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Epimerization of lactose to free lactulose in heated model milk solutions

Published online by Cambridge University Press:  01 June 2009

Barry D. Greig  and
Gerald A. Payne
Barry D. Greig
Affiliation:
*National Institute for Research in Dairying (University of Reading), Shinfield, Reading, RG2 9AT, UK
Gerald A. Payne
Affiliation:
*National Institute for Research in Dairying (University of Reading), Shinfield, Reading, RG2 9AT, UK
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Summary

The kinetics of the epimerization of lactose to lactulose were determined for two ‘model milk’ solutions, one containing lactose and the other lactose and lysine. The lysine was added to lactose to determine whether amino groups of proteins act as base catalysts promoting the production of free lactulose. The presence of lysine actually reduced the rate of production of free lactulose, presumably by the formation of amino-sugar complexes. The rate of production of free lactulose over the range of processing conditions was shown to be first order for both systems. Thermal effects on lactose were shown to be complex. The epimerization of lactose to lactulose was reversible and both sugars were thermally decomposed to their monosaccharides. The difference in the rate of production of free lactulose between the lactose, and the lactose and lysine solutions was also observed in processed milk and its ultrafiltrate (protein free).

Type
Original Articles
Information
Journal of Dairy Research , Volume 52 , Issue 3 , August 1985 , pp. 409 - 417
Copyright
Copyright © Proprietors of Journal of Dairy Research 1985

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References

REFERENCES

Adachi, S. 1959 The mechanism of the degradation of lactose in strongly heated milk, 15th International Dairy Congress, London 3 1686–1690Google Scholar
Adachi, S. & Patton, S. 1961 Presence and significance of lactulose in milk products; a review. Journal of Dairy Science 44 1375–1393CrossRefGoogle Scholar
Andrews, G. R. 1984 Distinguishing pasteurized, UHT and sterilized milks by their lactulose content. Journal of the Society of Dairy Technology 37 92–95CrossRefGoogle Scholar
Geier, H. & Klostermeyer, H. 1980 [Enzymic determination of lactulose.] Zeitschrift für Lebensmittel- Untersuchung und -Forschung 171 443–445CrossRefGoogle Scholar
Geier, H. & Klostermeyer, H. 1983 Formation of lactulose during heat treatment of milk. Milchwissenschaft 38 475–477Google Scholar
Khramtsov, A. G., Kravchenko, E. F. & Matvievskii, V. Ya. 1978 Lactulose production from lactose solutions. 20th International Dairy Congress, Paris E 966–968Google Scholar
Matvievskii, V. Ya., Kravchenko, E. F. & Khramtsov, A. G. 1978 [Effect of pH of medium, temperature and duration of heating on effectiveness of lactulose accumulation in lactose solution.] Trudy Vsesoyuznyí Nauchno-issledovatel skii Institut Maslodel'noí i Syrodel'noí Promyshlennosti Nauehno-proizvodstvennogo Ob “edineniya ‘Uglich’ no. 26 13–18, 83Google Scholar
Parrish, F. W., Talley, F. B., Ross, K. D., Clark, J. & Phillips, J. G. 1979 Sweetness of lactulose relative to sucrose. Journal of Food Science 44 813–815CrossRefGoogle Scholar
Petuely, F. Z. 1957 [Bifidus flora in bottle-fed infants through bifidogenic substances.] Zeitschrift für Kinderheilkunde 79 174–179CrossRefGoogle Scholar
Richards, E. L. & Chandrasekhara, M. R. 1960 Chemical changes in dried skim-milk during storage. Journal of Dairy Research 27 59–66CrossRefGoogle Scholar