Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-06T10:41:07.213Z Has data issue: false hasContentIssue false
  • English
  • Français

Changes on storage in milk processed by ultra-high-temperature sterilization

Published online by Cambridge University Press:  01 June 2009

Ruth Samel ,
R. W. V. Weaver  and
D. B. Gammack
Ruth Samel
Affiliation:
Unigate Central Laboratory, Western Avenue, Acton, London, W. 3
R. W. V. Weaver
Affiliation:
Unigate Central Laboratory, Western Avenue, Acton, London, W. 3
D. B. Gammack
Affiliation:
Unigate Central Laboratory, Western Avenue, Acton, London, W. 3
Get access Rights & Permissions [Opens in a new window]

Summary

Samples of commercially processed ultra-high-temperature (UHT) milk were stored at 4, 20, 30 and 37°C for up to 2 years or until gelation occurred.

The stability of the proteins to ethanol, calcium ions and rennet decreased with time of storage. However, preliminary autoclaving of the UHT milk induced a high degree of stability.

The extent of protein decomposition that had occurred in the UHT milk samples depended on the time and temperature of storage. There was negligible decomposition when the samples had been autoclaved before storage at 4 and 20°C. Storage at 37°C led to significant decomposition.

UHT milk samples gelled after being stored for 13 months at 4, 20 and 30°C, but not at 37°C. The autoclaved milk was still fluid after being stored for 2 years at these temperatures.

The time of onset of gelation did not depend on the degree of protein breakdown, and it seemed therefore that proteolysis was not the primary cause of gelation on storage.

It was concluded that the proteins in UHT milk underwent several changes on storage that were apparently independent of each other and led ultimately to coagulation of the milk. These changes included proteolysis, and a progressive loss of stability under conditions that favoured aggregation of the casein micelles.

Type
Original Articles
Information
Journal of Dairy Research , Volume 38 , Issue 3 , October 1971 , pp. 323 - 332
Copyright
Copyright © Proprietors of Journal of Dairy Research 1971

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

Alfa-Laval, (1967). Br. Pat. 1058030.Google Scholar
Aminoff, D. (1961). Biochem. J. 81, 384.CrossRefGoogle Scholar
Barker, S. A. & Stacey, M. (1963). Dairy Sci. Abstr. 25, 445.Google Scholar
Hill, R. D. (1970). J. Dairy Res. 37, 187.CrossRefGoogle Scholar
Hill, R. D. & Craker, B. A. (1968). J. Dairy Res. 35, 13.CrossRefGoogle Scholar
Hostettler, H., Stein, J. & Bruderer, G. (1957). Landw. Jb. Schweiz 71, 143.Google Scholar
Jenness, R. & Patton, S. (1959). Principles of Dairy Chemistry, p. 340. London: Chapman and Hall, Ltd.Google Scholar
Marier, J. R., Tessier, H. & Rose, D. (1963). J. Dairy Sci. 46, 373.CrossRefGoogle Scholar
Nakai, S., Welson, H. K. & Herreid, E. O. (1964). J. Dairy Sci. 47, 754.CrossRefGoogle Scholar
Rowland, S. J. (1938 a). J. Dairy Res. 9, 42.CrossRefGoogle Scholar
Rowland, S. J. (1938 b). J. Dairy Res. 9, 47.CrossRefGoogle Scholar
Samuelsson, E. G. & Holm, S. (1966). 17th Int. Dairy Congr., Munich B, 57.Google Scholar
Wake, R. G. (1959). Aust. J. biol. Sci. 12, 479.CrossRefGoogle Scholar