Edible nanoemulsions: fabrication, properties, and functional performance

Abstract

There is increasing interest within the food, beverage and pharmaceutical industries in utilizing edible nanoemulsions to encapsulate, protect and deliver lipophilic functional components, such as oil-soluble flavors, vitamins, preservatives, nutraceuticals, and drugs. There are a number of potential advantages of using nanoemulsions rather than conventional emulsions for this purpose: they can greatly increase the bioavailability of lipophilic substances; they scatter light weakly and so can be incorporated into optically transparent products; they can be used to modulate the product texture; and they have a high stability to particle aggregation and gravitational separation. On the other hand, there may also be some risks associated with the oral ingestion of nanoemulsions, such as their ability to change the biological fate of bioactive components within the gastrointestinal tract and the potential toxicity of some of the components used in their fabrication. This tutorial review provides an overview of the current status of nanoemulsion fabrication, properties, and applications with special emphasis on systems suitable for utilization within the food industry.

Preparation of nanoemulsions by phase inversion temperature (PIT)

“…The main purposes are to encapsulate, protect, and deliver lipophilic components such as drugs, vitamins, food supplements, antioxidants, antimicrobials, pesticides. In general, it is desirable to utilize nanoemulsions with very small droplet sizes, typically < 100 nm, since they have several potential benefits, including increased bioavailability 1,2 , enhanced long-term stability 16 and high optical clarity 17 . These can be explained by the particle properties regarding surface area, kinetic property and optical property which are related to their particle sizes.…”

“…As demonstrated in Table 1, the particles with particle size, typically ≤ 100 nm have a low setting velocity and high Brownian motion. Therefore, the smaller size of the nanoemulsions corresponds to greater stability against gravitational separation and droplet aggregation 16 . The size of the colloidal particles present in the solution determines the appearance of the colloidal dispersion.…”

“…Nanoemulsions can be prepared in a two-step process where macroemulsions is firstly formed and then converted to nanoemulsions in a second step which is typically categorized as high-energy and low-energy emulsification methods 16,[22][23][24] . High-energy methods are based on the use of high energy for bringing down the large droplet size into small nano-size by using specific devices like ultrasound generators or high pressure homogenizers 25 .…”

Emulsion-directed liquid/liquid interfacial fabrication of lanthanide ion-doped block copolymer composite thin films

“…A small amount of emulsion in the lower phase was placed on a 0.1-mm-thick copper disk The formation of the emulsion in the lower phase was attributed to a spontaneous emulsification process related to the "ouzo effect" [34][35][36][37]. to 50 nm that decorated the walls.…”

Emulsified lipids: formulation and control of end-use properties

“…Nanoemulsion delivery systems may also protect the encapsulated bioactives against environmental stresses (e.g. pH, oxygen, and degradation by enzymes), and increase the bioavailability of the encapsulated bioactives because of their small droplet size and high surfaceto-volume ratio (McClements, 2011). Nanoemulsion-based delivery systems are well established in the pharmaceutical domain where they improve the oral bioavailability and biological efficacies of lipophilic drugs (Shah et al, 2010).…”