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471. The role of micro-organisms in dye-reduction and keeping-quality tests: I. The change in dominant bacterial flora during incubation at 37·5 and 22° C. and the part played by staphylococci and the coli-aerogenes group

Published online by Cambridge University Press:  01 June 2009

Ellen I. Garvie  and
A. Rowlands
Ellen I. Garvie
Affiliation:
National Institute for Research in Dairying, University of Reading
A. Rowlands
Affiliation:
National Institute for Research in Dairying, University of Reading
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Extract

1. The present work was planned to provide an explanation of the lack of correlation for individual samples between the results of dye-reduction tests at 37·5° C. and keeping-quality tests at 22° C. A special study was made of the particular part played by the staphylococci (in thirty-eight samples) and the coli-aerogenes group (in thirty-seven samples) in dye reduction at 37·5° C. and in keeping quality at 22° C. A detailed study was also made of the changes in bacterial flora of twelve samples during incubation at these temperatures.

2. In milk, after overnight storage at 14° C., staphylococci were found to constitute only a small proportion of the bacterial flora, but their numbers increased during incubation at 37·5° C. (for the dye-reduction test) and at 22° C. (for the clot-on-boiling test). At the time of dye reduction staphylococci were found to constitute a major part of the bacterial flora, particularly in samples taking 5 hr. or more to reduce the dye. Although the staphylococci increased in numbers during incubation at 22° C. they constituted only a relatively small proportion of the flora at the time of the end-point of the clot-on-boiling test.

3. Initially the coli-aerogenes group were found to constitute only a small proportion of the total bacterial flora. Some growth usually occurred during incubation at 37·5 and 22° C.

Type
Original Articles
Information
Journal of Dairy Research , Volume 19 , Issue 2 , June 1952 , pp. 133 - 152
Copyright
Copyright © Proprietors of Journal of Dairy Research 1952

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References

REFERENCES

(1)Rowlands, A., Barkworth, H., Hosking, Z. & Kempthorne, O.. (1950). J. Dairy Res. 17, 159.Google Scholar
(2)Wilson, G. S. (1935). Spec. Rep. Ser. med. Res. Coun., Land., no. 206.Google Scholar
(3)Jensen, H. O. (1937). Zbl. Bakt., II. Abt., 96, 110.Google Scholar
(4)Davis, R. N. & Lines, K. W. (1939). J. Dairy Sci. 22, 209.CrossRefGoogle Scholar
(5)Hobbs, B. C. (1939). J. Dairy Res. 10, 35.CrossRefGoogle Scholar
(6)Thomé, K. E. (1941). Medd. Mejeriförsök. 7.Google Scholar
(7)Barkworth, H., Mattick, A. T. R., Taylor, M. G. D. & Williams, R. S. (1927). J. Minist. Agric. 33, 997.Google Scholar
(8)Barkworth, H., Meanwell, L. J. & Taylor, M. G. D. (1929). J. Minist. Agric. 36, 170.Google Scholar
(9)Barkworth, H. (1934). J. Dairy Res. 6, 36.Google Scholar
(10)Malcolm, J. F. (1934). J. Dairy Res. 5, 15.CrossRefGoogle Scholar
(11)Garvie, E. I. & Rowlands, A. (1952). Proc. Soc. appl. Bact. (in the Press).Google Scholar
(12)Ministry of Health (1937). Memo 139/Foods.CrossRefGoogle Scholar
(13)Miles, A. A. & Misra, S. S. (1938). J. Hyg., Camb., 38, 732.Google Scholar
(14)Chapman, G. H. (1946). J. Bact. 51, 409.Google Scholar
(15)Chapman, G. H. (1949). J. Bact. 58, 823.CrossRefGoogle Scholar
(16)Bartram, M. T. & Black, L. A. (1936). Food Res. 1, 551.CrossRefGoogle Scholar
(17)Minett, F. C. (1937). J. comp. Path. 50, 101.CrossRefGoogle Scholar
(18)Shattock, P. M. F. & Mattick, E. C. V. (1940). J. Dairy Res. 11, 311.CrossRefGoogle Scholar
(19)Mattick, A. T. R. & Procter, F. (1928). J. Hyg., Camb., 27, 215.CrossRefGoogle Scholar
(20)Sherman, J. M. & Wino, H. G. (1933). J. Dairy Sci. 16, 165.CrossRefGoogle Scholar
(21)Crossley, E. L. (1946). J. Dairy Res. 14, 233.CrossRefGoogle Scholar
(22)Rowlands, A. (1939). J. Hyg., Camb., 39, 454.Google Scholar
(23)Cunningham, A. & McLeod, D. H. (1948). Proc. Soc. appl. Bact. p. 20.Google Scholar
(24)Ayers, S. H. & Clemmer, P. W. (1918). Bull. U.S. Dep. Agric. no. 739.Google Scholar
(25)Rowlands, A. & Provan, A. L. (1941). Proc. Soc. agric. Bact. p. 29.Google Scholar
(26)Soriano, A. M. De (1946). Rev. Argent. Dietol. 4, 63.Google Scholar
(27)Ashton, T. R. (1950). J. Dairy Res. 17, 261.CrossRefGoogle Scholar
(28)Egdell, J. W. & Bird, E. R. (1950). J. Soc. Dairy Tech. 3, 171.CrossRefGoogle Scholar
(29)Garvie, E. I. & Rowlands, A. (1952). J. Dairy Res. (in the Press).Google Scholar