Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-22T22:38:48.490Z Has data issue: false hasContentIssue false

Variation in the protein composition of bovine casein micelles and serum casein in relation to micellar size and milk temperature

Published online by Cambridge University Press:  01 June 2009

D. Thomas Davies
Affiliation:
Hannah Research Institute, Ayr, Scotland, KA6 5HL
Andrew J. R. Law
Affiliation:
Hannah Research Institute, Ayr, Scotland, KA6 5HL

Summary

The caseinate complex in bovine milk was partitioned by differential centrifugation at both 20 and 4 °C into 4 micellar fractions and a fraction representing serum casein, and the protein composition of the fractions determined. At both temperatures the relative amount of κ-casein in the micellar caseins increased markedly and that of β-casein decreased appreciably with decreasing micelle size. The relative amount of αs2-casein also tended to decrease with decreasing micelle size, but the relative amounts of αs1- and γ-caseins, and an unidentified casein fraction, showed little systematic variation. The serum casein differed appreciably in composition from the micellar caseins, being very rich in β-casein and comparatively poor in αsl- and αs2-caseins, and the amount present at 4 °C was considerably greater than at 20 °C, with the increase being due almost entirely to β-casein, but with γ-casein also making a significant contribution. The changes in the composition and distribution of micellar and serum caseins induced by cooling milk at 4 °C were completely reversible when the milk was re-equilibrated at 20 °C for 18 h.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Ali, A. E., Andrews, A. T. & Cheeseman, G. C. 1980 Influence of storage of milk on casein distribution between the micellar and soluble phases and its relationship to cheese-making parameters. Journal of Dairy Research 47 371382CrossRefGoogle Scholar
Anderson, M., Brooker, B. E., Andrews, A. T. & Alichanidis, E. 1974 Membrane material isolated from milk of mastitic and normal cows. Journal of Dairy Science, 57 14481458CrossRefGoogle ScholarPubMed
Creamer, L. K., Berry, G. P. & Mills, O. E. 1977 A study of the dissociation of β-casein from the bovine casein micelle at low temperature. New Zealand Journal of Dairy Science and Technology 12 5866Google Scholar
Dalgleish, D. G., Brinkhuis, J. & Payens, T. A. J. 1981 The coagulation of differently sized casein micelles by rennet. European Journal of Biochemistry 119 257261CrossRefGoogle ScholarPubMed
Davies, D. T. & Law, A. J. R. 1977 a An improved method for the quantitative fractionation of casein mixtures using ion-exchange chromatography. Journal of Dairy Research 44 213221CrossRefGoogle Scholar
Davies, D. T. & Law, A. J. R. 1977 b The composition of whole casein from the milk of Ayrshire cows. Journal of Dairy Research 44 447454CrossRefGoogle Scholar
Davies, D. T. & White, J. C. D. 1960 The use of ultrafiltration and dialysis in isolating the aqueous phase of milk and in determining the partition of milk constituents between the aqueous and disperse phases. Journal of Dairy Research 27 171190CrossRefGoogle Scholar
Downey, W. K. 1973 Structure of bovine casein micelles. Netherlands Milk and Dairy Journal 27 218219Google Scholar
Downey, W. K. & Murphy, R. F. 1970 The temperature-dependent dissociation of β-casein from bovine casein micelles and complexes. Journal of Dairy Research 37 361372CrossRefGoogle 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
Lin, S. H. C., Leong, S. L., Dewan, R. K., Bloomfield, V. A. & Morr, C. V. 1972 Effect of calcium ion on the structure of native bovine casein micelles. Biochemistry 11 18181821CrossRefGoogle ScholarPubMed
McGann, T. C. A., Donnelly, W. J., Kearney, R. D. & Buchheim, W. 1980 Composition and size distribution of bovine casein micelles. Biochimica et Biophysica Acta 630 261270CrossRefGoogle ScholarPubMed
McGann, T. C. A., Kearney, R. D. & Donnelly, W. J. 1979 Developments in column chromatography for the separation and characterization of casein micelles. Journal of Dairy Research 46 307311CrossRefGoogle ScholarPubMed
Morr, C. V., Lin, S. H. C. & Josephson, R. V. 1971 Fractionation of skimmilk casein micelles by rate-zone and isopycnie-zone ultracentrifugation in sucrose gradients. Journal of Dairy Science 54 9941000CrossRefGoogle Scholar
Némethy, G. & Scheraga, H. A. 1962 The structure of water and hydrophobic bonding in proteins. III. The thermodynamic properties of hydrophobic bonds in proteins. Journal of Physical Chemistry 66 17731789CrossRefGoogle Scholar
Payens, T. A. J. & Heremans, K. 1969 Effect of pressure on the temperature-dependent association of βcasein. Biopolymers 8 335345CrossRefGoogle ScholarPubMed
Plantz, P. E., Patton, S. & Keenan, T. W. 1973 Further evidence of plasma membrane material in skim milk. Journal of Dairy Science 56 978983CrossRefGoogle ScholarPubMed
Pyne, G. T. 1945 Rennet hysteresis and the calcium phosphate of milk. Biochemical Journal 39 385390CrossRefGoogle Scholar
Reardon, J., Foreman, J. A. & Searcy, R. L. 1966 New reactants for the colorimetric determination of ammonia. Clinica Chimica Acta 14 403405CrossRefGoogle ScholarPubMed
Rose, D. 1968 Relation between micellar and serum casein in bovine milk. Journal of Dairy Science 51 18971902CrossRefGoogle Scholar
Rose, D., Davies, D. T. & Yaguchi, M. 1969 Quantitative determination of the major components of casein mixtures by column chromatography on DEAE-cellulose. Journal of Dairy Science 52 811CrossRefGoogle Scholar
Rowland, S. J. 1938 The determination of the nitrogen distribution in milk. Journal of Dairy Research 9 4246CrossRefGoogle Scholar
Saito, Z. 1973 Electron microscopic and compositional studies of casein micelles. Netherlands Milk and Dairy Journal 27 143162Google Scholar
Scheraga, H. A., Némethy, G. & Steinberg, I. Z. 1962 The contribution of hydrophobic bonds to the thermal stability of protein conformations. Journal of Biological Chemistry 237 25062508CrossRefGoogle Scholar
Schmidt, D. G. & Payens, T. A. J. 1972 The evaluation of positive and negative contributions to the second virial coefficient of some milk proteins. Journal of Colloid and Interface Science 39 655662CrossRefGoogle Scholar
Sharma, K. K. & Randolph, H. E. 1974 Influence of mastitis on properties of milk. VIII. Distribution of soluble and micellar casein. Journal of Dairy Science 57 1923CrossRefGoogle Scholar
Slattery, C. W. 1978 Variation in the glycosylation pattern of bovine κ-casein with micelle size and its relationship to a micelle model. Biochemistry 17 11001104CrossRefGoogle ScholarPubMed
Sullivan, R. A., Fitzpatrick, M. M. & Stanton, E. K. 1959 Distribution of kappa-casein in skim milk. Nature 183 616617CrossRefGoogle ScholarPubMed
Walstra, P. 1980 Effect of homogenization on milk plasma. Netherlands Milk and Dairy Journal 34 181190Google Scholar
Whitaker, R., Sherman, J. M. & Sharp, P. F. 1927 Effect of temperature on the viscosity of skimmilk. Journal of Dairy Science 10 361371CrossRefGoogle Scholar
Yaguchi, M., Davies, D. T. & Kim, Y. K. 1968 Preparation of κ-casein by gel filtration. Journal of Dairy Science 51 473477CrossRefGoogle Scholar