Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-05-26T14:35:15.862Z Has data issue: false hasContentIssue false

Chemical composition and coagulating properties of renneted Friesian milk during the transition from winter rations to spring grazing

Published online by Cambridge University Press:  01 June 2009

Alistair S. Grandison
Affiliation:
*National Institute for Research in Dairying, (University of Reading), Shinfield, Reading RG2 9At, UK
Graeme D. Ford
Affiliation:
*National Institute for Research in Dairying, (University of Reading), Shinfield, Reading RG2 9At, UK
A. Jane Owen
Affiliation:
*National Institute for Research in Dairying, (University of Reading), Shinfield, Reading RG2 9At, UK
David Millard
Affiliation:
*National Institute for Research in Dairying, (University of Reading), Shinfield, Reading RG2 9At, UK

Summary

The chemical composition and rennet coagulation properties at pH 6·4 of milks from 2 commercial herds of Friesian cows were monitored during the change from winter diet to spring grazing. There was considerable variation both in composition and in coagulation properties during this period. There were significant trends for increasing concentrations of casein, Na and lactose, and decreasing concentrations of fat, citrate, K and Mg following the change. Many correlations occurred between concentrations of components, some of which may have physiological significance. Coagulum strength increased after the change to spring grazing and was related to the concentrations of casein, citrate and some of the minerals. Syneresis time did not follow any trend during this period, but was significantly related to concentrations of fat, Na and K. Rennet clotting time did not follow a significant trend immediately after the dietary change, but tended to increase as the summer progressed; it was significantly related to concentrations of Ca, Pi Na and K, as well as to the original pH of the milk. When the concentration of lactose in milk was adjusted, variations in lactose concentration did not affect the coagulation properties of milk.

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

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

Carić, M. 1978 Proteolytic coagulation of casein in model systems with different ions concentrations. International Congress of Food Science and Technology V Abstracts p. 175 (Dairy Science Abstracts 41 383)Google Scholar
Chapman, H. R. & Burnett, J. 1972 Seasonal changes in the physical properties of milk for cheesemaking. Dairy Industries 37 207211Google Scholar
Clapperton, J. L., Banks, W. & Rook, J. A. F. 1980 Dietary manipulation of the composition of milk. Proceedings of the Nutrition Society 39 64AGoogle Scholar
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 8390CrossRefGoogle Scholar
Hall, A. J. 1970 Seasonal and regional variations in the fatty acid composition of milk fat. Dairy Industries 35 2024Google Scholar
Harding, F. & Royal, L. 1974 Variations in the nitrogen-containing fractions of bulked milk in England and Wales during the period 1947 to 1970. Dairy Industries 39 372378Google Scholar
Journet, M. & Rémond, B. 1980 [Influence of feeding and season on the nitrogenous fractions in cows′milk.] Lait 60 140159CrossRefGoogle Scholar
Keogh, M. K., Kelly, P. M., O'keeffe, A. M. & Phelan, J. A. 1982 Studies of milk composition and its relationship to some processing criteria. II. Seasonal variation in the mineral levels of milk. Irish Journal of Food Science and Technology 6 1327Google Scholar
Konar, A., Thomas, P. C. & Rook, J. A. F. 1971 The concentrations of some water-soluble constituents in the milks of cows, sows, ewes and goats. Journal of Dairy Research 38 333341CrossRefGoogle Scholar
Marshall, R. J. 1982 An improved method for measurement of the syneresis of curd formed by rennet action on milk. Journal of Dairy Research 49 329336CrossRefGoogle Scholar
O'keeffe, A. M., Phelan, J. A., Keogh, K. & Kelly, P. 1982 Studies of milk composition and its relationship to some processing criteria. IV. Factors influencing the renneting properties of a seasonal milk supply. Irish Journal of Food Science and Technology 6 3947Google Scholar
Phelan, J. A., O'keeffe, A. M., Keogh, M. K. & Kelly, P. M. 1982 Studies of milk composition and its relationship to some processing criteria. I. Seasonal changes in the composition of Irish milk. Irish Journal of Food Science and Technology 6 111Google Scholar
Rogers, G. L. & Stewart, J. A. 1982 The effects of some nutritional and non-nutritional factors on milk protein concentration and yield. Australian Journal of Dairy Technology 37 2632Google Scholar
Shalabi, S. I. & Fox, P. F. 1982 Influence of pH on the rennet coagulation of milk. Journal of Dairy Research 49 153157CrossRefGoogle Scholar
Storry, J. E. & Ford, G. D. 1982 a Development of coagulum firmness in renneted milk – atwo-phase process. Journal of Dairy Research 49 343346CrossRefGoogle Scholar
Storry, J. E. & Ford, G. D. 1982 b Some factors affecting the post clotting development of coagulum strength in renneted milk. Journal of Dairy Research 49 469477CrossRefGoogle Scholar
Storry, J. E., Grandison, A. S., Millard, D., Owen, A. J. & Ford, G. D. 1983 The chemical composition and coagulating properties of renneted milks from different breeds and species of ruminant. Journal of Dairy Research 50 215229CrossRefGoogle Scholar
Zienkiewioz-Skulmowska, T., Michalakowa, W., Michalak, W., Siuda, H., Jasiniska, L. & Goszczyński, J. 1978 [Relationships between flocculation time and some properties and components of cows' milk during winter and summer feeding.] Prace i Materialy Zootechniczne No. 16 pp. 8597Google Scholar