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Inorganic constituents of milk III. The colloidal calcium phosphate of cow's milk

  • Carl Holt (a1)


Experiments involving the depletion of milk calcium phosphate (MCP) with EDTA have shown that it has a Ca to phosphate ratio of 1·61±0·04, close to that of dental enamel. The calcium phosphate also contains small amounts of citrate (citrate/Pi = 0·097±0·011) and Mg (Mg/Pi = 0·044 ± 0·011). These experiments and model calculations indicate that the Ca binding capacity of casein is not reduced by mineralization with calcium phosphate and hence that ion binding sites and nucleation sites are distinct, or nearly so. Calculations of the ionic equilibria in the aqueous phase of milk show that there is an invariant ion activity product for a molecular formula close to that of dicalcium phosphate. It is suggested that MCP is a mixture of salts, with dicalcium phosphate a precursor of more basic salts such as octacalcium phosphate and hydroxyapatite.



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Brown, W. E. 1979 General comment. Journal of Dental Research (Special Issue B) 58 857860
Brown, W. E., Smith, J. P., Lehr, J. R. & Frazier, A. W. 1962 Crystallographic and chemical relations between octacalcium phosphate and hydroxyapatite. Nature 196 10501055
Boulet, M. & Marier, J. R. 1961 Precipitation of calcium phosphates from solutions at near physiological concentrations. Archives of Biochemistry and Biophysics 93 157165
Boulet, M., Marier, J. R. & Rose, D. 1962 Effect of magnesium on formation of calcium phosphate precipitates. Archives of Biochemistry and Biophysics 96 629636
Davies, D. T. & Law, A. J. R. 1980 The content and composition of protein in creamery milks in south-west Scotland. Journal of Dairy Research 47 8390
Dickson, I. R. & Perkins, D. J. 1971 Studies on the interactions between purified bovine caseins and alkaline-earth-metal ions. Biochemical Journal 124 235240
Eanes, E. D. 1979 Enamel apatite: chemistry structure and properties. Journal of Dental Research Special Issue B 58 829834
Eanes, E. D. & Meyer, J. L. 1977 The maturation of crystalline calcium phosphates in aqueous suspensions at physiological pH. Calcified Tissue Research 23 259269
Füredi-Milhöfer, H., Puroarić, B., Brecevnć, L. J. & Pavković, N. 1971 Precipitation of calcium phosphates from electrolyte solutions I. A study of the precipitates in the physiological pH range. Calcified Tissue Research 8 142153
Gregory, T. M., Moreno, E. C. & Brown, W. E. 1970 Solubility of CaHPO4. 2H2O in the system Ca(OH)2-H3PO4-H2O at 5, 15, 25 and 375 °C. Journal of Research of the National Bureau of Standards 74 A 461475
Ho, C. & Waugh, D. F. 1965 Interactions of bovine αs-casein with small ions. Journal of the American Chemical Society 87 110117
Holt, C., Dalgleish, D. G. & Jenness, R. 1981 Calculation of the ion equilibria in milk diffusate and comparison with experiment. Analytical Biochemistry 113 154163
Holt, C. & Muir, D. D. 1978 Natural variations in the average size of bovine casein micelles. II. Milk samples from creamery bulk silos in south west Scotland. Journal of Dairy Research 45 347353
Knoop, A. M., Knoop, E. & Wiechen, A. 1979 a Sub-structure of synthetic casein micelles. Journal of Dairy Research 46 347350
Knoop, A. M., Knoop, E., Frede, E., Precht, D. & Wiechen, A. 1979 b Die submikroskopische Struktur natürlicher und künstlicher Caseinmicellen. Milchwissenschaft 34 129131
Lyster, R. L. J. 1976 Calorimetric characterization of the micellar calcium phosphate in cow's milk. Biochemical Society Transactions 4 735737
McDowell, H., Wallace, B. M. & Brown, W. E. 1969 The solubilities of hydroxyapatite at 5, 15, 25 and 37 °C. International Association for Dental Research. Program and Abstracts of Papers No. 340
McGann, T. C. A. & Pyne, G. T. 1960 The colloidal phosphate of milk. III. Nature of its association with casein. Journal of Dairy Research 27 403417
Meyer, J. L. & Eanes, E. D. 1978 a A thermodynamic analysis of the amorphous to crystalline calcium phosphate transformation. Calcified Tissue Research 25 5968
Meyer, J. L. & Eanes, E. D. 1978b A thermodynamic analysis of the secondary transition in the spontaneous precipitation of calcium phosphate. Calcified Tissue Research 25 209216
Moreno, E. C, Brown, W. E. & Osborn, G. 1960 Stability of dicalcium phosphate dihydrate in aqueous solutions and solubility of octacalcium phosphate. Soil Science Society of America Proceedings 24 99102
Muir, D. D. & Sweetsur, A. W. M. 1977 Effect of urea on the heat coagulation of the caseinate complex in skim-milk. Journal of Dairy Research 44 249257
Pyne, G. T. 1934 The colloidal phosphate of milk. Biochemical Journal 28 940948
Pyne, G. T. & McGann, T. C. A. 1960 The colloidal phosphate of milk II. Influence of citrate. Journal of Dairy Research 27 917
Termine, J. D. & Posner, A. S. 1966 Infrared analysis of rat bone: age dependency of amorphous and crystalline mineral fractions. Science 153 15231525
White, J. C. D. & Davies, D. T. 1958 The relation between the chemical composition of milk and the stability of the caseinate complex I. General introduction, description of samples, methods and chemical composition of samples. Journal of Dairy Research 25 236255

Inorganic constituents of milk III. The colloidal calcium phosphate of cow's milk

  • Carl Holt (a1)


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