African Journal of Food Science Vol. 4(1), pp.016-025, January,  2009

ISSN 1996-0794 © 2010 Academic Journals  

Full Length Research Paper

Emulsifying functionality of enzyme-modified milk proteins in O/W and mayonnaise-like emulsions   Gaurav Gaonkar1*, Rathna Koka2, Ken Chen2 and Bruce Campbell2   1Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616, U.S.A. 2Kraft Foods Global Inc, 801 Waukegan Road, Glenview, IL 60025, U. S. A.   * Corresponding author- e-mail: agaonkar@juno.com.  Tel: 847 478 1716. Fax: 847 646 3440.   Accepted 26 October, 2009

Abstract

Emulsifying functionality of milk proteins such as whey protein concentrate (WPC), whey protein isolate (WPI), casein, and enzyme-modified WPC, WPI, and casein was investigated in a O/W emulsion.  Enzyme-modified samples were selected based on the sensory evaluation and their functionality was tested in mayonnaise-like emulsion and compared to the mayonnaise emulsion prepared using egg components.  Casein and hydrolyzed casein were not used for making mayonnaise-like emulsion because of their undesirable taste and poor emulsion stability.  At a given concentration of protein, egg components provide smaller oil drops and creamier mayonnaise compared to WPC and WPI.  However, WPC provides a thicker mayonnaise-like emulsion compared to the egg proteins and WPI.  Both WPC and WPI provided products with much thicker texture.  However, the texture was not creamy compared to the emulsion containing the egg components.  Enzyme-modified WPC samples are significantly less functional than the enzyme-modified WPI samples.  Emulsifying functionality in mayonnaise was decreased as the level of WPI or enzyme-modified WPI was decreased.  At all protein levels studied, protease (Multifect Neutral)-treated WPI is more functional than transglutaminase-treated WPI.  Enzyme modification, in general, leads to a decrease in the emulsifying functionality of WPC and WPI in mayonnaise-like emulsions.

Key words: Milk proteins, whey proteins, WPC, WPI, casein, enzyme modification.