Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-12-02T21:38:21.077Z Has data issue: false hasContentIssue false
  • English
  • Français

The denaturation of α-lactalbumin and β-lactoglobulin in heated milk

Published online by Cambridge University Press:  01 June 2009

R. L. J. Lyster
R. L. J. Lyster
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, RG2 9AT
Get access Rights & Permissions [Opens in a new window]

Summary

The rates of denaturation by heat of α-lactalbumin and β-lactoglobulin in skim-milk were measured by an immunodiffusion method over a wide range of temperatures. Both reactions showed an unusual temperature dependence.

The denaturation of α-lactalbumin is a first-order reaction; between 90 and 155 °C the kinetic constant k1 in s−1 is given by the equation

where T is the temperature in °K.

The denaturation of β-actoglobulin in skim-milk is second order with respect to time, and the kinetic constant k2 in 1g–1 s–1 is given by 2 equations, valid for different temperature ranges. Between 68 and 90 °C,

Between 90 and 135 °C

Results obtained by the immunodiffusion method agreed well with those found by salt fractionation of the milk proteins. The denaturation rates decreased when a specific reagent for sulphydryl groups was added, suggesting that such groups are involved in the denaturation of both proteins.

Type
Original Articles
Information
Journal of Dairy Research , Volume 37 , Issue 2 , June 1970 , pp. 233 - 243
Copyright
Copyright © Proprietors of Journal of Dairy Research 1970

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

Aschaffenburg, R. (1968). J. Dairy Res. 35, 447.CrossRefGoogle Scholar
Aschaffenburg, R. & Drewry, J. (1955). Nature, Lond. 176, 218.CrossRefGoogle Scholar
Aschaffenburg, R. & Drewby, J. (1957). Biochem. J. 65, 237.CrossRefGoogle Scholar
Aschaffenburg, R. & Drewry, J. (1959). 15th Int. Dairy Congr., London 3, 1631.Google Scholar
Burton, H. (1969). Dairy Sci. Abstr. 31, 287.Google Scholar
Chaudry, S. S. & Humbert, E. S. (1968). J. Dairy Sci. 51, 941.Google Scholar
Gell, P. G. H. & Coombs, R. R. A. (Eds) (1963). Clinical Aspects of Immunology. Oxford: Blackwell.Google Scholar
Gough, P. & Jenness, R. (1962). J. Dairy Sci. 45, 1033.CrossRefGoogle Scholar
Haurowitz, F., DiMoia, F. & Tekman, S. (1952). J. Am. chem. Soc. 74, 2265.CrossRefGoogle Scholar
Hutton, J. T. & Patton, S. (1952). J. Dairy Sci. 35, 699.CrossRefGoogle Scholar
Jenness, R. (1958). Abstr. Pap. Am. Chem. Soc. 133, 58c.Google Scholar
Larson, B. L. & Hageman, E. C. (1963). J. Dairy Sci. 46, 14.CrossRefGoogle Scholar
Larson, B. L. & Rolleri, G. D. (1955). J. Dairy Sci. 38, 351.CrossRefGoogle Scholar
Larson, B. L. & Twarog, J. M. (1961). J. Dairy Sci. 44, 1843.CrossRefGoogle Scholar
Luz, A. Q. & Todd, R. H. (1964). Am. J. Dis. Child. 108, 479.CrossRefGoogle Scholar
Lyster, R. L. J. (1964 a). J. Dairy Res. 31, 41.CrossRefGoogle Scholar
Lyster, R. L. J. (1964 b). Int. Congr. Biochem. 6, New York, Abstracts, 2, 167.Google Scholar
Pantaloni, D. (1964). C. r. hebd. Séanc. Acad. Sci. Paris 259, 1775.Google Scholar
Preer, J. R. Jr & Telfer, W. H. (1957). J. Immun. 79, 288.CrossRefGoogle Scholar
Sawyer, W. H. (1968). J. Dairy Sci. 51, 323.CrossRefGoogle Scholar
Zittle, C. A., Thompson, M. P., Custer, J. H. & Cerbulis, J. (1962). J. Dairy Sci. 45, 807.CrossRefGoogle Scholar