Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-26T11:50:21.340Z Has data issue: false hasContentIssue false
  • English
  • Français

Comparative emulsifying properties of sodium caseinate and whey protein isolate in 18% oil in aqueous systems

Published online by Cambridge University Press:  01 June 2009

John Foley  and
Catherine O'Connell
John Foley
Affiliation:
Department of Food Technology, University College, Cork, Irish Republic
Catherine O'Connell
Affiliation:
Department of Food Technology, University College, Cork, Irish Republic
Get access Rights & Permissions [Opens in a new window]

Summary

Both whey protein isolate (WPI) and Na caseinate gave similar emulsion capacity-concentration profiles at pH 7. The emulsion capacity of aqueous solutions of WPI was relatively independent of pH while the values for caseinate fell in the isoelectric region. Saline (7·59 g/1) compared with aqueous solutions improved emulsion capacity, particularly above pH 7. At low concentration, WPI had greater emulsifying capacity and gave finer globule dispersion than sodium caseinate. Increase in emulsifier concentration, within a certain range, increased stability, improved dispersion and reduced capacity. Ethanol up to about 20% w/w improved the emulsion capacity of both proteins while at 50% the phases separated. Heat treatment (> 65 °C) of WPI solution before emulsion formation impaired capacity and stability. Heat treatment of preformed WPI emulsions did not have the same effect. Na caseinate and WPI each formed a thin continuous layer of relatively uniform thickness over the oil globule surfaces while denatured WPI appeared aggregated and relatively unevenly distributed at the oil-aqueous interface.

Type
Original Articles
Information
Journal of Dairy Research , Volume 57 , Issue 3 , August 1990 , pp. 377 - 391
Copyright
Copyright © Proprietors of Journal of Dairy Research 1990

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

Barry, F., Beechinor, F. & Foley, J. 1988 High-performance liquid chromatography analysis of whey protein products. Irish Journal of Food Science and Technology 12 25–39Google Scholar
Bech, A. M. 1981 The physical and chemical properties of whey proteins. Dairy Industries International 46(11) 25, 27, 29, 31, 33Google Scholar
De Wit, J. N., Klarenbeek, G. & Swinkels, G. A. 1976 [The emulsifying properties of whey protein concentrates.] Zuivelzicht 68 442–445Google Scholar
Foley, J., Brady, J. & Reynolds, P. J. 1971 The influence of processing on the emulsion stability of cream. Journal of the Society of Dairy Technology 24 54–58CrossRefGoogle Scholar
Graf, E. & Müller, H. R. 1965 Fine structure and whippability of sterilized cream. Milchwissenschaf 20 302–308Google Scholar
Green, M. L., Hobbs, D. G. & Morant, S. V. 1978 Intermicellar relationships in rennet-treated separated milk. T. Preparation of representative electron micrographs. Journal of Dairy Research 45 405–411CrossRefGoogle Scholar
Hegarty, G. R., Bratzler, L. J. & Pearson, A. M. 1963 Studies on the emulsifying properties of some intracellular beef muscle proteins. Journal of Food Science 28 663–668CrossRefGoogle Scholar
Jenness, R. & Koops, J. 1962 Preparation and properties of a salt solution which simulates milk ultrafiltrate. Netherlands Milk and Dairy Journal 16 153–164Google Scholar
Kuehler, C. A. & Stine, C. M. 1974 Effect of enzymatic hydrolysis on some functional properties of whey protein. Journal of Food Science 39 379–382CrossRefGoogle Scholar
Morr, C. V., Swenson, P. E. & Richter, R. L. 1973 Functional characteristics of whey protein concentrates. Journal of Food Science 38 324–330CrossRefGoogle Scholar
Murphy, G. M. 1980 Stability studies in model and natural concentrated oil in water emulsions. Ph.D. Thesis, National University of IrelandGoogle Scholar
Schulz, M. E., Thiele, D. & Höft, E. 1968 [Using the Milko-Tester to measure turbidity in determining degree of dispersion of milk fat emulsions.] Milchwissenschaft 23 14–19Google Scholar
Swift, C. E., Lockett, C. & Fryar, A. J. 1961 Comminuted meat emulsions – the capacity of meats for emulsifying fat. Food Technology 15 468–473Google Scholar
Swift, C. F. & Sulzbacher, W. L. 1963 Comminuted meat emulsions. Factors affecting meat proteins as emulsion stabilizers. Food Technology 17 224–226Google Scholar
Wange, J. C. & Kinsella, J. E. 1976 Functional properties of novel proteins: alfalfa leaf protein. Journal of Food Science 41 286–292CrossRefGoogle Scholar