Food-Grade Nanoemulsions: Formulation, Fabrication, Properties, Performance, Biological Fate, and Potential Toxicity

Abstract

Nanoemulsions fabricated from food-grade ingredients are being increasingly utilized in the food industry to encapsulate, protect, and deliver lipophilic functional components, such as biologically-active lipids (e.g., ω-3 fatty acids, conjugated linoleic acid) and oil-soluble flavors, vitamins, preservatives, and nutraceuticals. The small size of the particles in nanoemulsions (r<100 nm) means that they have a number of potential advantages over conventional emulsions-higher stability to droplet aggregation and gravitational separation, high optical clarity, ability to modulate product texture, and, increased bioavailability of lipophilic components. 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 review article provides an overview of the current status of nanoemulsion formulation, fabrication, properties, applications, biological fate, and potential toxicity with emphasis on systems suitable for utilization within the food and beverage industry.

The use of Brazilian vegetable oils in nanoemulsions: an update on preparation and biological applications

“…Compared to conventional emulsions (2-20 μm), which have a milky white appearance, NE feature a smaller droplet size (< 1μm) which gives them greater kinetic stability and translucent appearance (Tadros, Kessell, 2004;Constantinides, Chaubal, Shorr, 2008;Gupta et al, 2016). Unlike ME, NE requires low concentrations of surfactant (3% to 10%), which makes them less irritating to the stratum corneum (McClements, Rao, 2011). They are used instead of liposomes and vesicles, due to their greater stability, ability to encapsulate lipophilic drugs and ease of preparation on a large scale (Tadros, Kessell, 2004).…”

“…Thus, simple and cheaper strategies to obtain NE are the use of low energy approaches based on the spontaneous emulsification (SE, also called solvent displacement or self-emulsification) of oil droplets in oil-water surfactant by modifying the composition or environment (Sajjadi, 2006;McClements, 2012;Yukuyama et al, 2016). Other low-energy methods occur due to temperature variations during the emulsification process (PIT -Phase Inversion Temperature) (Shinoda, Saito, 1969;Forgiarini et al, 2001;Morales et al, 2003) and maintaining the temperature constant and varying the composition of the system (PIC -Phase Inversion Composition or EPI -Emulsion Phase Inversion) (McClements, Rao, 2011).NE have some advantages in relation to other systems. Compared to conventional emulsions (2-20 μm), which have a milky white appearance, NE feature a smaller droplet size (< 1μm) which gives them greater kinetic stability and translucent appearance (Tadros, Kessell, 2004;Constantinides, Chaubal, Shorr, 2008;Gupta et al, 2016).…”

Is nano safe in foods? Establishing the factors impacting the gastrointestinal fate and toxicity of organic and inorganic food-grade nanoparticles

“…[86][87][88][89] The major advantages of using lipid nanoparticles for these applications is that they can increase the bioavailability and/or functional performance of encapsulated components, they can be designed to be optically transparent (which is desirable for clear foods and beverages), and they can increase the physical stability of the product (since small particles are less susceptible to gravitational separation and aggregation). 84,90 Different types of lipid nanoparticles may be present in foods, including micelles, vesicles, oil droplets, and fat crystals, which vary in their compositions, structures, and dimensions. The diameter of lipid nanoparticles may vary from a few nanometers (surfactant micelles) to a few hundred nanometers (oil droplets or solid lipid nanoparticles).…”

“…90 The GIT fate of lipid nanoparticles depends on their susceptibility to hydrolysis by digestive enzymes, such as lipase and phospholipase. 91 Many types of lipids are hydrolyzed by lipases in the GIT, including TAGs, DAGs, and phospholipids.…”

Optimized conditions to produce water-in-oil-in-water nanoemulsion and spray-dried nanocapsule of red ginseng extract

“…Nanoemulsion system, one of the fast-growing techniques in food and pharmaceutical industries, is utilized to encapsulate, protect and deliver the functional ingredients for health benefits (McClements & Rao, 2011). This technology has been recognized as a prospective delivery system for bio-functional products.…”