## 3 Results
### Comparison of Physical Stability of Emulsions Stabilized by Glycosylated Hydrolysates  
The mean particle size, \(\zeta\)-potential and creaming index (CI) are exhibited in Figure 3A-C, respectively, which were used to analyze the physical stability of the CLA emulsions stabilized by GPP-A and GPP-B. The mean particle size is the important index to analyze emulsion stabilities [32; 33]. As shown in Figure 3A, the mean particle size of the emulsions formed by GPP-A and GPP-B was observably and significantly lower than that of the WPI-stabilized emulsion (\(p<0.05\)). It indicated that the combination of glycosylation and hydrolysis to modify the WPI as emulsifiers could significantly reduce the mean particle size of the emulsions, thus improving the physical stability. From Figure 3B, the absolute potential of the CLA emulsions loaded by GPP-A and GPP-B increased by 133.13 and 74.23%, in comparison with that of the WPI-loaded emulsion. Furthermore, the GPP-A-stabilized emulsion had a higher absolute \(\zeta\)-potential than the CLA emulsion loaded by GPP-B. It can be inferred, from Figure 3A,B, that the glycosylated WPI tended to adsorb on the oil-water interface, thus increasing the repulsive term and restraining the aggregation of emulsion droplets. Additionally, the hydrophobic groups of hydrolyzed protein were exposed, which could improve the surface hydrophobicity and the molecular flexibility of protein [12]. These were conducive to adsorption on the surface of the oil droplets, thus effectively reducing  
Figure 3: Changes in average particle size (**A**); zeta\(-\)potential (**B**); creaming index (**C**) and macroscopic pictures when stored for 15 days at 25 \({}^{\circ}\)C (**D**) of CLA emulsions stabilized by GPP-A and GPP-B. Values with different letters are significantly different (\(p<0.05\)). the interfacial tension, and forming a smaller particle size and more stable emulsions [30]. As shown in Figure 3C, the CI of the CLA emulsions stabilized by the WPI, GPP-A and GPP-B increased significantly with storage time (0-15 days). The CI of the emulsions loaded by the WPI and GPP-B was 82.6 and 8.37% when stored for 15 days, while there was no significantly cream layer forming in the GPP-A-loaded emulsion, from the inserted image of Figure 3D. These results indicated that the combination of glycosylation and hydrolysis could significantly reduce the CI of CLA emulsions. Furthermore, GPP-A as the emulsifier could more easily be adsorbed to the oil-water interface, thus inhibiting the aggregation of the oil droplets. It suggested that the emulsions formed by hydrolysates of the whey protein-linear dextrin showed a higher absolute \(\zeta\)-potential and smaller average particle size than that of the whey protein-loaded emulsion [34]. The fraction of interfacial adsorption (Fads) is displayed in Figure 4. Generally, Fads is the key factor for the stability of emulsions and for preventing oil droplets from coalescing. From Figure 4, the Fads of the CLA emulsions formed by the WPI, GPP-A and GPP-B was 48.79, 89.24 and 68.17%, respectively. It indicated that the Fads of emulsions formed by glycosylated hydrolysates as emulsifiers through the two pathways were more than those of the WPI-loaded emulsion (\(p<0.05\)). A similar result showed that the Fads of emulsions formed by a walnut protein isolate-glucose conjugate was significantly higher than a walnut protein isolate-loaded emulsion [35]. Additionally, the emulsions stabilized by the hydrolysates of egg-yolk protein had higher Fads in comparison with the egg-yolk protein-loaded emulsion [36]. Meanwhile, the CLA emulsion formed by GPP-A had more Fads than pathway B as the emulsifier (\(p<0.05\)). The GPP-A molecule was significantly expanded with a higher reaction degree, and more hydrophobic groups were exposed. A study suggested that the glycosylated products could wrap on the surface of the oil droplets, resulting in the improvement of Fads [37].