Pure and mixed gels prepared from a whey protein isolate (WPI) and skim milk powder (SMP) by heating to 90°C at pH 4·3-4·6, with or without fat globules, were studied by mechanical testing. The testing involved compression to 20% deformation and oscillatory rheometry (storage and loss moduli, G′ and G″, respectively). Compressive stresses of mixed gels varied between 0·7 and 1·9 kPa. Gels containing WPI reached higher G′ values and had shorter gel-set times than those containing SMP. SMP based gels were more elastic than WPI based gels as revealed by the lower loss tangent (tan δ = G″ G′) values achieved after 17 min (0·18-0·23 versus approx. 0·38, respectively). Addition of fat resulted in higher compressive stresses and shorter gel-set times but did not affect the initial gelation rate. Gels with different viscoelastic and mechanical properties were prepared with varying amounts of WPI, SMP and emulsified fat.
|Number of pages||7|
|Journal||Food Research International|
|State||Published - 1993|
Bibliographical noteFunding Information:
This work was partly supported by a grant from the Agency for International Development (USAID), grant 5 13-560&G-00-1062-00 and by the NE Dairy Foods Research Center. It was accomplished while the senior author was a Ful- bright scholar at the Department Cornell University.
Copyright 2014 Elsevier B.V., All rights reserved.
- compressive strength
- mechanical properties
- skim milk powder
- whey protein
ASJC Scopus subject areas
- Food Science