Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/10/2009
Publication Date: 8/18/2009
Citation: Onwulata, C.I., Thomas-Gahring, A.E. 2009. Steady Shear Flow Behavior of Mixed Proteins. Meeting Abstract. (Poster Presentation) ACS - Washington, DC Interpretive Summary: N/A
Technical Abstract: Knowledge of the fundamental flow behavior of protein gels is critical for creating food products using a combination of proteins. Because multiple protein gels are complex systems, many aspects of their flow behavior must be studied to fully understand what effects shear, time, and temperature have on the gels. In this study, we examined the effect of steady shear on the protein gel mixtures of calcium caseinate (CC), egg albumin (EA), fish protein isolate (FPI), soy protein isolate (SPI), wheat gluten (WG), and whey protein isolates (WPI). These proteins and their various combinations (12 g) were mixed with water at 22 deg C to form 12% solid content slurries. The slurries were continuously stirred for 15 min and heated in a water bath to 60 deg C to form gels. Viscosity of the gels was measured at 60 deg C, at a shear rate of 200 rpm for 45 min. The apparent viscosity measurements clearly demonstrate that EA and WPI gels exhibited shear-thickening behavior. EA gels were: 14.5 cP (0.5 min), 50.9 cP (10 min), and 133.1 cP (45 min), and WPI gels were 0.3 cP (0.5 min), 1.6 cP (10 min), and 2.4 cP (45 min); SPI gels were shear-thinning: 34.9 cP (0.5 min), 27.9 cP (10 min), and 24.0 cP (45 min); and WG gels exhibited shear-thickening between 0.5 and 10 min: 48.8 cP and 58.6 cP and shear-thinning after 10 min, at 45 min viscosity was 37.2 cP. CC and FPI were pseudo-Newtonian. Knowledge of flow behavior of individual proteins and their combinations will aid food manufacturers in selecting which proteins to be combined for a desired gel property.