Food emulsifiers are also called surfactants, or substances that turn incompatible liquids into uniformly dispersed phases (emulsions). When added to food, they can significantly reduce the interfacial tension between oil and water and make them incompatible. Dissolved oils (hydrophobic substances) and water (hydrophilic substances) form food additives that stabilize emulsions.

On the one hand, the emulsifier forms a thin molecular layer on two mutually repellent phases, reduces the surface free energy of the entire system, and forms a new interface. The emulsifier molecule has two types of hydrophilic and lipophilic groups. Groups can be adsorbed on the mutually repellent phases of oil and water to form a thin molecular layer, which reduces the interfacial tension of the two phases. That is, the lipophilic part of the oil molecule and the emulsifier is one side, and the water molecule and the emulsifier are one side. The hydrophilic part is the other side, and the interaction between the two sides changes the interfacial tension;

On the other hand, by forming a protective adsorption layer on the surface of the droplet, a strong steric stabilization effect is given to the droplet. Generally, the greater the amount of emulsifier added, the greater the decrease in interfacial tension. In this way, the original incompatible materials can be uniformly mixed to form a homogeneous dispersion system, which changes the original physical state, thereby improving the internal structure and quality of the food.