## 3 Results and Discussion
### Emulsion Stability  
#### 3.2.1 Untreated CPC-Stabilized Emulsions  
The Turbiscan tool enables quick identification and monitoring of destabilization mechanisms in emulsion systems [33; 34; 42]. It detects migration (sedimentation, creaming) or particle size change (coalescence) of a dispersed phase over time, which leads to a variation in backscattering (\(BS\)) and transmission (T) of light intensity [43]. The instrument makes it possible to determine and compare the kinetics of destabilization of many samples and to determine the stability parameter--Turbiscan Stability Index (_TSI_) [33; 34; 43]. The results of the stability measurements of \(\mathrm{eC_{g}}\) and \(\mathrm{eC_{s}}\) presented as \(BS\) (%) profiles over the entire height of the sample during the 28-day storage are shown in Figure 1 and the _TSI_ kinetics of their global destabilization are presented in Figure S2. Particle migration was observed in both types of emulsion during the storage period. In the case of \(\mathrm{eC_{g}}\), it was primarily instability due to gravity separation (creaming) accompanied by an increase in \(BS\) intensity in the upper part of the emulsion and a decrease in the lower part due to migration of droplets from the bottom of the sample (Figure 1a), while for the \(\mathrm{eC_{s}}\), creaming of the emulsion was accompanied by sedimentation and the increase in \(BS\) intensity in the lower part of the sample (Figure 1e). The long-term stability of emulsion is closely related to the particle size of the internal phase and its distribution [44] but also to the rheological properties of emulsion [45; 46; 47]. Firstly, the narrow PSD and small mean droplet sizes are associated with more stable emulsions [48]. This is attributed to the significant effect of droplet size on the gravitational separation of the emulsions [49]. Secondly, proteins as amphiphilic molecules adsorb at internal interfaces, which results in decreasing the interfacial tension as well as the formation of compact, resistant to ruptures, adsorption layers at the surface of the oil, providing repulsive steric and electrostatic interactions between droplets, which avoid their coalescence [47; 50]. The rheological properties of adsorbed layers influence the rheology of an emulsion as a whole [46]. Figure 1: _Cont._  
The stability results for both emulsions were reflected in their PSD data (Table 1) and shear rheological properties (Table 2) as eC\({}_{\rm g}\) was low-viscosity Newtonian fluid (\(\eta\) = 3.42 mPa\(\cdot\)s; \(n\) = 1) with a mean volume diameter below 0.5 \(\mu\)m, whereas eC\({}_{\rm s}\) with a particle size approximately 70 times larger was a non-Newtonian fluid exhibiting the shear-thinning and yield stress (the Herschel-Bulkley model was used to describe the flow curves quantitatively) as well as more than twice the viscosity. Larger particles or their  
Figure 1: The backscatter (\(BS\)) profiles of CPC\({}_{\rm g}\)- and CPC\({}_{\rm s}\)-stabilized emulsions as a function of sample height tested over 28 days, where (**a**,**e**) untreated samples (eC\({}_{\rm g}\) and eC\({}_{\rm s}\)); (**b**,**f**) samples with 0.1 M NaCl (eC\({}_{\rm g}\)N and eC\({}_{\rm s}\)N); (**c**,**g**) samples heated to 95 \({}^{\circ}\)C (eC\({}_{\rm g}\)T and eC\({}_{\rm s}\)T); (**d**,**h**) samples with 0.1 M NaCl heated to 95 \({}^{\circ}\)C (eC\({}_{\rm g}\)NT and eC\({}_{\rm s}\)NT), respectively. aggregates under the influence of gravity fell to the bottom of the eC\({}_{\rm s}\), and a thickened emulsion (to a height of approx. 23 mm) was formed (Figure 1e). In turn, upward cream in eC\({}_{\rm s}\) and eC\({}_{\rm g}\) was driven by the buoyancy of the emulsion droplets in the continuous phase due to density differences between the dispersed particles and the serum phase. It is a well-known phenomenon in oil-in-water food emulsions as edible oils have lower densities than water [51].