Location: Dairy and Functional Foods
Title: Solubility and Viscosity of Dairy Proteins Mixed with Other Food Proteins Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 22, 2010
Publication Date: N/A
Technical Abstract: Multiple protein gels are complex systems, and many aspects of their behavior depend on their combined solubility and miscibility which affects the shear properties. In this study, we examined the effect of adding food proteins step-wise to calcium caseinate (CC) or whey protein isolate (WPI) at their optimal soluble concentration at 25 deg C and 60 deg C. Mixtures of CC or WPI with egg albumin (EA), fish protein isolate (FPI), and soy protein isolate (SPI) were combined to make up 15 g protein which was mixed with water at 25 deg C to form slurries. The slurries were stirred continuously for 15 min and heated to 60 deg C to form gels. At 25 deg C, the optimal solubility and viscosity values of the protein slurries were: CC (1115.8 cP/15 wt%), EA (175.2 cP/35 wt%), FPI (2207.4 cP/30 wt%), SPI (2531.5 cP/10 wt%), and WPI (161.2 cP/35%). Mixing similar ratios of two proteins, for instance CC and EA, resulted in different viscosity values: CC/EA (5:10 wt%) 31.9 cP and CC/EA (10:5 wt%) 535.1 cP. The steady shear apparent viscosity at 60°C, increased slightly for WPI (1.6 cP/0.5 min, and 2.4 cP/45 min) and shear-thickened for EA gels (51.1 cP/0.5 min, and 131.6 cP/45 min), but combined (WPI/EA) the values were 5.3 cP/0.5 min, and 22.1 cP/45 min. CC was pseudo-Newtonian (5.4 cP/0.5 min, and 4.8 cP/45 min), but combined with EA, gel behavior did not change (4.1 cP/0.5 min, and 4.8 cP/45 min). Adding EA to dairy proteins increased their steady shear viscosity. Knowledge of the fundamental gelling behavior of individual food proteins is critical for creating textured foods that combines different types of proteins for a desired gel property.