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An improved method for determining the nitrogen solubility of caseinates

Published online by Cambridge University Press:  01 June 2009

Wolfgang Kneifel  and
Anne Beurel
Wolfgang Kneifel
Affiliation:
Department of Dairy Research and Bacteriology, Agricultural University, A-1180 Vienna, Austria
Anne Beurel
Affiliation:
Ecole Nationale d'Ingénieurs des Techniques des Industries Agro-Alimentaires, 44072 Nantes, France
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Summary

The nitrogen solubility index (NSI) method for the examination of caseinates was evaluated. It was found that widely scattering NSI values are mainly due to ineffective centrifugation and filtration of the caseinate dispersion. In order to avoid this, an improved combined centrifugation–filtration procedure was developed as an alternative to the original NSI method, using an Amicon micropartition system MPS-1 equipped with discs of filter paper. The micropartition devices can be centrifuged in a Gerber centrifuge of the type used for butyromctric fat determination. Several types of caseinates were evaluated with the new method and yielded a markedly smaller range of single values than were obtained with the NSI method.

Type
Original Articles
Information
Journal of Dairy Research , Volume 57 , Issue 2 , May 1990 , pp. 207 - 212
Copyright
Copyright © Proprietors of Journal of Dairy Research 1990

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References

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