Encapsulating Essential Oils in Food Production

Essential oils encapsulation in nanoemulsions, liposomes, microcapsules, and molecular inclusion complexes may prevent degradation and contamination.

FREMONT, CA: Foods and nutraceuticals, including essential oils (EOs), have become increasingly popular due to a modern lifestyle and consumer interest. Due to their hydrophobic nature, as well as their instability and degradation when exposed to environmental conditions like oxygen, temperature, and light, EOs may not be suitable for use in food or pharmaceuticals. Microcapsules, nanospheres, nanoemulsions, liposomes, and molecular inclusion complexes solve such problems. As a result of their potent antimicrobial agents and excellent activity against pathogenic bacteria, capsulated bioactive EO constituents have also become increasingly important in food packaging due to their excellent antimicrobial properties. EOs can have their biological activities altered by micro or nano encapsulation.

Due to their synergistic effects, EOs are effective antimicrobials, antioxidants, etc. Since these components enable EOs to be introduced and integrated into a wide range of products, such as cosmetics, nutraceuticals, and food products, their industrial applications are limited. In addition to being highly lipophilic and volatile, they are sensitive to environmental conditions like light, oxygen, and temperature. They evaporate easily and are almost insoluble in water. It has become important for researchers to explore how they can extend their application potential.

Importance of encapsulation: Encapsulation is essential to improve the applications of EOs. The system preserves the bio-functional properties of EOs, enhances their stability, provides benevolent masking effects, and provides controlled release of EOs. Studies show that encapsulating peppermint and green tea essential oils improve thermal stability. Various techniques can be used to achieve encapsulation, including chemical, physicomechanical, and physicochemical methods. Depending on the type of coated material, the operational cost, and the application of the encapsulation products, the most feasible encapsulation technique may involve more than one technique. The encapsulation process's efficiency, the encapsulation's yield, payload and loading capability, and the surface loading of the encapsulation are commonly used as indicators of the quality of the encapsulation product.

Scope to research encapsulation: Encapsulation of EOs has been studied for its physical stability and biological activity but not for its volatile constituents. The formulation of the emulsion using energy-intensive techniques such as high-pressure and high-shear homogenization can result in Ostwald ripening, flocculation, or coalescence, altering its physical stability and biological activity. Few studies have reported such changes. Compared to HD oil and nanoemulsions, essential oil exhibits a higher antioxidant activity than nanocapsules and nanoemulsions, and nanocapsules showed the most potent cytotoxic activity against liver cancer cells. EOs were effectively protected by encapsulation against environmental conditions that may lead to oxidation, volatilization, and decreased biological activity by encapsulation. As well as solving the problem of EO hydrophobicity, encapsulation controls EO release. Spray drying and emulsification are the most versatile and commercially available techniques for encapsulating EOs. There was a significant improvement in the antimicrobial, antifungal, antioxidant, antiviral, and insecticidal activity of encapsulated EOs. Food, cosmetics, and pharmaceutics could benefit from encapsulating EOs and fulfill consumer safety concerns. Further studies are necessary to determine whether encapsulation techniques for EOs are compatible with energy-intensive techniques since they may adversely affect the structure-activity relationship of EOs' bioactive components.