Phospholipid Modification Techniques and Their Role in Emulsion Systems

1. Introduction
Phospholipids are amphiphilic molecules widely used in food, cosmetic, and material formulations due to their ability to stabilize oil–water interfaces. To meet industrial processing requirements, various modification techniques have been developed to enhance phospholipid performance, particularly in emulsion systems. Modifying phospholipids can improve their physicochemical properties, processing adaptability, and functional stability.
2. Major Phospholipid Modification Techniques
Phospholipid modification can be achieved through physical, chemical, or enzymatic methods, each targeting structural or functional changes:

Physical modification: Techniques such as ultrasonic treatment, thermal processing, and high-pressure homogenization alter molecular arrangement and particle size distribution, improving dispersibility and emulsion stability.


Chemical modification: Reactions including esterification, acylation, and hydrogenation introduce functional groups that adjust polarity and hydrophilic–lipophilic balance, enhancing compatibility with diverse formulation systems.


Enzymatic modification: Lipases or phospholipases selectively hydrolyze or rearrange phospholipid molecules under mild conditions, allowing controlled modification while preserving structural integrity. Enzymatic methods are increasingly used for green processing and precise functional tuning.

3. Structural and Functional Changes after Modification
Modified phospholipids often display changes in polarity, molecular mobility, and interfacial activity. These changes influence adsorption kinetics at oil–water interfaces, membrane film strength, and droplet interactions in emulsions. By adjusting modification degree, phospholipids with tailored particle size, interfacial tension, and stability can be obtained, suitable for various emulsion formulations.
4. Role in Emulsion Systems
In emulsion systems, phospholipids stabilize dispersed phases by lowering interfacial tension, forming protective interfacial films, and preventing coalescence. Modified phospholipids further enhance:

Interface adsorption: Increased interaction between polar head groups and aqueous phase improves molecular orientation at the interface.


Film reinforcement: Adjustments in fatty acid chain structure enhance film density and flexibility.


Synergistic effects: When combined with proteins, polysaccharides, or other surfactants, modified phospholipids can produce stronger and more stable emulsions.

5. Applications and Development Trends
Phospholipid modification is applied in beverages, sauces, baked products, and powdered formulations. Emerging trends include:

Development of environmentally friendly, green modification processes.


Design of multi-component emulsions with improved stability.


Application of nanotechnology for precise control of phospholipid structure and interfacial behavior.

6. Conclusion
Phospholipid modification techniques provide effective tools for optimizing emulsion system performance. Understanding the relationship between molecular structure and interfacial function enables the design of emulsions with enhanced stability, consistency, and process adaptability, supporting advanced food and material product development.