Hostname: page-component-77c89778f8-swr86 Total loading time: 0 Render date: 2024-07-16T11:11:06.551Z Has data issue: false hasContentIssue false
  • English
  • Français

501. The effect of storage at different relative humidities on the survival of micro-organisms in milk powder and in pure cultures dried in milk

Published online by Cambridge University Press:  01 June 2009

Constance Higginbottom
Constance Higginbottom
Affiliation:
The Hannah Dairy Research Institute, Kirkhill, Ayr
Get access Rights & Permissions [Opens in a new window]

Extract

1. Two spray-dried milks, one separated and one whole milk, have been stored at 25°C. for 48 and 103 weeks respectively at relative humidities ranging from 0 to 100%. At high humidities (80–100% r.h.) a rapid fall in the numbers of bacteria was followed by rapid growth of bacteria and by overgrowth by moulds. At relative humidities below 80% the number of surviving bacteria increased with decreasing humidity to maximum survival at about 10% r.h. and then tended to fall again towards 0% r.h.

2. The changes in the distribution of the different types of bacteria in the dried milks at different relative-humidities are discussed.

3. Maximum survival at 5–15% r.h. has been confirmed with pure cultures (dried in milk) of a Streptococcus and a Micrococcus originally isolated from dried milks.

4. The marked loss of viability of bacterial spores noted in dried milks stored over P2O5 or concentrated H2SO4 has been confirmed for a dried suspension of the spores of a typical strain of Bacillus subtilis.

Type
Original Articles
Information
Journal of Dairy Research , Volume 20 , Issue 1 , February 1953 , pp. 65 - 75
Copyright
Copyright © Proprietors of Journal of Dairy Research 1953

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

(1)Higginbottom, C. (1944). J. Dairy Res. 13, 324.Google Scholar
(2)Higginbottom, C. (1948). Proc. Soc. appl. Bact. p. 18.Google Scholar
(3)Watts, P. S. (1945). J. Path. Bact. 57, 191.CrossRefGoogle Scholar
(4)Wilson, R. E. (1921). J. industr. Engng Chem. 8, 326.CrossRefGoogle Scholar
(5)Snow, D., Crichton, M. H. G. & Wright, N. C. (1944). Ann. appl. Biol. 31, 111.CrossRefGoogle Scholar
(6)Van Dam, J. & Warffemius, G. G. (1944). Leeuwenhoek ned. Tijdschr. 10, 123.Google Scholar
(7)Snow, D., Crichton, M. H. G. & Wright, N. C. (1944). Ann. appl. Biol. 31, 102.CrossRefGoogle Scholar
(8)Gibbons, N. E. & Fulton, C. O. (1943). Canad. J. Res. 22D, 332.Google Scholar
(9)Clayton, C. N. (1942). Phytopathology, 32, 921.Google Scholar
(10)Handbook of Chemistry and Physics (1945). 29th ed. p. 1877. Ohio: Chemical Rubber Publishing Co.Google Scholar
(11)Johnson, L. P. V. (1946). Canad. J. Res. 24C, 298.CrossRefGoogle Scholar
(12)Bullock, K. & Lightbown, J. W. (1947). Quart. J. Pharm. 20, 312.Google Scholar