Extending Emulsion Functionality: Post-Homogenization Modification of Droplet Properties

Abstract

Abstract:Homogenizers are commonly used to produce oil-in-water emulsions that consist of emulsifier-coated oil droplets suspended within an aqueous phase. The functional attributes of emulsions are usually controlled by selecting appropriate ingredients (e.g., surfactants, co-surfactants, oils, solvents, and co-solvents) and processing conditions (e.g., homogenizer type and operating conditions). However, the functional attributes of emulsions can also be tailored after homogenization by manipulating their composition, structure, or physical state. The interfacial properties of lipid droplets can be altered using competitive adsorption or coating methods (such as electrostatic deposition). The physical state of oil droplets can be altered by selecting an oil phase that crystallizes after the emulsion has been formed. The composition of the disperse phase can be altered by mixing different kinds of oil droplets together to induce inter-droplet exchange of oil molecules. The local environment of oil droplets can be altered by embedding them within hydrogel beads. The aggregation state of oil droplets can be controlled by promoting flocculation. These post-homogenization methods can be used to alter functional attributes such as physical stability, rheology, optical properties, chemical degradation, retention/release properties, and/or gastrointestinal fate.

Formulation and Characterization of Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax, Beeswax, Pumpkin Seed Oil, and UV Filters

“…It is very important for NLC to remain physically stable with no or a minimal change in the particle size distribution and PDI throughout the storage period (Piorkowski and McClements, ). A large droplet size may enhance Ostwald ripening (OR) by increasing the droplet size and finally can lead to coalescence and phase separation (Bai and McClements, ; Nazarzadeha et al, ). Conversely, an emulsion can be considered stable if there is no presence of creaming, flocculation, or phase separation during the available time (Bai and McClements, ).…”

“…A large droplet size may enhance Ostwald ripening (OR) by increasing the droplet size and finally can lead to coalescence and phase separation (Bai and McClements, ; Nazarzadeha et al, ). Conversely, an emulsion can be considered stable if there is no presence of creaming, flocculation, or phase separation during the available time (Bai and McClements, ). While an increase in PDI may accelerate in the creaming process that revealed the instability of an emulsion (Trjillo‐Cayado et al, ).…”

“…a, F1 showed smaller particle size than F2 and S7. Based on the finding theory, the smaller the particle size, the smaller chance of the nanoemulsion undergoes OR (Bai and McClements, ). For F1, it increased more in particle size than F2 and S7 in 4 ± 2 °C.…”

Controlling nanoemulsion surface chemistry with poly(2-oxazoline) amphiphiles

“…36,37 Furthermore, chemically robust approaches to append functionality to the surface of emulsions are limited in comparison to conventional nanoparticles. 12,13,35,38,39 Surfactants play Fig. 1 (A) Surfactants dictate the size, charge, and surface chemistry of emulsions.…”

Extending Applications of High-Pressure Homogenization by Using Simultaneous Emulsification and Mixing (SEM)—An Overview

“…However, desired droplet size distributions could also be produced by alternative concepts such as jet homogenizer [35,36] or microfluidic systems [37]. Furthermore, this article will not go into detail on the possibilities of post-homogenization treatment, since these are already discussed in [38].…”