Background
Aspergillus niger is one of the most common fungal contaminants of food products, leading to several economic losses on fruit, vegetables and other food products during storage. Over the ...years, several new techniques have been developed to control fungal growth, including photodynamic inactivation, in which excitation of a photosensitizer in the right wavelength leads to ROS production and microbial death.
Results
On this paper, curcumin was used as a natural photosentitizer against A. niger spores. Nanoemulsions were used in order to encapsulated curcumin and increase its water solubility. Results showed that spores inhibition could reach up to 80% after 3 min of irradiation while values for un‐encapsulated curcumin were around 30%.
Conclusion
Results presented show that nanoemulsions could be use to enhance the photoinactivation properties of curcumin, against fungal spores from A. niger. This type of process can be use for food decontamination and preservation.
The current study focused on employing curcumin nanoemulsions (CRNEs) to maintain their quality and prolong shelf life. The three tested CRNE ratios (1.0, 1.5, and 2.00 mg/ml) passed the stability ...test at 40 °C, indicating that all samples were stable for 4 weeks. The pH values ranged from 5.74 to 5.75, the droplet size from 63.05 to 64.55 d nm, and the polydispersity index PDI from 0.457 to 0.494. The spherical shape of (CRNEs) formulations is demonstrated by a TEM micrograph. The zeta potentials of CRNEs ranged between −3.82 and −2.72 mV. The physicochemical parameters of Kareish cheese (KCh) and KCh-CRNEs revealed no significant protein, fat, moisture, and pH variations. Kareish cheese has a poor antioxidant activity of 19.23%, compared to 42.31% in KCh-CRNE3 (2 mg/g). Except for color, the sensory parameters results revealed no significant difference between kareish cheese and KCh-CRNEs. CRNE3 had greater efficacy as an antibacterial agent (MIC values 150 and 250) than natural Curcumin (MIC values 800 and 1000) against Staphylococcus aureus and Bacillus cereus, respectively. In vivo study of KCh-CRNEs against Bacillus cereus, the activity was reduced by (55.5 × 104 cfu/g) in KCh-CRNE3, after 12 days of storage at 4 °C. The antioxidant values were (38.02%) in KCh-CRNE3 at the end of storage with no significant change of protein content or pH for all KCh-CRNEs treatments. The findings suggest that curcumin nanoemulsions can enhance antimicrobial protection in Kareish cheese preservation, extending shelf life, and promoting healthier, more sustainable food products, benefiting both the food industry and public health.
•CRNEs are a promising approach to preserving Kareish cheese while maintaining its quality.•CRNEs enhance the cheese's antioxidant properties.•CRNEs exhibit stronger antibacterial effects compared to natural curcumin.
Summary
The increasing consumer's demand regarding the healthy diet has promoted the research towards novel approaches for preserving minimally processed fruits and vegetables without the necessity ...of using preservatives. Emulsion‐based edible coatings technology is considered a valuable alternative to improve fresh‐cut fruit and vegetable quality. This review discusses some recent advances for the preservation of the quality and safety of fresh‐cut fruits and vegetables with respect to the use of nanoemulsion‐based edible coatings as carrier of functional compounds such as antimicrobial agents, antioxidants and texture enhancers. It focuses especially on the use of natural functional compounds in food preservation as an alternative to synthetic additives. Moreover, the preparation and characterisation of nanoemulsion are also reviewed.
Schematic of fresh‐cut apple coated by nanoemulsion.
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D-limonene is an important constituent of citrus fruits, such as oranges and lemons, and can be extracted as a natural essential oil for controlling the agricultural pests because of ...its antifungal and insecticidal activities. However, the hydrophobicity of D-limonene hinders its full potential and excellent performance. In this research, the effect of emulsifier type, dosage, and emulsification method on the formation and stability of D-limonene-loaded nanoemulsions was investigated by sample appearance, microstructural observations, droplet size measurement, and multiple light scattering analysis. Nanoemulsions prepared with emulsifier (EL-40) exhibited the highest stability, with an appropriate HLB (Hydrophilic Lipophilic Balance) value of 13.5. The stability of nanoemulsions increased at higher emulsifier dosage from 2% to 6%. Also, nanoemulsions fabricated by dropwise addition of aqueous phase (deionized water) into D-limonene as the oil phase premixed with emulsifier were the most stable samples. The optimized formulation of D-limonene-loaded nanoemulsions was determined as: 10 % D-limonene, 6% EL-40, and 84 % deionized water. The quality indicators of this formulation were acceptable in terms of FAO standards. Finally, D-limonene-loaded nanoemulsions could inhibit the growth of various fungal pathogens, including Pyricularia oryzae (rice blast), Rhizoctonia solani (rice sheath blight), Colletortrichum gloeosporiodes (pepper anthracnose), and Phomopsis amygdali (peach shoot blight). This research provides a practical solution for the formulation of stable and effective nanoemulsions containing D-limonene for the control of agricultural crop diseases.
