## 3 Factors Influencing and Mechanistic Pathways in Egg Yolk Emulsification
### Chemical Treatment
#### 3.1.1 pH and Ionic Strength
The above-discussed research studies examining the influence of pH and ionic strength on egg yolk emulsifying properties (summarized in Table 1) offers important insights into how these factors affect protein adsorption and emulsion stability. However, these studies are somewhat constrained by their focus on controlled environments, which may not accurately reflect the complexities of real-world food systems. Additionally, the research primarily examines pH and ionic strength in isolation, without accounting for potential interactions with other food ingredients and variables such as temperature or processing techniques. Despite these limitations, the findings are essential for refining egg yolk formulations across various food applications, allowing for better control of texture, stability, and functionality in products like sauces, dressings, and emulsified foods. Figure 4: Adsorption of Na\({}^{+}\) and Ca\({}^{2+}\) on granules at pH 5–10 and adsorption of Cl\({}^{-}\) at pH 2 and 3. Adapted with permission from [PERSON] et al. [33]. 2022, Elsevier. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**pH and Ionic Strength**} \\ \hline
**Conditions** & & **Findings** & **Recommendation/Application** & **Reference** \\ \hline \(\bullet\) & pH: 3.5, 4.5, 6.0, 7.5, and 8.5 & \(\bullet\) & ES decreased with increasing pH and ionic strength & Optimum values of pH and ionic strength were found to be 4.61 to 7.43 and 0.10 to 0.47, respectively & [29] \\ \(\bullet\) & Ionic strength: 0.5, 0.30, 0.45, & \(\bullet\) & ES increased with increasing pH and ionic strength were found to be 4.61 to 7.43 and 0.10 to 0.47, respectively & [29] \\ \(\bullet\) & Ionic strength: 0.3, 0.6, 1.2, & \(\bullet\) & ES increased with increase pH & Highest EAI and ESI at pH 7 and 10, respectively & [30] \\ \(\bullet\) & Ionic strength: 0.5, 0.30, 0.45, & \(\bullet\) & ES increased with NaCl concentration till 1.8\% and decreased with further increase & \\ \(\bullet\) & Ionic strength: 0.3, 0.6, 1.2, & \(\bullet\) & ES increased with increase pH & Highest EAI and ESI at pH 7  
\begin{table}
\begin{tabular}{c c c c} \hline \multicolumn{4}{c}{**Egg yolk complex formation**} \\ \hline
**Complex** & **Findings** & **Mechanism** & **Reference** \\ \hline \multirow{4}{*}{\(\bullet\)} & Egg yolk–octenyl succinic anhydride (OSA) & & Strong electrostatic interaction between egg yolk and HPDSP & \\  & Egg yolk–prodcenyl succinic anhydride (OSA) & Complex of egg yolk–HPDSP & causes the yolk aggregates to crack & \\  & Egg yolk–hydroxpropyl & emulsion stability than egg & or expand to form smaller yolk & [38] \\  & distarch phosphate (HPDSP) & yolk–OSA starch & granules. These smaller egg yolk & \\  & & yolk–OSA & granules tend to make maximum & \\  & & contact with HPDSP & \\ \hline \multirow{4}{*}{High-density lipoprotein (HDL)-phosvitin} & \multirow{4}{*}{Optimum HDL–phosvitin ratio 5:5} & The synergistic utilization of two proteins with different charges, HDL and phosvitin, allowed for electrostatic interactions within the system, resulting in the formation of stable electrostatic complexes & \\  & & & \\