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Heat stability of milk: influence of colloidal calcium phosphate and β-lactoglobulin

Published online by Cambridge University Press:  01 June 2009

P. F. Fox  and
M. C. T. Hoynes
P. F. Fox
Affiliation:
Department of Food Chemistry, University College, Cork, Irish Republic
M. C. T. Hoynes
Affiliation:
Department of Food Chemistry, University College, Cork, Irish Republic
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Summary

Reduction of the level of colloidal calcium phosphate (CCP) progressively increased the heat stability of milk at pH values <~7·0 and increased the pH of maximum stability. Removal of 40% CCP also stabilized the system at the pH of minimum stability, but removal of ≥60% CCP rendered milk very unstable at pH values >7·2, an effect not offset by a 4-fold increase in κ-casein concentration. Doubling CCP had a slight destabilizing effect in the pH range 6·5–7·5.

Addition of β-lactoglobulin to serum protein-free casein micelles had a marked destabilizing effect at pH values > ~6·8, but increased stability in the pH range 6·4–6·8. β-Lactoglobulin had a similar and more apparent effect on the heat stability of Na caseinate dissolved in milk diffusate.

It is suggested that rather than being a stabilizing factor responsible for the maximum in the heat stability-pH curve, the true effect of β-lactoglobulin is to shift the curve to more acid pH values (reason unknown) and to sensitize the caseinate system to heat-induced Ca phosphate precipitation at pH values > ~7·0. Low stability at ~pH 7·0 introduces an apparent maximum in the heat stability-pH curve at ~pH 6·8, but this has no independent existence. At pH values >7·2, increased protein charge more than off-sets the influence of heat-precipitated CCP and stability again increases in micellar but not in soluble casein systems.

Type
Research Article
Information
Journal of Dairy Research , Volume 42 , Issue 3 , October 1975 , pp. 427 - 435
Copyright
Copyright © Proprietors of Journal of Dairy Research 1975

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References

REFERENCES

Benton, A. G. & Albery, H. G. (1926). Journal of Biological Chemistry 68, 251.CrossRefGoogle Scholar
Davies, D. T. & White, J. C. D. (1959). 15th International Dairy Congress, London 3, 1677.Google Scholar
Davies, D. T. & White, J. C. D. (1966). Journal of Dairy Research 33, 67.CrossRefGoogle Scholar
Downey, W. K. & Murphy, R. F. (1970). Journal of Dairy Research 37, 361.CrossRefGoogle Scholar
Fiske, C. H. & Subbarrow, Y. (1925). Journal of Biological Chemistry 66, 375.CrossRefGoogle Scholar
Fox, K. K., Holsinger, V. H., Posati, L. P. & Pallansch, M. J. (1967). Journal of Dairy Science 50, 1363.CrossRefGoogle Scholar
McGann, T. C. A. & Pyne, G. T. (1960). Journal of Dairy Research 27, 403.CrossRefGoogle Scholar
Morrissey, P. A. (1969). Journal of Dairy Research 36, 343.CrossRefGoogle Scholar
Pyne, G. T. (1953). 13th International Dairy Congress, The Hague 3, 1032.Google Scholar
Pyne, G. T. (1955). Dairy Science Abstracts 17, 532.Google Scholar
Pyne, G. T. (1958). Journal of Dairy Research 25, 467.CrossRefGoogle Scholar
Pyne, G. T. (1959). 15th International Dairy Congress, London 3, 1673.Google Scholar
Pyne, G. T. (1962). Journal of Dairy Research 29, 101.CrossRefGoogle Scholar
Pyne, G. T. & McGann, T. C. A. (1960). Journal of Dairy Research 27, 9.CrossRefGoogle Scholar
Pyne, G. T. & McHenry, K. A. (1955). Journal of Dairy Research 22, 60.CrossRefGoogle Scholar
Rose, D. (1961 a). Journal of Dairy Science 44, 430.CrossRefGoogle Scholar
Rose, D. (1961 b). Journal of Dairy Science 44, 1405.CrossRefGoogle Scholar
Rose, D. (1962). Journal of Dairy Science 45, 1305.CrossRefGoogle Scholar
Rose, D. (1963). Dairy Science Abstracts 25, 45.Google Scholar
Rose, D. (1965). Journal of Dairy Science 48, 139.CrossRefGoogle Scholar
Sommer, H. H. & Hart, E. B. (1919). Journal of Biological Chemistry 40, 137.CrossRefGoogle Scholar
Sommer, H. H. & Hart, E. B. (1922). Journal of Dairy Science 5, 525.CrossRefGoogle Scholar
Tessier, H. & Rose, D. (1964). Journal of Dairy Science 47, 1047.CrossRefGoogle Scholar
Webb, B. H. & Holm, G. E. (1932). Journal of Dairy Science 15, 345.CrossRefGoogle Scholar
White, J. C. D. & Davies, D. T. (1958). Journal of Dairy Research 25, 281.CrossRefGoogle Scholar
Zittle, C. A. & Custer, J. H. (1963). Journal of Dairy Science 46, 1183.CrossRefGoogle Scholar