## 2 Emulsifying Properties of Egg Yolk and Its Components  
Egg yolk is a complex system with multiple structural levels, as shown in Figure 2. The process of centrifugation, which involves spinning egg yolk at high speeds, allows for its easy separation into its two primary components, plasma and granules; this separation enables the individual study and utilization of each component, providing valuable insights into the unique properties and potential applications of egg yolk in various fields. Several authors have developed different methods to separate egg yolk into its components. This  
Figure 1: Overview of factors influencing emulsifying properties of egg yolk. review does not aim to describe these methods, as they have been described in other studies [17; 18; 19]. Egg yolk contains insoluble protein aggregates i.e., granules, which constitute approximately 22% of its dry matter and are rich in protein, containing roughly 50% of its total protein and also 7% of its lipids. Suspended in a clear yellow fluid called plasma, which constitutes about 78% of the yolk's dry matter and consists primarily of low-density lipoproteins (LDLs) with 85% of its composition and 15% livetins, these granules, primarily composed of high-density lipoproteins (HDLs) (70%) and phosvitin (16%), are interconnected by phosphochcalc bridges. Plasma is rich in lipids, containing about 90% of the yolk's total lipids, including almost all of the carotenoids, and also holds 50% of its proteins [4]. Given the varying composition of the egg yolk components, they exhibit varying emulsifying properties. The effectiveness of an emulsifier is assessed based on its emulsifying activity, which refers to its ability to create a protective layer around oil droplets, preventing coalescence and separation, and its emulsion stability, which measures how well the emulsifier can preserve the emulsion's structure over time [20]. According to [PERSON] and [PERSON] [21], no difference was observed in the emulsifying activity of egg yolk, plasma, and granules, although granules demonstrated a superior emulsion stability compared to whole yolk and plasma. In a study by [PERSON] et al. [22], the emulsifying properties of native granules and granules disrupted into HDL, phosvitin, and LDL were compared, with the granules being diluted in 0.17 M NaCl solution for the native granules and 0.5 M NaCl solution for the disrupted granules; the results showed that disrupted granules exhibited superior emulsifying activity and emulsion stability compared to the native granules. Native granules had low solubility (-13%), whereas monovalent sodium from the addition of NaCl (0.5 M final concentration) disrupted the phosphochcalc bridges between HDL and phosvitin, liberating them into the solution and increasing the solubility to 95%. Furthermore, the emulsions formed using native granules displayed a bimodal droplet size distribution, achieving a monomodal size distribution only at 1.5% protein concentration. In contrast, emulsions formed with disrupted granules showed a monomodal droplet size distribution starting at 0.4% protein concentration. Regarding creaming, emulsions prepared with native granules exhibited creaming levels above 60% at all protein concentrations (0.15, 0.4, 0.8, and 1.5% \(w/v\)), whereas emulsions formulated with disrupted granules demonstrated a reduction in creaming from 63% to 40% as the protein concentration increased from 0.15% to 1.5% [22]. Figure 2: Components of egg yolk and schematic diagram for natural protein–lipid supramolecular assembly structure of egg yolk. LDL: low-density lipoprotein; HDL: high-density lipoprotein. Recently, [PERSON] and [PERSON] [23] compared the emulsifying properties of the plasma fraction separated from egg yolk using low centrifugal forces (2000 to 6000\(\times\)\(g\)) for a brief period (5 min), finding no significant difference in the emulsifying capabilities of plasmas fractionated at these centrifugal forces compared to whole egg yolk [23].