4. Conclusion
This study showed that different mechanisms act on the stabilization of water-in-oil emulsions. The main stability mechanism against the sedimentation of a water-in-oil emulsion was the steric stability, which depends on the hydrodynamic interactions between the droplets that, in turn, is dependent on the apparent viscosity. Higher water internal volume resulted in more viscous emulsions, increasing the stability. On the other hand, higher volume of less viscous oil showed rapid phase separation. Furthermore, the rapid decrease in the interfacial tension with the emulsifier addition was also important for the formation of small droplets, which resulted in higher stability against gravity force. Other factor was the viscoelasticity of the film at the water–oil interface, which can prevent the coalescence of droplets. Moreover, depending on the composition of the system, a gel network can be formed, resulting in a product with different rheological characteristics and distinct stability mechanisms