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Studies on micellar calcium phosphate: composition and apparent solubility product in milk over a wide pH range

Published online by Cambridge University Press:  01 June 2009

Lesley C. Chaplin
Affiliation:
*National Institute for Research in Dairying, (University of Reading), Shinfield, Reading RG2 9 AT, UK

Summary

Calcium and phosphate concentrations in milk ultrafiltrate prepared at 37 °C over the pH range 4.0–8.0 have been measured and used to calculate the apparent solubility products for various calcium phosphates in milk. Micellar calcium phosphate had a constant Ca/Pi = 1·58·10·03 at all pH values and a near-invariant ion activity product for CaHP04. Apparent solubility products have also been obtained for brushite, hydroxyapatite and amorphous tricalcium phosphate in milk salt solution over a similar pH range. No evidence was found for a hydroxyapatite or amorphous tricalcium phosphate phase in milk.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1984

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References

REFERENCES

Gitelman, H. J. 1967 An improved automated procedure for the determination of calcium in biological specimens. Analytical Biochemistry 18 521531CrossRefGoogle Scholar
Holt, C. 1982 Inorganic constituents of milk. III. The colloidal calcium phosphate of cow's milk. Journal of Dairy Research 49 2938CrossRefGoogle ScholarPubMed
Holt, C., Hasnain, S. S.&Hukins, D. W. L. 1982 Structure of bovine milk calcium phosphate determined by X-ray absorption spectroscopy. Biochimica et Biophysica Acta 719 299303CrossRefGoogle ScholarPubMed
Jenness, R. & Koops, J. 1962 Preparation and properties of a salt solution which simulates milk ultrafiltrate. Netherlands Milk and Dairy Journal 16 153164Google Scholar
Lundager Madsen, H. E. 1970 Ionic concentrations in calcium phosphate solutions. I. Solutions saturated with respect to brushite or tetracalcium monohydrogen phosphate at 37 °C. Acta Chemica Scandinavica 24 16711676CrossRefGoogle Scholar
Lyster, R. L. J. 1976 Calorimetric characterization of the micellar calcium phosphate in cow's milk. Biochemical Society Transactions 4 735737CrossRefGoogle Scholar
Lyster, R. L. J. 1981 Calculation by computer of individual concentrations in a simulated milk salt solution. II. An extension to the previous model. Journal of Dairy Research 48 8589CrossRefGoogle Scholar
Posner, A. S. & Betts, F. 1975 Synthetic amorphous calcium phosphate and its relation to bone mineral structure. Accounts of Chemical Research 8 273281CrossRefGoogle Scholar
Rabatin, J. G., Gale, R. H. & Newkirk, A. E. 1960 The mechanism and kinetics of the dehydration of calcium hydrogen phosphate dihydrate. Journal of Physical Chemistry 64 491493CrossRefGoogle Scholar
Schmidt, D. G. 1982 In Developments in Dairy Chemistry -1 Proteins pp. 6186 (Ed. Fox, P. F.) London: Applied Science PublishersGoogle Scholar
Simonsen, D. G., Wertman, M., Westover, L. M. & Mehl, J. W. 1946 The determination of serum phosphate by the molybdivanadate method. Journal of Biological Chemistry 166 747755CrossRefGoogle ScholarPubMed
Spencer, M. 1978 Hydroxyapatite for chromatography. II. Sources of variability and improved methods of preparation. Journal of Chromatography 166 435446CrossRefGoogle Scholar