Nanoemulsion-based edible coatings containing oregano essential oil (OEO) as antimicrobial were applied onto low-fat cut cheese to extend its shelf life. Nanoemulsions formulation was 2.0% (w/w) ...sodium alginate, 0.5% (w/w) mandarin fiber, 2.5% (w/w) Tween 80 and 1.5%, 2.0% or 2.5% (w/w) of OEO. Particle size, ζ-potential, apparent viscosity and whiteness index of nanoemulsions were assessed. Water vapor resistance of coatings was evaluated as well as their antimicrobial efficiency against inoculated Staphylococcus aureus and native microbiota growth during refrigerated storage. Headspace gases were measured as an indicator of bacterial activity and sensory alterations such as color and texture of cheese pieces were studied. Coatings with at least 2.0% (w/w) OEO decreased Staphylococcus aureus population from 6.0 to 4.6 log CFU/g after 15 days. Coated-cheese pieces containing 2.5% (w/w) OEO inhibited psychrophilic bacteria or molds and yeasts growth during 6 or 24 days of storage, respectively. Consequently, the atmosphere into the sealed tracks was stabilized and the outward appearance of cheese pieces was preserved. Thus, the present work evidences the feasibility of using mandarin fiber with high nutritional properties and sodium alginate acting as texturizing agents, to form OEO-loaded coatings onto low-fat cut cheese in order to extend its shelf life.
•Nanoemulsions resulted effective as systems to deliver oregano essential oil.•Antimicrobial edible coatings extended the shelf life of low-fat cut cheese.•Coatings controlled cheese native microbiota and Staphylococcus aureus growth.•The qualities of coated cheese were barely affected by oregano essential oil.•Mandarin fiber incorporation can provide nutritional value to coated cheese.
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•Stable crude oil/water nanoemulsions stabilized by biosurfactant are formulated.•The formulated nanoemulsions possess favorable characteristics for EOR applications.•At low shear ...rates, the emulsions showed shearing-thinning behavior.•At high shear rates, the emulsions showed shearing-thickening behavior,•Crude oil is completely recovered from the emulsion in < 1 h upon HCl addition.
The successful utilization of nanoemulsions in several applications would require the formulation of emulsions with excellent characteristics. Ideally, the nanoemulsions should be stabilized using bioemulsifiers, which do not negatively impact the environment throughout their cradle-to-grave lifetime. Thus, crude oil-in-water (O/W) nanoemulsions with exceptional properties were prepared in this study using rhamnolipid biosurfactant as a bioemulsifier. The obtained results reveal that rhamnolipid can produce O/W nanoemulsions with an average droplet size as low as 35.0 ± 6.6 nm. The nanoemulsions also have highly negative zeta potential, low interfacial tension, and long-term kinetic stability. Interestingly, almost all the formulated O/W nanoemulsions using different rhamnolipid dosages and oil/water ratios showed three different flow behaviors (i.e., shear-thinning, Newtonian, and shear-thickening at low, medium, and high shear rates, respectively). Additionally, the nanoemulsion formulated using 50/50 crude oil/water volumetric ratio displayed higher apparent viscosity than the crude oil at elevated temperatures (greater than 63 ⁰C). Furthermore, despite that all the formulated nanoemulsions were extremely stable, they can be easily, completely, and quickly (within ≤ 1 h) switched-off if needed via pH-switching. The results presented herein demonstrate the potential of biosurfactants for enhanced oil recovery (EOR) and other oilfield applications.
Lipid nanoemulsions (NEs), owing to their controllable size (20 to 500 nm), stability and biocompatibility, are now frequently used in various fields, such as food, cosmetics, pharmaceuticals, drug ...delivery, and even as nanoreactors for chemical synthesis. Moreover, being composed of components generally recognized as safe (GRAS), they can be considered as "green" nanoparticles that mimic closely lipoproteins and intracellular lipid droplets. Therefore, they attracted attention as carriers of drugs and fluorescent dyes for both bioimaging and studying the fate of nanoemulsions in cells and small animals. In this review, the composition of dye-loaded NEs, methods for their preparation, and emerging biological applications are described. The design of bright fluorescent NEs with high dye loading and minimal aggregation-caused quenching (ACQ) is focused on. Common issues including dye leakage and NEs stability are discussed, highlighting advanced techniques for their characterization, such as Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS). Attempts to functionalize NEs surface are also discussed. Thereafter, biological applications for bioimaging and single-particle tracking in cells and small animals as well as biomedical applications for photodynamic therapy are described. Finally, challenges and future perspectives of fluorescent NEs are discussed.
