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

Droplet microfluidics technology is recently a highly interesting platform in material fabrication. Droplets can precisely monitor and control entire material fabrication processes and are superior to conventional bulk techniques. Droplet production is controlled by regulating the channel geometry and flow rates of each fluid. The micro-scale size of droplets results in rapid heat and mass-transfer rates. When used as templates, droplets can be used to develop reproducible and scalable microparticles with tailored sizes, shapes and morphologies, which are difficult to obtain using traditional bulk methods. This technology can revolutionize material processing and application platforms. Generally, microparticle preparation methods involve three steps: (1) the formation of micro-droplets using a microfluidics generator; (2) shaping the droplets in micro-channels; and (3) solidifying the droplets to form microparticles. This review discusses the production of microparticles produced by droplet microfluidics according to their morphological categories, which generally determine their physicochemical properties and applications.

https://www.mdpi.com/2072-666X/8/1/22/pdf

Droplet Microfluidics for the Production of Microparticles and Nanoparticles

Basic principles of drug delivery systems - the case of paclitaxel.

Chitosan nanoemulsions as advanced edible coatings for fruits and vegetables: Composition, fabrication and developments in last decade

Hypothesis Surfactants with temperature-sensitive polyoxyethylene (POE) chains are widely used to prepare nanoemulsions by the phase inversion temperature (PIT) method. It is therefore anticipated that surfactants with temperature-sensitive polyoxypropylene (POP) chains could also be used to prepare nanoemulsions by the PIT method. Experiment POP surfactants were synthesized through electrostatic interactions between hydrophilic POP diamines and hydrophobic long-chain fatty acids. The synthesized POP surfactants were used as emulsifiers to prepare n-tetradecane-in-water nanoemulsions by the PIT method. Electrical conductivity measurements were used to determine the PITs of the water/POP surfactant/n-tetradecane systems. The effects of surfactant concentration, NaCl concentration, number of POP units, and degree of unsaturation of hydrocarbon chains on the PIT and the nanoemulsion droplet size were investigated. The droplet size and morphology of the nanoemulsions were characterized by dynamic light scattering and cryogenic transmission electron microscopy, respectively. Findings Nanoemulsions are formed by the PIT method using POP surfactants when the POP chains are short (∼2.5–6.1 POP units). The formation of nanoemulsions with droplet radii of 20–300 nm and spherical morphology occurs because of the temperature-dependent hydration of the short POP chains.

Nanoemulsion formation by the phase inversion temperature method using polyoxypropylene surfactants.

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

Lipid micro and nanoparticles have been extensively investigated as carriers for hydrophobic bioactives in food systems because they can simultaneously increase the dispersibility of these lipophilic substances and help improve their bioavailability. In this study, lipid microparticles of babacu oil and denatured whey protein isolate were produced, and their ability to protect quercetin against degradation was evaluated over 30 days of storage. Additionally, the lipid microparticles were subjected to the typical stress conditions of food processing (presence of sucrose, salt, and thermal stresses), and their physico-chemical stability was monitored. The data show that the babacu microparticles efficiently avoided the oxidation of quercetin because 85% of the initial amount of the flavonoid was preserved after 30 days. The particles were notably stable up to a temperature of 70 °C for 10 minutes at relatively high concentrations of salt and sucrose. The type of stirring (mechanical or magnetic) also strongly affected the stability of the dispersions.

/pdf/effect-of-different-stress-conditions-on-the-stability-of-2s549f76pj.pdf

Effect of different stress conditions on the stability of quercetin-loaded lipid microparticles produced with babacu ( Orbignya speciosa ) oil: evaluation of their potential use in food applications

This study aimed to evaluate the effects of solid lipid particles (SLP) incorporation on the aging process of NaCl-induced gels of soy protein isolate and locust bean gum. The feasibility of incorporating beta-carotene (BC) into emulsion-filled gels (EFGs) was evaluated and the stability of the carotenoid was determined in two systems, SLP and NaCl-induced EFGs. Non-filled gels (NFG) and EFG were characterized to determine their microstructural organization, rheological properties and water holding capacity (WHC) throughout storage. In addition, the amount of BC contained in SLP and EFG was quantified for 30 days. SLP dispersions were stable and retained about 57% of the encapsulated bioactive carotenoid after 30 days. Given the good stability of the SLPs, they were considered suitable for incorporation into the gels and for the production of EFGs. Their incorporation increased the stability of the gel systems. The strength and WHC of NFG systems decreased with aging, while those of EFGs increased. EFGs provided greater protection of encapsulated beta-carotene (about 90% of retention after 30 days of storage) than SLPs, indicating that gelation of the continuous phase is a good strategy to prevent the degradation of encapsulated bioactive carotenoid.

Cold-set NaCl-induced gels of soy protein isolate and locust bean gum: How the ageing process affect their microstructure and the stability of incorporated beta-carotene

Camila Pinheiro Silva Cazado

Papers

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

Effect of different stress conditions on the stability of quercetin-loaded lipid microparticles produced with babacu ( Orbignya speciosa ) oil: evaluation of their potential use in food applications

Cold-set NaCl-induced gels of soy protein isolate and locust bean gum: How the ageing process affect their microstructure and the stability of incorporated beta-carotene