Nanoemulsions are a relatively new technology that has found significant use for delivering functional chemicals such as micronutrients, flavorings, bioactive molecules, and antimicrobial agents into food and beverage products. This article focuses on applying nanoemulsions for sustainable food processing and packaging in the food sector.
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What is a Nanoemulsion?
Nanoemulsions (NEs) are non-equilibrium dispersions of at least two immiscible liquids (oil and water) with droplet sizes of 10–100 nm that are kinetically stable. These nanoemulsions have revolutionized the pharmaceutical, healthcare, skincare and food businesses. They have several remarkable properties, including small droplet size, transparency, enhanced surface area, and reduced sensitivity to chemical and physical changes, making them ideal for food formulations.
Components for the Formation of Nanoemulsions
Core-shell architecture may be used to describe nanoemulsions, and it is made up of three phases: an oil phase (lipophilic), an aqueous phase (amphiphilic), and a surfactant (emulsifier/stabilizer) in precise proportions.
The features of the phases and surfactants should be considered when making nanoemulsions. Surfactants must be carefully selected to achieve an ultra-low interfacial tension (<10-3 mN/m) at the oil/water interface, essential for producing nanoemulsions. The physical and chemical parameters of the oil phase influence the development and stability of nanoemulsions.
Approaches for the Preparation of Nanoemulsions
The size of nanoemulsions is determined by the ingredients, operating circumstances, and technique of manufacture. High-energy or low-energy procedures can be used to make nanoemulsions.
Ultrasonication, microfluidization, and high-pressure homogenization are examples of high-energy procedures that use mechanical devices to disturb the oil phase, allowing it to interact with the water phase and create tiny oil droplets.
To make oil-in-water nanoemulsions, most food industries employ high-energy technologies. Nanoemulsions are made by changing the composition or temperature of the oil-water system in low-energy approaches, including phase inversion composition and phase inversion temperature.
Applications of Nanoemulsions in Food Industry
Most bioactive food components are prone to oxidative deterioration and degradation during food processing. Some bioactive have a low solubility yet a fast metabolism, lowering their bioavailability, whereas others are volatile and sensitive to processing conditions. Utilizing nanoemulsions to encapsulate bioactive chemicals in the food matrix can solve these obstacles.
Encapsulating a bioactive chemical protects it from processing conditions and prevents it from degrading for an extended period due to light, pH, temperature, and oxidative conditions encountered during storage.
Nanoemulsions are an effective method for increasing the digestibility of food and controlling the rate of release and absorption of bioactive chemicals in the gastrointestinal system.
Also, the bioavailability of active ingredients, the pharmacological activity of certain chemicals, and the solubility of pharmaceuticals are all improved by nanoemulsions.
Nanoemulsions can encapsulate useful chemicals and active substances, such as nutraceuticals and antioxidants. Additionally, they are beneficial for the controlled release of flavor components in foods.
Nanoemulsion based Food Packaging
Nanoemulsions can be integrated into coatings and films for possible food packaging applications. Foods such as dairy products, meats, fruit and vegetables can be coated with nanoemulsion-based edible nanocoatings containing flavor and coloring components, enzymes, antioxidants, and antimicrobials agents to extend their shelf life. Coatings can also limit gas exchange, moisture and food oxidation.
Commercialization of Nanoemulsion in Food Products
Nanoemulsions have been employed in food by companies like Nestle and Unilever, as well as a few start-ups. For example, Nestle's design aids quick and uniform thawing of frozen foods in the microwave, while Unilever utilizes nanoemulsions in ice creams to reduce fat levels from 16 to 1%.
NanoceuticalsTM Slim Shake Chocolate was developed by RBC Life sciences. It utilizes the NanoClusterTM delivery method, which encapsulates dietary supplements in a nanoscale powder. LivOn Labs has created Lypo-SphericTM Vitamin C, which encapsulates Vitamin C using smart liposomal Nanospheres®.
Future Perspectives and Challenges
Nanoemulsions containing bioactive chemicals and functional food components have significant potential in the food and beverage industries. However, food grade nanoemulsions will find broad application only if their manufacturing costs are commercially viable and they fulfill the food industry's safety regulations.
As a result, enhancing the bioactivity of the encapsulated components is essential for increasing production capacity. Additional research should be conducted to determine the biological events and the risks associated with nanoemulsion-based delivery technologies in food goods and packaging, with the goal of guaranteeing consumer safety.
Continue reading: Synthesizing Uniform Nanoparticles with Nanoemulsion Strategies.
References and Further Reading
Azmi, N., Elgharbawy, A., Motlagh, S., Samsudin, N. and Salleh, H., (2019) Nanoemulsions: Factory for Food, Pharmaceutical and Cosmetics. Processes, 7(9), p.617. Available at: https://www.mdpi.com/2227-9717/7/9/617
Aswathanarayan, J. and Vittal, R., (2019) Nanoemulsions and Their Potential Applications in Food Industry. Frontiers in Sustainable Food Systems, 3. Available at: https://doi.org/10.3389/fsufs.2019.00095
Goindi, S., Kaur, A., Kaur, R., Kalra, A. and Chauhan, P., 2016. Nanoemulsions: an emerging technology in the food industry. Emulsions, pp.651-688. Available at: https://doi.org/10.1016/B978-0-12-804306-6.00019-2