Hydrodynamic Characterization of the Formation of Alpha-Tocopherol Nanoemulsions in a Microfluidizer

The use of nanoemulsions produced by microfluidization as delivery systems for nonpolar functional compounds such as bioactive lipids, drugs, flavors, and antioxidants has raised increasing interest mainly in food, pharmaceutical, and cosmetic industries. Despite the high surface-to-volume ratio handled in fluid microchannels, which is beneficial for the higher mass and heat transfer (with a shorter residence time), the small cross-section is a major disadvantage for achieving a good mixture. A commonly used technique to understand and characterize flow in micromixers is the determination of residence time distribution (RTD). This distribution allows determining the effect of mixing on the behavior of a fluid by knowing the mean residence time of molecules within the channels and thus achieving a process design leading to improved product quality. This time, must be adequate to allow the breakdown of the droplets and absorption of emulsion compounds.