Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-20T05:31:58.320Z Has data issue: false hasContentIssue false

Physico-chemical properties of casein micelles reformed from urea-treated milk

Published online by Cambridge University Press:  01 June 2009

T. C. A. McGann
Affiliation:
National Dairy Research Centre, The Agricultural Institute, Fermoy, Co. Cork, Irish Republic
P. F. Fox
Affiliation:
Department of Dairy and Food Chemistry, University College, Cork, Irish Republic

Summary

Micelles reconstituted from urea-treated milk by exhaustive dialysis against bulk milk were similar to native micelles with respect to colloidal phosphate: casein ratio, ethanol stability, heat stability and susceptibility to first-stage rennin action. Reconstituted micelles were considerably smaller than native micelles as indicated by turbidity, sedimentation and viscosity, had shorter second-stage rennet coagulation times, were unstable to [Ca2+] > 20 mM and had reduced base-binding capacity. It is suggested that the induced Ca sensitivity is due to unfavourable alterations in the micellar κ-casein coat arising from the decrease in average micelle size and can be offset by increasing the κ-casein complement of the system or by increasing the degree of aggregation by slowly raising the [Ca2+] level.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 1974

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

Beeby, R. & Kumetat, K. (1959). Journal of Dairy Research 26, 248.CrossRefGoogle Scholar
Berridge, N. J. (1942). Nature 149, 194.CrossRefGoogle Scholar
Davies, D. T. & White, J. C. D. (1958). Journal of Dairy Research 25, 256.CrossRefGoogle Scholar
Downey, W. K. & Murphy, R. F. (1970). Journal of Dairy Research 37, 361.CrossRefGoogle Scholar
Fiske, C. H. & Subbarow, Y. (1925). Journal of Biological Chemistry 66, 375.CrossRefGoogle Scholar
Hill, R. D. & Cracker, B. A. (1968). Journal of Dairy Research 35, 13.CrossRefGoogle Scholar
Hipp, N. J., Groves, M. L., Custer, J. H. & McMeekin, T. L. (1952). Journal of Dairy Science 35, 272.CrossRefGoogle Scholar
Kim, Y. K., Yaguchi, M. & Rose, D. (1969). Journal of Dairy Science 52, 316.CrossRefGoogle Scholar
McGann, T. C. A. & Pyne, G. T. (1960). Journal of Dairy Research 27, 403.CrossRefGoogle Scholar
Manson, W. (1962). Biochimica et Biophysica Acta 63, 515.CrossRefGoogle Scholar
Morr, C. V. (1967). Journal of Dairy Science 50, 1744.CrossRefGoogle Scholar
Pyne, G. T. (1951). Chemistry and Industry, p. 171.Google 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. & Colvin, J. R. (1966). Journal of Dairy Science 49, 351.CrossRefGoogle Scholar
ter Horst, M. G. (1947). Netherlands Milk and Dairy Journal 1, 137.Google Scholar
ter Horst, M. G. (1963). Netherlands Milk and Dairy Journal 17, 185.Google Scholar
Udy, D. C. (1956). Nature 178, 314.CrossRefGoogle Scholar
Wake, R. G. & Baldwin, R. L. (1961). Biochimica et Biophysica Acta 47, 225.CrossRefGoogle Scholar
Warren, L. (1950). Journal of Biological Chemistry 234, 1971.CrossRefGoogle Scholar
White, J. C. D. & Davies, D. T. (1958). Journal of Dairy Research 25, 236.CrossRefGoogle Scholar
Zittle, C. A. & Custer, J. H. (1963). Journal of Dairy Science 46, 1183.CrossRefGoogle Scholar