Lecithin as Emulsifier
An Excellent Emulsifier – Preferred choice of most formulators
Lecithin’s molecular structure makes it an effective emulsifier for the interaction of water and oil. Phospholipids, the major component of lecithin, are partly hydrophilic (attracted to water) and partly hydrophobic (repelled from water). It is lecithin’s ability to simultaneously interact with both oil and water that makes it such an effective and stable emulsifier.
When introduced into a system, an emulsifier such as lecithin acts to help maintain a stable emulsion between two unmixable liquids. The emulsifier decreases the surface tension between the two liquids and allows them to mix and form a stable, heterogeneous dispersion.
Depending on the formulation an appropriate type of lecithin can be chosen with the help of HLB (Hydrophilic and Lipophilic Balance) chart.
| Water in Oil (1-6) | Water in Oil or Oil in Water (6-8) | Oil in Water (8-12) | |||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Favors Water in Oil Emulsions |  |
Favors Oil in Water Emulsions | |||||||||
Usage of Lecithin in both emulsions:
- 1 – 5% of the oil/fat in W/O emulsions
- 5 – 10% of the oil/fat in O/W emulsions