Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-19T05:04:19.687Z Has data issue: false hasContentIssue false

Casein compositional studies: 1. The composition of casein from Friesian herd milks

Published online by Cambridge University Press:  01 June 2009

J. Gerard Barry
Affiliation:
The Agricultural Institute, Moorepark Research Centre, Fermoy, Co. Cork, Irish Republic
William J. Donnelly
Affiliation:
The Agricultural Institute, Moorepark Research Centre, Fermoy, Co. Cork, Irish Republic

Summary

Casein composition in Friesian herd milks was examined by quantitative column chromatography on hydroxyapatite. Whole casein was resolved into 5 fractions: (1) γ-casein + para-κ-casein; (2) κ-casein + unidentified chymosin-resistant components; (3) unidentified minor protein; (4) β-casein; (5) αs1,0- + minor αs-caseins. Protein in fractions 1, 2, 4, 5 was measured by ultraviolet spectrometry, using appropriate specific absorption coefficients. The quantitative contribution of chymosin-resistant components to the κ-casein fraction was measured by a method involving hydroxyapatite chromatography of chymosin-treated whole casein. Compositional analysis was carried out throughout a lactation cycle on a total of 24 casein samples from the milks of a winter/spring calving and autumn-calving herd. Average composition (expressed as % total casein), which was similar for both herds, was 48·7% αs-, 33·8% β-, 4·9% γ-, 9·5% κ- and 3·2% unidentified components. Lactational effects on composition were also similar for both herds and were most pronounced in late lactation where increases were recorded in γ-casein and unidentified components, and decreases in β- and αs-caseins. Fluctuations in κ-casein proportions were small and slightly higher values were obtained in early and late lactation. Casein composition also appeared to be affected to some extent by season, as shown by differences in the proportions of αs-caseins and unidentified components between mid-lactation milks from the 2 herds. Compositional variations resulted partly from the action of milk proteinase on β-casein and also, apparently, from differences in relative rates of protein biosynthesis.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1980

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

Andrews, A. T. (1978a). European Journal of Biochemistry 90, 5965.CrossRefGoogle Scholar
Andrews, A. T. (1978b). European Journal of Biochemistry 90, 6771.Google Scholar
Atkinson, A., Bradford, P. A. & Selmes, I. P. (1973). Journal of Applied Chemistry and Biotechnology 23, 517530.Google Scholar
Barry, J. G. & Donnelly, W. J. (1979). Biochemical Society Transactions 7, 529531.Google Scholar
Bloomfield, V. A. & Mead, R. J. Jr (1975). Journal of Dairy Science 58, 592601.Google Scholar
Castle, A. V. & Wheelock, J. V. (1971). Journal of Dairy Research 38, 6971.Google Scholar
Davies, D. T. & Law, A. J. R. (1977a). Journal of Dairy Research 44, 213221.Google Scholar
Davies, D. T. & Law, A. J. R. (1977b). Journal of Dairy Research 44, 447454.CrossRefGoogle Scholar
Dill, C. W., McGill, R., Lane, G. T., Bryant, J. N. & Thompson, Y. (1972). Journal of Dairy Science 55, 200203.CrossRefGoogle Scholar
Donnelly, W. J. (1977). Journal of Dairy Research 44, 621625.CrossRefGoogle Scholar
Groves, M. L. & Gordon, W. G. (1969). Biochimica et Biophysica Acta 194, 421432.Google Scholar
Haenlein, G. F. W., Schultz, L. H. & Zikakis, J. P. (1973). Journal of Dairy Science 56, 10171024.CrossRefGoogle Scholar
Hossain, M. A. & Gravert, H. O. (1976). Milchwissenschaft 31, 457461.Google Scholar
Kirchmeier, O. (1970). 8th International Congress of Nutrition, Prague, 1969, pp. 750754.Google Scholar
Mercier, J. C., Maubois, J. L., Poznanski, S. & Ribadeau-Dumas, B. (1968). Bulletin de la Société de Chimie Biologique 50, 521530.Google Scholar
Morr, C. V., Lin, S. H. C. & Josephson, R. V. (1971). Journal of Dairy Science 54, 9941000.CrossRefGoogle Scholar
O'leary, P. A. & Fox, P. F. (1974). Journal of Dairy Research 41, 381387.Google Scholar
Reddi, K. K. (1957). Biochimica et Biophysica Acta 24, 238241.CrossRefGoogle Scholar
Ribadeau Dumas, B. (1968). Biochimica et Biophysica Acta 168, 274281.CrossRefGoogle Scholar
Ribadeau Dumas, B. & Garnier, J. (1970). Journal of Dairy Research 37, 269278.CrossRefGoogle Scholar
Rolleri, G. D., Larson, B. L. & Touchberry, R. W. (1956). Journal of Dairy Science 39, 16831689.CrossRefGoogle Scholar
Rose, D. & Colvin, J. R. (1966). Journal of Dairy Science 49, 10911097.CrossRefGoogle Scholar
Sanderson, W. B. (1970). 18th International Dairy Congress, Sidney, IE, 28.Google Scholar
Sebela, F. & Klicnik, V. (1977). Živočišná Výroba 22, 139146.Google Scholar
Slattery, C. W. (1976). Journal of Dairy Science 59, 15471556.CrossRefGoogle Scholar
Talbot, B. & Waugh, D. F. (1970). Biochemistry 9, 28072813.Google Scholar
Thompson, M. P. & Pepper, L. (1964). Journal of Dairy Science 47, 633637.Google Scholar
Thompson, M. P., Gordon, W. G., Boswell, R. T. & Farrell, H. M. Jr (1969). Journal of Dairy Science 52, 11661173.CrossRefGoogle Scholar
Thymann, M. (1972). Acta Veterinaria Scandinavica 13, 539553.Google Scholar
Wake, R. G. & Baldwin, R. L. (1961). Biochimica et Biophysica Acta 47, 225239.Google Scholar
Waugh, D. F. (1971) in Milk Proteins vol. 2, pp. 385 (Ed. McKenzie., H. A.) New York: Academic Press.Google Scholar
Waugh, D. F., Slattery, C. W. & Creamer, L. K. (1971). Biochemistry 10, 817823.Google Scholar
Woychik, J. H. & Kalan, E. B. (1965). Journal of Dairy Science 48, 11131114.CrossRefGoogle Scholar