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Effects of adding potassium iodate to milk before UHT treatment: II. Iodate-induced proteolysis during subsequent aseptic storage

Published online by Cambridge University Press:  01 June 2009

Paul J. Skudder
Paul J. Skudder
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, RG2 9 AT
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Summary

The addition of potassium iodate to milk at 0·1 mm before UHT treatment resulted in rapid breakdown of αs- and β-casein during subsequent aseptic storage. Maximum rates of proteolysis were observed at storage temperatures of 37–45 °C, but the reaction was strongly inhibited by storage at 55 °C and by increased holding time at 140 °C during the UHT sterilization. Iodate-induced proteolysis of purified αs1-and β-casein was detected only with solutions in the serum phase of raw milk; no proteolysis occurred with solutions in 01·M-phosphate buffer (pH 6·7) or in milk ultrafiltrate, irrespective of whether whey proteins and lactose were also added. Thus, it appears that iodate increased the activity of one or more proteolytic components which were present in milk and were unable to pass through an ultrafiltration membrane. However, it is unlikely that iodate acts by increasing the activity of proteinases produced by contaminant bacteria; the presence of iodate did not affect the activity of a proteolytic enzyme isolated from Pseudomonas fluorescens PM-1. Furthermore, iodate promoted protein breakdown during storage of milk drawn aseptically from the cow and subsequently UHT processed. It is suggested that iodate increased the activity of native milk proteinases, other than plasmin which was inactivated by UHT treatment, possibly by preventing thiol-disulphide exchange reactions during the heating process.

Type
Original Articles
Information
Journal of Dairy Research , Volume 48 , Issue 1 , February 1981 , pp. 115 - 122
Copyright
Copyright © Proprietors of Journal of Dairy Research 1981

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References

REFERENCES

Anderson, M. & Andrews, A. T. (1977). Journal of Dairy Research 44, 223–235.CrossRefGoogle Scholar
Andrews, A. T. & Cheeseman, G. C. (1971). Journal of Dairy Research 38, 193–207.CrossRefGoogle Scholar
Aschaffenburg, R. & Drewry, J. (1957). Biochemical Journal 65, 273–277.CrossRefGoogle Scholar
Bramley, A. J. (1976). Journal of Dairy Research 43, 205–211.CrossRefGoogle Scholar
Corradini, C. & Peois, P. P. (1979). Journal of Dairy Research 46, 227–229.CrossRefGoogle Scholar
Cousins, C. M., Sharpe, M. E. & Law, B. A. (1977). Dairy Industries International 42(7), 12–17.Google Scholar
Davies, F. L., Underwood, H. M.,Perkin, A. G. & Burton, H. (1977). Journal of Food Technology 12,115–129.CrossRefGoogle Scholar
Driessen, F. M. & Stadhouders, J. (1978). Zuivelzicht 70, 994–996.Google Scholar
Driessen, F. M. & Van Der Waals, C. B. (1978). Netherlands Milk and Dairy Journal 32, 245–254.Google Scholar
Eioel, W. N., Hofmann, C. J., Chibber, B. A. K., Tomioh, J. M., Keenan, T. W. & Mertz, E. T. (1979). Proceedings, National Academy of Sciences of the USA 76, 2244–2248.Google Scholar
Halpaap, I., Reimerdes, E. H. & Klostermeyer, H. (1977). Milchwissenschaft 32, 341–346.Google Scholar
Hull, M. E. (1947). Journal of Dairy Science 30, 881–884.CrossRefGoogle Scholar
Humbert, G. & Alais, C. (1979). Journal of Dairy Research 46, 559–571.CrossRefGoogle Scholar
Kaminooawa, S., Mizobuchi, H. & Yamauchi, K. (1972). Agricultural and Biological Chemistry 36, 2163–2167.CrossRefGoogle Scholar
Kaminooawa, S. & Yamauchi, K. (1972). Agricultural and Biological Chemistry 36, 2351–2356.CrossRefGoogle Scholar
Kiddy, C. A., Rollins, R. E. & Zikakis, J. P. (1972). Journal of Dairy Science 55, 1506–1507.CrossRefGoogle Scholar
Law, B. A. (1979). Journal of Dairy Research 46, 573–588.CrossRefGoogle Scholar
Law, B. A., Andrews, A. T. & Sharpe, M. E. (1977). Journal of Dairy Research 44, 145–148.CrossRefGoogle Scholar
Law, B. A., Sharpe, M. E. & Chapman, H. R. (1976). Journal of Dairy Research 43, 459–468.CrossRefGoogle Scholar
Reimerdes, E. H. & Klostermeyer, H. (1976). Methods in Enzymology 45, 26–28.CrossRefGoogle Scholar
Samuelsson, E. G. & Boroström, S. (1973). Milchwissenschaft 28, 25–26.Google Scholar
Skudder, P. J., Thomas, E. L., Pavey, J. A. & Perkin, A. G. (1981). Journal of Dairy Research 48, 99–113.CrossRefGoogle Scholar
Snoeren, T. H. M., Van Derspek, C. A., Dekker, R. & Both, P. (1979). Netherlands Milk and Dairy Journal 33, 31–39.Google Scholar
Storrs, A. B. & Hull, M. E. (1956). Journal of Dairy Science 39, 1097–1103.CrossRefGoogle Scholar
Tomich, J. M., Eigel, W. N. & Chibber, B. A. K. (1976). Federation Proceedings 35, 1487.Google Scholar
Warner, R. C. & Polis, E. (1945). Journal of American Chemical Society 67, 529–532.CrossRefGoogle Scholar
West, F. B., Adams, D. M. & Speck, M. L. (1978). Journal of Dairy Science 61, 1078–1084.CrossRefGoogle Scholar