 Steric stabilization and casein micelle stability. Journal of Colloid and Interface Science 111 250260Google Scholar
Hunter, R. J. 1986 Foundations of Colloid Science, vol. 1, p. 557. New York: Oxford University Press.Google Scholar
Lin, S. H. C., Dewan, R. K., Bloomfield, V. A. & Morr, C. V. 1971 Inelastic light-scattering study of the size distribution of bovine milk casein micelles. Biochemistry 10 47884793CrossRefGoogle ScholarPubMed
Lucey, J. A. 1992 Acid-base Buffering and Rennet Coagulation Properties of Milk Systems. Thesis, University College, CorkGoogle Scholar
Mulder, H. & Walstra, P. 1974 The Milk Fat Globule: emulsion science as applied to milk products and comparable foods, p. 18. Farnham Royal: Commonwealth Agricultural BureauxGoogle Scholar
O'Brien, R. W. 1988 Electro-acoustic effects in a dilute suspension of spherical particles. Journal of Fluid Mechanics 190 7186Google Scholar
O'Brien, R. W. 1990 The electroacoustic equations for a colloidal suspension. Journal of Fluid Mechanics 212 8193CrossRefGoogle Scholar
O'Brien, R. W., Cannon, D. W. & Rowlands, W. N. 1995 Electroacoustic determination of particle size and zeta potential. Journal of Colloid and Interface Science 173 406418CrossRefGoogle Scholar
O'Brien, R. W., Garside, P. & Hunter, R. J. 1994 The electroacoustic reciprocal relation. Langmuir 10 931935CrossRefGoogle Scholar
Payens, T. A. J. 1966 Association of caseins and their possible relation to structure of the casein micelle. Journal of Dairy Science 49 13171324CrossRefGoogle ScholarPubMed
Pearce, K. N. 1976 Moving boundary electrophoresis of native and rennet-treated casein micelles. Journal of Dairy Research 43 2736CrossRefGoogle Scholar
Roefs, S. P. F. M., Walstra, P., Dalgleish, D. G. & Horne, D. S. 1985 Preliminary note on the change in casein micelles caused by acidification. Netherlands Milk and Dairy Journal 39 119122Google Scholar
Rose, D. 1968 Relation between micellar and serum casein in bovine milk. Journal of Dairy Science 51 18971902Google Scholar
Schmidt, D. G. & Poll, J. K. 1986 Electrokinetic measurements on unheated and heated casein micelle systems. Netherlands Milk and Dairy Journal 40 269280Google Scholar
Van Hooydonk, A. C. M., Hagedoorn, H. G. & Boerrigter, I. J. 1986 pH-induccd physico-chemical changes of casein micelles in milk and their effect on renneting. 1. Effect of acidification on physico-chemical properties. Netherlands Milk and Dairy Journal 40 281296Google Scholar
Vreeman, H. J., Van Markwijk, B. W. & Both, P. 1989 The structure of casein micelles between pH 5·5 and 6·7 as determined by light-scattering, electron microscopy and voluminosity experiments. Journal of Dairy Research 56 463470Google Scholar
Vreeman, H. J., Van Markwijk, B. W. & Both, P. 1991 Size distribution and average size parameters of casein micelles determined by electron microscopy in bovine milk between pH 5·5 and 6·7. A comparison of several evaluation methods. Journal of Dairy Research 58 299312Google Scholar
Walstra, P. 1979 The voluminosity of bovine casein micelles and some of its implications. Journal of Dairy Research 46 317323CrossRefGoogle ScholarPubMed
Walstra, P. 1990 On the stability of casein micelles. Journal of Dairy Science 73 19651979CrossRefGoogle Scholar
Walstra, P., Bloomfield, V. A., Wei, G. J. & Jenness, R. 1981 Effect of chymosin action on the hydrodynamic diameter of casein micelles. Biochimica et Biophysica Acta 669 258259CrossRefGoogle ScholarPubMed
Wilson, J. M., Newcombe, R. J., Denaro, A. R. & Rickett, R. M. W. 1968 Experiments in Physical Chemistry, pp. 89. Oxford: Pergamon PressCrossRefGoogle Scholar