The recent focus in the development of novel nanosystems for biomedical applications lays firmly on their interactions with biomolecules. Thermodynamic parameters driving the interaction between ...nanoparticles and proteins provide insights into complex processes at bio/nanointerface. The present work aims to investigate the binding mechanisms and the dominant contributions that determine the adsorption processes during the interactions of a model protein, that is, bovine serum albumin, with a new type of drug delivery systems, Vitamin E/sphingomyelin nanoemulsions, plain and coated with polyethylene glycol, and d‐ɑ‐tocopheryl polyethylene glycol succinate. The binding parameters (binding constant, binding stoichiometry, enthalpy, Gibbs energy, and entropy changes of binding) are evaluated by the isothermal titration calorimetry with a MicroCaliTC200 equipment. The effect of nanoemulsions on the protein stability is examined by measuring the thermodynamic parameters for the protein's unfolding (heat capacity; enthalpy, entropy, and free energy changes) with a NanoDSC (TA Instrument) apparatus. The thermodynamic profile shows for all compositions an entropy‐driven interaction dominated by hydrophobic forces due to the rearrangements/displacement of the surrounding water molecules, while maintaining the native conformation of the protein. All the information acquired by thermodynamic approach may significantly enhance the knowledge with special focus on PEGylated nanoemulsions used for biomedical applications.
Thermodynamic parameters at bio/nano interface emerge as key descriptors for the dominant contributions determining the adsorption processes
•Oregano and clove nanoemulsions were used as antifungals in media and dressings.•The effect of nanoemulsions on the sensory profile of dressings was tested.•Efficacy of essential oil nanoemulsions ...against Z. bailii was demonstrated.•Addition of nanoemulsions to salad dressings prolonged their shelf life.•Sensory panellists accepted the salad dressing with oregano nanoemulsion.
This work aimed to evaluate the in vitro effect of encapsulated oregano and clove essential oils on oil-in-water nanoemulsions against Zygosaccharomyces bailii. The antifungal efficacy of these nanoemulsions and their sensory acceptance were tested in salad dressings. Both essential oils were effective inhibitors against the target yeast, with minimal inhibitory and fungicidal concentrations of 1.75 mg/mL. In the in vitro assay done with the nanoemulsions, no yeast growth was observed for any tested essential oil concentration. In the salad dressings, all the formulations were able to reduce Z. bailii growth compared to the control, and only those samples with 1.95 mg/g of essential oil were capable of inhibiting yeast development after 4 inoculation days. The sensory acceptance of the dressing containing the nanoemulsions was similar to the control dressing in appearance, consistency and colour terms. These results evidence the antifungal activity of oregano and clove nanoemulsions against Z. bailii.
Rationale: Immune checkpoint (ICP) blockade therapy combined with chemotherapy is a promising treatment strategy for tumors. Chemotherapeutic agents usually function inside the tumor cells, while ICP ...inhibitors are efficacious out of the tumor cells. It is desirable to effectively co-deliver an ICP inhibitor and a chemotherapy agent to different sites of a tumor. We have designed an effective drug delivery system to accomplish both objectives. Methods: We designed a Pickering nanoemulsion (PNE) using multi-sensitive nanogels with pH-responsive, hydrophilicity-hydrophobicity switch, and redox-responding properties as an oil/water interfacial stabilizer. The D/HY@PNE was employed for specified spatial delivery of the chemotherapy agent doxorubicin (DOX) and ICP inhibitor HY19991 (HY). We systematically investigated the pH-responsive disassembly of PNE, the release of DOX and HY from D/HY@PNE in the tumor microenvironment, enhanced tumor penetration of DOX, immunogenic cell death (ICD), antitumor efficacy, and the immune response induced by D/HY@PNE in vitro and in vivo. Results: D/HY@PNE disassembled to release the ICP inhibitor HY and DOX-loaded nanogels due to the hydrophilicity-hydrophobicity reversal of nanogels in the acidic tumor microenvironment. Quantitative analysis indicates that D/HY@PNE presents enhanced tumor penetration behavior and effectively induces ICD. The strong immune response induced by D/HY@PNE was due to the efficient synergetic combination of chemotherapy and immunotherapy and resulted in enhanced antitumor efficacy in 4T1 tumor-bearing mice. Conclusion: This novel strategy highlights the promising potential of a universal platform to co-deliver different therapeutic or diagnostic reagents with spatial regulation to improve the anti-tumor effect.
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