Rheology of heated mixed whey protein isolate/cross-linked waxy maize starch dispersions

RAVINDRA, POGAKU; GENOVESE, DIEGO B.; RAO, M. ANDY

FOOD HYDROCOLLOIDS

Elsevier Ltd.

Año: 2004 vol. 18 p. 775 - 781

0268-005X

Dynamic and flow rheological characteristics of mixed whey protein isolate (WPI) and cross-linked waxy maize starch (CWM) gelatinized dispersions (GDs): 5% solids, pH=7.0, 75mM NaCl, were examined at starch mass fractions (smf) from 0 (pure WPI) to 1 (pure CWM). The mixed GDs had lower values of G? than the pure WPI GD, primarily due to the disruptive effect of CWM granules on the WPI network. The point of phase inversion (minimum G? value) was at about smf =0.65. Based on frequency sweep data, the mixed GDs were classified as ´structured liquids´.  Shear stress- shear rate data on the blends showed three different behaviors: WPI GD-like, CWM GD-like, or intermediate between the two depending on the composition. Apparent viscosity-shear rate curves followed the power law model with flow behavior index (n) values of 0.09£ n £0.16 at smf £ 0.2, and 0.47£ n £0.53 at smf ³0.4.