*2.10. Interface Protein Absorption (AP) and Interface Protein Content (*Γ*)*

AP and Γ were measured according to the methods of Liang and Tang [26]. The fresh emulsion (1 mL) was centrifuged for 30 min at a rate of 10,000 r/min, resulting in separation into an upper layer of greasy emulsion and a lower layer of protein supernatant. The upper layer was eliminated carefully, and the lower supernatant was collected with an injector and filtered through a 0.22 μm needle-shaped filter. BSA was used as the standard protein, and the protein concentration of the lower supernatant was tested with the Lowry method. The AP and Γ were calculated as follows:

$$\text{AP} = \frac{\mathbb{C}\_0 - \mathbb{C}\_s}{\mathbb{C}\_0} \times 100\% \,\, \, \, \tag{6}$$

Γ = *C*<sup>0</sup> − *Cs* 1 − ϕ 6ϕ *d*- 3,2 , (7)

where *C*<sup>0</sup> is the protein concentration in the protein solution used to prepare the emulsion (10 mg/mL); *Cs* denotes the protein concentration of the lower supernatant layer after centrifuging the emulsion (mg/mL); Γ represents the interface protein content (mg/m2); ϕ stands for the oil volume fraction (0.1), and *d*- 3,2 refers to the surface area average particle size of the emulsion, which was measured using 1.0% SDS as the dispersing agent (μm).

#### *2.11. Confocal Laser Scanning Microscopy*

The microstructure of the emulsion was analyzed via confocal laser scanning microscopy (CLSM; FV1200, Olympus, Japan) according to the method of Liu [27]. The emulsion (20 μL) was collected and added to a centrifuge. Simultaneously, 10 μL of 0.1% (*w/v*) Nile red methanol solution and 10 μL 1.0% (*w/v*) Nile blue aqueous solution were added; the reaction was performed in the dark for 15 min. The mixture (10 μL) was collected to produce films and observed with a 100× oil immersion lens. The resolution of the scanning images was 1024 × 1024. Proteins were stained with Nile blue, and laser excitation was performed at an excitation wavelength of 633 nm and a detection wavelength of 655–755 nm. Oil phase dyeing was performed with Nile red, followed by laser excitation at an excitation wavelength of 559 nm and a detection wavelength of 570–625 nm.

#### *2.12. Rheological Properties*

The rheological properties of the emulsion were measured with a rheometer (Discovery DHR-2 Dynamic Shear Rheometer, TA, Milford, MA, USA). A 40 mm plate was used to test the apparent viscosity of the emulsion within the shear rate range of 0.1–200 s<sup>−</sup>1.
