Hostname: page-component-8448b6f56d-dnltx Total loading time: 0 Render date: 2024-04-23T10:23:45.925Z Has data issue: false hasContentIssue false

630. The determination of lactose in milk

Published online by Cambridge University Press:  01 June 2009

F. H. Grimbleby
Affiliation:
Department of Agricultural Chemistry, The University, Reading

Extract

One of the most important stages governing the accuracy of lactose determinations in milk is the preparation of the protein-free serum. Factors influencing the lactose content of the serum are: (1) the complete precipitation of protein, (2) the formation of lactose-protein complexes, and (3) the degree of hydration of the protein coagulum.

Experiments are described which show how these factors are influenced by different clearing agents operating at different pH values. On the basis of the results obtained a reagent containing zinc acetate, phosphotungstic acid and acetic acid is suggested; it reduces to a minimum any errors introduced by the above factors.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1956

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)Block, R. J., Bolling, D., Weiss, K. W. & Zweig, G. (1953). Arch. Biochem. Biophys. 47, 88.Google Scholar
(2)Francis, F. J. & Smith, M. D. (1952). J. Dairy Res. 19, 83.CrossRefGoogle Scholar
(3)Garrison, E. R. (1935). J. Ass. off. agric Chem., Wash., 18, 408.Google Scholar
(4)Gorbach, G. & Schafer, P. (1952). Z. LebensmittUntersuch. 95, 168.Google Scholar
(5)Goulden, J. D. S. (1956). Nature, Lond. 177, 85.Google Scholar
(6)Klotz, I. M. (1952). Modern Trends in Physiology and Biochemistry, pp. 427450. New York: Academic Press Inc.Google Scholar
(7)Lane, J. H. & Eynon, L. (1923). J. Soc. chem. Ind., Lond., 42, 32T.Google Scholar
(8)McDowell, A. K. R. (1941). J. Dairy Res. 12, 131.Google Scholar
(9)Mohammad, A., Fraenkel-Conrat, H. & Olcott, H. S. (1949). Arch. Biochem. 24, 157.Google Scholar
(10)Scheibler, C. (1875). Z. Ver. dtsch. Zuckerind. 25, 1054.Google Scholar
(11)Methods of Analysis of the Association of Official Agricultural Chemists (1950). A.O.A.C., Washington, p. 232.Google Scholar