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An automatic method for measuring the heat coagulation time of milk powder solutions

Published online by Cambridge University Press:  01 June 2009

Helmut Foissy  and
Wolfgang Kneifel
Helmut Foissy
Affiliation:
Department of Dairy Research, Agricultural University, Vienna A-1180, Austria
Wolfgang Kneifel
Affiliation:
Department of Dairy Research, Agricultural University, Vienna A-1180, Austria
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Summary

An apparatus for the objective determination of the heat coagulation time of milk powder solutions is described. In the apparatus a chromium plated iron piston is moved by means of a ring magnet, driven by a control mechanism, through a heated cylinder containing a small sample of milk. When the milk coagulates, the increased impedance between the inner wall of the cylinder and the metal piston overcomes the magnetic strength of the ring magnet and the magnetic coil moves away from the piston core, resulting in a momentary change in coil current, which after amplification is used to stop a digital clock. The method was tested with 10 and 20 % milk powder solutions at various pH values, at temperatures of 120 and 140 °C. The results are comparable with those obtained using a traditional method involving visual determination of coagulation (Davies & White, 1966).

Type
Original Articles
Information
Journal of Dairy Research , Volume 51 , Issue 2 , May 1984 , pp. 325 - 329
Copyright
Copyright © Proprietors of Journal of Dairy Research 1984

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References

REFERENCES

Davies, D. T. & White, J. C. D. 1966 The stability of milk protein to heat. I. Subjective measurement of heat stability of milk. Journal of Dairy Research 33 67–81CrossRefGoogle Scholar
Foissy, H. 1982 Austrian patent application no. 3047/82Google Scholar
Fox, P. F. 1982 Heat-induced coagulation of milk. In Developments in dairy chemistry. 1. Proteins, pp. 189–228 (Ed. Fox, P. F.) London: Applied Science PublishersGoogle Scholar
Howat, G. R. & Wright, N. C. 1934 The heat coagulation of caseinogen. I. The role of phosphorus cleavage. Biochemical Journal 28 1336–1345CrossRefGoogle ScholarPubMed
Rose, D. 1961 Variations in the heat stability and composition of milk from individual cows during lactation. Journal of Dairy Science 44 430–441CrossRefGoogle Scholar
Sommer, H. H. & Hart, E. B. 1919 The heat coagulation of milk. Journal of Biological Chemistry 40 137–146CrossRefGoogle Scholar
Standards Association of Australia 1978 Determination of the heat stability of skim milk powder. Australian Standard 1629.3.4. 1978Google Scholar
White, J. C. D. & Davies, D. T. 1966 The stability of milk protein to heat. III. Objective measurement of heat stability of milk. Journal of Dairy Research 33 93–102CrossRefGoogle Scholar
Whitney, R. McL., Paulson, K. & Murthy, G. K. 1952 A test of the heat stability of milk proteins for use in research. Journal of Dairy Science 35 937–948CrossRefGoogle Scholar