Whole casein surface tension

The surface tensions of p-casein and whole casein at this bulk concentration are very similar the former being just slightly more surface-active (Maldonado-Valderrama and Langevin, 2008). This... 

Surface Tension, Surface Rheological Properties (Oscillation Frequency = 0.1 Hz), and Thin Film Thickness of Whole Casein and P-Casein in Buffer Solutions at pH 7.4, /=16.4mM, T=20°C... 

Regarding the systems used in this study, we use the same proteins as in the previous section (whole casein and P -casein) and they are mixed with Tween 20, respectively. This is a low molecular weight surfactant used in the food industry, which is water soluble and nonionic. The different behavior of these two mixed systems is again discussed on the basis of fundamental magnitudes such as surface tension and foam film thickness. 

Let us now evaluate the surface properties of the mixed system formed by whole casein and Tween 20 also shown in Figure 10.4. Despite having similar surface tensions (Table 10.1), the structural... 

Firstly, the stability of the foam formed by P-casein and whole casein appears very different, the former being more stable. In order to further investigate this issne, we evalnate several surface properties of these two proteins. The surface tension and surface rheology do not seem to be accurate enough to account for this large difference in foam stability, since they show very similar values. However, the thickness of the foam films stabilized by the two proteins respectively seems to determine the ultimate behavior of the foam. Hence, the thicker foam film measured for P-casein probably prevents coalesce of air bubbles resulting in more stable foam formed by this protein as compared to whole casein. 

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