# Effects of Supplementation of Different Proteins on the Rheological Properties of Liquid Whole Eggs
## 3 Results  
Rheological properties are essential for understanding high-protein liquid whole egg behavior, because they directly influence critical aspects of food processing and product development [23]. In processes like extrusion, rheology affects fluid flow, pump selection, equipment design, and the adaptation of raw materials to meet specific processing and product design requirements. Proteins, which exhibit both elastic and viscous behavior, play an important role in determining the texture, mouthfeel, and structural integrity of foods. By examining rheological behavior, researchers can better customize protein-based ingredients for improved performance and sensory attributes in food products [24]. The flow properties of added-protein liquid whole eggs were shown to exhibit pseudoplastic behavior. Figure 1a,b illustrate the flow behavior for samples that were heat treated after adding proteins and those that were heat treated before, respectively. The figures show the relationship between shear stress (Pa) on the y-axis and shear rate (1/s) on the x-axis. Figure 1a shows that adding whey and egg white protein then heat treating the samples increases the shear stress, which indicates that liquid whole egg is becoming thicker. At equivalent concentrations, egg white protein-enriched samples show a higher shear stress than whey-fortified samples; this shows that egg white protein has a higher influence on the overall flow behavior of liquid whole egg, making it more viscous and resistant to flow. Meanwhile, Figure 1b shows that without heat treatment, liquid whole eggs with added proteins show a Newtonian-like behavior, meaning that the viscosity of the samples remains constant despite of the applied shear rate. Figure 2a,b display viscosity (mPa-s) on the y-axis against shear rate (1/s) on the x-axis for samples that were heat treated after adding proteins and those which were heat treated before, respectively. Figure 2a shows that the viscosity of samples decreases with increasing shear rate for all samples, indicating a shear thinning behavior when proteins were added before heat treatment. Although all samples show a shear thinning behavior, the highest shear thinning behavior was observed in samples with 5% and 10% added egg white protein. These samples start with the highest viscosity at low shear rates and decreased significantly as the shear rate increases. As for Figure 2b, it is clearly seen that whey protein samples exhibit nearly a Newtonian behavior, where viscosity remains constant with the  
increase in shear rate. Meanwhile, egg white protein samples show a thinning behavior, which was more obvious with the increase in egg white protein concentrations and almost identical to the control group behavior in the sample with 3% added egg white protein. Figure 1: The flow curves of different concentrations of added whey and egg white protein to liquid whole egg: (**a**) pasteurizing after adding proteins at \(60\,\pm\,0.2\,^{\circ}\)C with 3.5 min of holding time; (**b**) pasteurizing before adding proteins at \(60\,\pm\,0.2\,^{\circ}\)C with 3.5 min of holding time. The flow behavior and viscosity data collected experimentally align well with the calculated values using the Herschel-Bulkley model. This alignment confirms that the flow behavior is not a good approximation of the flow behavior. Figure 2: The viscosity curves (shear rate vs. viscosity) of different concentrations of added whey and egg white protein to liquid whole egg: (**a**) pasteurizing after adding proteins at \(60\,\pm\,0.2\,^{\circ}\)C with 3.5 min of holding time; (**b**) pasteurizing before adding proteins at \(60\,\pm\,0.2\,^{\circ}\)C with 3.5 min of holding time. samples exhibit the predicted flow behavior characteristics, validating the Herschel-Bulkley model's accuracy in describing these non-Newtonian properties [22; 25]. Table 1 shows the Herschel-Bulkley model parameters describing the flow behavior of samples that pasteurized after adding the proteins at 60 \(\pm\) 0.2 \({}^{\circ}\)C with 3.5 min of holding time.