Essential oil based nanoemulsions to improve the microbial quality of minimally processed fruits and vegetables: A review.

Application of essential oils as antimicrobial agents against spoilage and pathogenic microorganisms in meat products.

Background High-added value biological compounds (BACs) from herbal and plant sources, such as essential oils (EO), antioxidants and volatile compounds, often exhibit remarkable features, ranging from nutritive and medicinal properties, as well as antimicrobial and antioxidant activities, which can be exploited in the production of functional foods. However, most BACs exhibit low water solubility, strong off-flavors/odors, and are generally unstable and easily degraded under common processing and storage conditions. Encapsulation is a technology that enables the delivery in food systems, the protection, as well as the controlled and targeted release of BACs. Scope and approach The aim of this review is to summarize the most important information for encapsulation of natural extracts using unconventional technologies. Key findings and conclusions Encapsulation is an excellent choice to stabilize BACs, and in particular EOs, and mask their strong flavors and odors. In particular, spray drying is one of the most economic and common encapsulation technologies. However, the challenges of reducing the operating costs, of developing high-throughput processes, of minimizing the use of organic solvents, and of increasing the level of functionality of the encapsulation systems are driving the research towards the implementation of innovative strategies and non-conventional methods, which incorporate the concepts of Green Food Processing.

Innovative technologies for encapsulation of Mediterranean plants extracts

Several essential oils (EO) are efficient inhibitors of foodborne pathogen growth. However, their direct incorporation into food presents technological challenges, because of the possibility of extreme changes to their sensory properties. Such drawbacks can be overcome by encapsulation techniques, such as nanoemulsification. This study produced nanoemulsions encapsulating different amounts of oregano (Origanum vulgare) EO, using the phase inversion temperature method, and their physicochemical stability and antibacterial activity were evaluated. The average droplet diameters of the nanoemulsions were in the range of 35–55 nm, and nanoemulsions containing 5 g EO/100 g nanoemulsion were the most stable over the storage period of 45 days. The nanoemulsions exhibited good antibacterial action demonstrated by the low values in vitro for minimum inhibitory concentration (0.56 and 0.60 mg oregano EO/mL for Staphylococcus aureus and Escherichia coli, respectively, and for minimum bactericidal concentration, 0.90 and 3.32 mg oregano EO/mL for Staphylococcus aureus and Escherichia coli, respectively). The nanodispersions also had a higher antibacterial effect against E. coli than for S. aureus. The incorporation of nanoemulsions in chicken pâte did not change the physicochemical characteristics of the meat product. Therefore, the results obtained indicated that nanoemulsions encapsulating oregano EO are suitable to be incorporated into food formulations, such as chicken pâte, to prevent and control microbial growth and to extend their shelf life.

Nanoemulsions encapsulating oregano essential oil: Production, stability, antibacterial activity and incorporation in chicken pâté

Nanoemulsions present several advantages over conventional emulsions due to the small droplets size they contain: high optical clarity, good physical stability against gravitational separation and droplet aggregation, and enhanced bioavailability of encapsulated substances, which make them suitable for food applications. Depending on desired formulation, preparation method should be selected to optimize droplet size distribution since it strongly affects stability behavior. Systems with droplets diameter smaller than 200 nm and a monomodal distribution usually have a homogeneous structure, that is, a structure with well-distributed droplets that do not show flocs. A structure with these characteristics remains unchanged for long time, up to six months, given the nanoemulsion enhanced stability compared to conventional emulsions with the same formulation.

Nanoemulsions: stability and physical properties

https://repositorium.sdum.uminho.pt/bitstream/1822/42440/1/document_40142_1.pdf

Physico-chemical stability and in vitro digestibility of beta-carotene-loaded lipid nanoparticles of cupuacu butter (Theobroma grandiflorum) produced by the phase inversion temperature (PIT) method

Luis F. P. Marostegan

Papers

Nanoemulsions encapsulating oregano essential oil: Production, stability, antibacterial activity and incorporation in chicken pâté

Physico-chemical stability and in vitro digestibility of beta-carotene-loaded lipid nanoparticles of cupuacu butter (Theobroma grandiflorum) produced by the phase inversion temperature (PIT) method