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241. Kay and Graham's phosphatase test: (a) Modifications in technique (b) Effect of bacterial growth

Published online by Cambridge University Press:  01 June 2009

F. K. Neave
Affiliation:
National Institute for Research in Dairying, University of Reading

Extract

1. By the use of sodium hexametaphosphate it is possible to eliminate the final filtration in the phosphatase test, and thus appreciably to shorten the time required for the test.

2. It is necessary to avoid direct sunlight during that part of the test in which Folin's reagent is in use. Other minor precautions are mentioned in the paper.

3. The pH. of the milk samples tested was found to vary naturally before pasteurization from pH 6·5 to 6·9 without affecting the validity of the test.

4. The test is also unaffected by the presence in milk of bacteria which produce reducing substances or which hydrolyse the substrate (sodium phenyl phosphate) unless the organisms are present in very large numbers.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1939

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References

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