Heat-Induced Soy−Whey Proteins Interactions:  Formation of Soluble and Insoluble Protein Complexes

Rodrigo R. Roesch and Milena Corredig*
Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
J. Agric. Food Chem., 2005, 53 (9), pp 3476–3482
DOI: 10.1021/jf048870d
Publication Date (Web): April 2, 2005
Copyright © 2005 American Chemical Society
*

 To whom correspondence should be addressed. Fax:  519-824-6631. E-mail:  mcorredi@uoguelph.ca.

Abstract

The aggregation behavior during heating of a solution containing soy protein and whey protein isolate (WPI) was studied using rheology, confocal microscopy, gel filtration, and electrophoresis. Soy/WPI mixtures formed gels at 6% total protein concentration with a high elastic modulus (G‘) and no apparent phase separation. The ratio of soy to WPI was fundamental in determining the type of network formed. Systems containing a high soy to WPI ratio (>70% soy protein) showed a different evolution of the elastic modulus during heat treatment, with two apparent stages of network development. Whey proteins formed disulfide bridges with soy proteins during heating, and at low ratios of soy/WPI, the aggregates seemed to be predominantly formed by 7S, the basic subunits of 11S and β-lactoglobulin. Size exclusion chromatography indicated the presence of high molecular weight soluble complexes in mixtures containing high soy/WPI ratios. Results presented are the first evidence of interactions between soy proteins and whey proteins and show the potential for the creation of a new group of functional ingredients.

Keywords: Soy proteins; milk proteins; aggregation

Tools

SciFinder Links

SciFinder subscribers:  Click to sign in | Not a SciFinder subscriber? Learn more at www.cas.org

History

  • Published In Issue May 04, 2005
  • Received for review July 8, 2004. Revised manuscript received December 10, 2004. Accepted January 13, 2005. This work was supported by the Hannam Soybean Utilization Fund and the Natural Sciences and Engineering Council of Canada.

Recommend & Share

Related Content

Other ACS content by these authors: