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

Preparation of chitosan quaternary ammonium salt/pectin antifogging and antibacterial composite film loaded with riboflavin and its application in rape preservation

In this study, riboflavin (RIB) was incorporated into a chitosan quaternary ammonium salt/pectin (HACC/PEC) matrix to produce a composite film with excellent antifogging properties and antibacterial activity. The incorporation of RIB significantly enhanced the mechanical properties (The TS and EAB of HP4-0.2 were 32.09 MPa and 107.1 %), ultraviolet blocking performance, thermal stability and antibacterial characteristics of the film. Riboflavin effectively reduced the water contact angle, enhancing its antifogging performance and preventing water vapor from condensing on the product's surface. The HP4-0.2 film with RIB resulted the shelf life of rape to 11 d at 4 °C. The film effectively preserved the quality of rape during storage, which reduced the total plate count and minimized the degradation of chlorophyll caused by ultraviolet rays. This study introduced a new idea for food antifogging and antibacterial packaging, establishing a foundation for research into multifunctional antifogging packaging.

Ultrasonic-assisted preparation of rose oil nanoemulsion: Characterization, anti-Escherichia coli activity, and its application in cucumber juice

In this study, six rose oil nanoemulsions (RONs) were prepared under different ultrasonic power preparation conditions (65w, 91w, 97.5w, 130w, 162.5w, and 195w), naming RON-65w, RON-91w, RON-97.5w, RON-130w, RON-162.5w, RON-195w, respectively. The particle size, and zeta potential revealed that the mean particle size of RONs decreased with the rising of ultrasonic power when RONs were freshly prepared. RONs had storage stability for at least 30 days, and the particle size variations of RON-65w and RON-97.5w were smaller than other RONs. Time-killing assay, minimum inhibitory concentration (MIC), and growth curve analysis revealed that RONs exhibited higher antibacterial activities against Escherichia coli than rose oil (RO). Scanning electron microscopy and bacterial membrane integrity analysis revealed that RO and RONs exerted their antibacterial effect by increasing the permeability of bacterial cells, and the leakage of nucleic acids and protein caused by RONs were higher than RO (p < 0.05). Compared with MIC assay, RON-65w and RON-97.5w exhibited significantly higher antibacterial activities than other RONs in growth curve analysis, and RON-65w led to highest leakage of nucleic acids and protein among all RONs in bacterial membrane integrity analysis (p < 0.05). Thus, the effect of ultrasonic power on antibacterial activity of RONs was more obvious under agitated conditions than static experimental conditions. The results of application experiment indicated that RON-97.5w displayed greater inhibition ability against E.coli than RO in cucumber juice. Based on the results of this study, rose oil nanoemulsions can be applied as natural preservatives in liquid foods to prevent bacteria contamination.

Bioactive chitosan based coating incorporated with essential oil to inactivate foodborne pathogen microorganisms and improve quality parameters of beef burger

The aim of this study is to assess the impacts of chitosan (CH) coating with oregano essential oil (OEO) and thyme essential oil (TEO) (0.5%-1.0%; v/w) on the foodborne pathogens and physicochemical parameters of beef burger during refrigerated storage. Preliminary experiment (in vitro) demonstrated that 0.5% OEO and TEO were inhibited all or some of S. aureus, S. Typhimurium, and E. coli O157:H7. On day 30, the E. coli O157:H7 of burger coated with CH + OEO and TEO (1%; w/v) declined by 4 and 5 log10 CFU g-1, respectively, S. Typhimurium and S. aureus decreases (4,5-6 log10 CFU g-1) when compared to the control sample. The quality parameters of beef burger were also enhanced after the coating treatment of CH and essential oils (EOs), including pH value, TBARS, and TVB-N in burger during storage (4 °C/30 d). Besides, CH + EOs coating also reduced the deterioration of the sensory attributes of beef burger, including color, odor, and overall acceptability. The chitosan coatings with EOs have superior mechanical qualities than the control sample, also, the structure of the films was evaluated by SEM. In conclusion, CH coating with EOs (OEO, ETO; 1%) regarded as a successful strategy to improve the quality and prolong the shelf life of beef burger.

Nanoencapsulation of Ocimum basilicum L. and Satureja montana L. Essential Oil Mixtures: Enhanced Antimicrobial and Antioxidant Activity

Background/Objectives: Essential oils (EOs) represent a natural alternative to chemical additives due to their biological activity. This study evaluated the antimicrobial and antioxidant activities of basil and winter savory EO mixtures, their interactions, and the biological potential of chitosan-based nano-encapsulated EO mixtures. Methods: Mixtures of basil and winter savory EOs (ratios 1:1, 2:1, 4:1, 8:1, and 16:1) were analyzed for chemical composition via GC-MS. Antimicrobial activity was assessed using minimal inhibition (MIC) and bactericidal (MBC) concentration assays, and interactions were quantified with fractional inhibitory concentration indices (FICIs). Antioxidant activity was evaluated using the DPPH assay, with combination indices used to interpret interaction effects. Chitosan-based nanoparticles were made with the selected oil mixture (2:1), after which characterization and biological activity were performed. Results: The EO mixture with 2:1 ratio exhibited the strongest joint activity, with synergistic or additive effect against four out of six analyzed microorganisms. Antioxidant activity improved with higher basil proportions, with the 16:1 ratio achieving the lowest EC50 value of 0.052 mg/mL after 120 min and demonstrating synergistic effects at all tested ratios. Higher basil EO content also masked the strong odor of winter savory EO. The biological activity of chitosan-based nanoparticles was increased by encapsulation of the EO mixture (2:1), with an encapsulation efficiency of 75.39%. Conclusions: The EO mixture (2:1) showed best antimicrobial efficacy, with synergistic or additive effects. The nano-encapsulated mixture showed good biological potential with effective and complete odor neutralization. These results indicate the potential of basil and winter savory essential oil mixtures for sustainable food preservation applications.

Sulfonated cellulose nanocrystalline- and pea protein isolate-mixture stabilizes the citral nanoemulsion to maintain its functional activity for effectively preserving fruits

The instability of citral greatly limits its application in food field. This study aimed to develop a safe and green emulsifier-stabilized nanoemulsion (NE) to encapsulate citral for exerting its activities. A series of NEs were prepared using varying proportions (1:2 and 1:3) of sulfonated cellulose nanocrystalline- (CNC-C) and pea protein isolate- (PPI) mixture as emulsifier to encapsulate citral with different content (1 %, 2 %, and 3 %), and their stability, antioxidant and antibacterial activities were evaluated to identify the optimal system. When CNC-C and PPI proportion was 1:3 and citral content was 2 % (CC1-P3-C2), the obtained CC1-P3-C2 incorporated into pectin achieved the excellent preservation effect on kiwifruits and blueberries. It was attributed to the stability and functional activities of CC1-P3-C2. On the one hand, after storage (25 d) or at pH 11 or 100 mM NaCl, its size and polydispersity index were still within acceptance level (<300 nm and 0.3). On the other hand, it showed good antioxidant and antibacterial activities against Escherichia coli, Staphylococcus aureus, Botrytis cinerea, and Botryosphaeria dothidea, which was due to its high encapsulation efficiency (96.78 %). Therefore, CC1-P3-C2 showed a great application potential in fruit preservation, which also provided a feasible strategy to design stable citral NEs.

Comparative Study of Crucial Properties of Packaging Based on Polylactide and Selected Essential Oils

In order to establish the differences in packaging containing various essential oils, polylactide (PLA)-based polymeric films incorporating poly(ethylene glycol) (PEG), clove (C), grapefruit (G), rosemary (R), and tea tree (T) essential oils were obtained and subsequently analyzed. In addition to examining structure and morphology, the polymer films underwent analyses that are particularly important with regard to contact with food. Mechanical and antioxidant properties, water vapor transmission rate (WVTR), and analysis of barrier properties against ultraviolet (UV) radiation, as well as the migration of ingredients into food simulants such as 10% v/v solutions of ethanol, 3% w/v acetic acid solution, and isooctane, were among the critical studies conducted. A comparison of the properties of the obtained materials allowed us to establish that the incorporation of essential oils significantly increases elongation at break and enhances UV barrier properties. In the case of materials containing clove oil and tea tree oil, a reduction in WVTR of about 1 g/m2/h was observed. The migration of the ingredients present in the films filled with clove oil, grapefruit oil, and tea tree oil into the acetic acid solution did not exceed 10 mg/kg, which is an acceptable value according to the European Union restrictions. Taking into account all of the studied properties, it should be stressed that the most promising packaging material is the film filled with clove oil.

Essential Oils as Alternative Green Broad-Spectrum Biocides

Natural compounds from plants represent suitable options to replace synthetic biocides when employed against microorganisms in various applications. Essential oils (EOs) have attracted increased interest due to their biocompatible and rather innocuous nature, and complex biological activity (fungicide, biocide and anti-inflammatory, antioxidant, immunomodulatory action, etc.). EOs are complex mixtures of derived metabolites with high volatility obtained from various vegetal parts and employed to a great extent in different healthcare (natural cures, nutrition, phyto- and aromatherapy, spices) and cosmetics applications (perfumery, personal and beauty care), as well as in cleaning products, agriculture and pest control, food conservation and active packaging, or even for restauration and preservation of cultural artifacts. EOs can act in synergy with other compounds, organic and synthetic as well, when employed in different complex formulations. This review will illustrate the employment of EOs in different applications based on some of the most recent reports in a systematic and comprehensive, though not exhaustive, manner. Some critical assessments will also be included, as well as some perspectives in this regard.

Advances in antimicrobial techniques to reduce postharvest loss of fresh fruit by microbial reduction

This review will provide new ideas for preserving fruits and decreasing fruit waste. This review outlines and evaluates research concerning postharvest fruit preservation employing antimicrobial strategies, which involve the integration of biological control alongside physical or chemical methods. The concurrent deployment of two or three of these techniques, particularly biological approaches, has demonstrated enhanced and synergistic antimicrobial outcomes in practical scenarios.

Essential oil-nanoemulsion based edible coating: Innovative sustainable preservation method for fresh/fresh-cut fruits and vegetables

Utilizing plant-based sources for the preservation of fresh and fresh-cut fruits and vegetables offers a natural and chemical-free method. However, the inherent instability of plant bioactive compounds underscores the necessity for encapsulation techniques. Essential oil-based nanoemulsions (EO-NEs) stand out among food additives due to their distinctive antibacterial and antioxidant properties. This review delves into recent advancements in the application of EO-NEs as edible coatings for fresh and fresh-cut produce. It examines the efficacy of EO-NEs in enhancing the preservation of fruits and vegetables by harnessing their bioactive compounds for antibacterial, antifungal, and antioxidant activities. Additionally, the review accentuates the efficacy of EO-NEs in inhibiting biofilm formation on fruits and vegetables. It reveals that coatings derived from plant-source nanoemulsions exhibit exceptional mechanical, optical, and microstructural qualities, as well as superior water barrier properties. In contrast to conventional emulsions, nanocoatings facilitate the gradual and controlled release of antimicrobial and antioxidant compounds during food storage. This feature enhances bioactivity, extends shelf life, and enhances the nutritional profile of products. By preserving and protecting shelf stability, EO-NEs contribute to the maintenance of vegetable freshness. Nonetheless, ensuring their commercial viability necessitates additional research into the toxicity of EO-based nanoemulsions.

Potential and application of tandem mass spectrometry (MS/MS) in the analysis and identification of novel bacteriocins: a review

Bacteriocins are antimicrobial peptides synthesised ribosomally by Gram-positive or Gram-negative bacteria to gain a competitive advantage. The majority of bacteriocins are derived from Gram-positive bacteria, with lactic acid bacteria being the most common source. Because they are considered ‘natural’, there is currently significant development of bacteriocins for application as food preservative agents. As a preservative agent, bacteriocin activity is highly dependent on purity, down to the amino acid profile and sequence. Therefore, bacteriocin identification is important. Currently, MS is a cutting-edge tool in bacteriocin identification. This method has high selectivity, sensitivity and resolution. To the best of our knowledge, systematic reviews focusing on the application of MS for bacteriocin identification are currently limited. In light of this, the objective of this study is to provide a comprehensive review and summary of MS technologies in bacteriocin research, with a particular focus on the discovery and characterisation of novel sources of bacteriocin. Additionally, studies related to the discovery of bacteriocins from various sources, their role as antimicrobial agents, and their synthesis are emphasised. Thus, this study presents a comprehensive analysis of the advantages, limitations, and future perspectives of the methods employed.

Understanding the potential of fresh produce as vehicles of Salmonella enterica

This chapter presents an overview of Salmonella enterica as a contaminant in fresh produce, exploring outbreaks and recalls linked to them. It also provides information on potential sources of S. enterica contamination throughout the entire production chain of these products and presents food safety tools and new approaches for controlling this pathogen. S. enterica is recognized worldwide as a pathogen responsible for foodborne outbreaks, and there has been an increase in reported cases of salmonellosis linked to fresh produce. These products are susceptible to contamination throughout various stages of the farm-to-fork process. The potential sources of contamination are present from pre-harvest and harvest stages (e.g., soil, blossoms, seeds, irrigation water and gray/blackwater, wild and domestic animals/organic fertilizers, and distinctive traits of the plant) to post-harvest stages (e.g., processing, packaging, storage/retail, and preparing for consumption). Thus, controlling S. enterica contamination is extremely important for ensuring the safe consumption of fresh produce. However, obtaining practical, efficient, low-cost, and sustainable solutions that ensure the products' sensorial, nutritional, and food quality is still a challenge. As an alternative to conventional methods, recent studies report the use of new technologies, such as neutral, acidic or low chlorine electrolyzed oxidizing water, ultraviolet light, ultrasound, microemulsion of essential oils, cold plasma, irradiation, bacteriophages, and other methods, which can be used alone or in combination with the conventional ones. Therefore, understanding the main sources of S. enterica contamination in fresh produce and the effective approach for controlling this pathogen is crucial to reducing future outbreaks.

Preparation of sanguinarine/glabridin loaded antifungal double-layer nanoemulsion edible coating using arabic gum/WPI for forest frog's oviduct oil preservation

Forest frog's oviduct oil (FFOO) is highly susceptible to microbial spoilage during storage, which causes serious safety concerns and economic losses. However, little information is available regarding the preservation of it up to now. The aim of this research is to understand the dominant microbial community of FFOO spoilage, and based on this, develop a kind of edible nanoemulsion coating for preserving FFOO. Microbial metagenomic analysis indicated that the Aspergillus genus increased significantly during storage. In the present study, gum arabic and whey protein isolate were chosen as the coating matrix, the natural compounds sanguinarine and glabridin were selected as antimicrobial agents to prepare double-layer nanoemulsion edible coating. When the ratio of sanguinarine and glabridin in the nanoemulsion was 1:3, it exhibited strongest storage stability and antifungal activity. The mycelial inhibition rate of 1:3 nanoemulsion against dominant microbial community (Aspergillus niger and Aspergillus glaucus) reached 88.89 ± 1.37 % and 89.68 ± 1.37 %, respectively. The experimental results indicated that the edible nanoemulsion coating not only had outstanding antifungal activity, but also had excellent fresh-keeping effect on FFOO. This nanoemulsion coating could be a promising and potential candidate for food preservation.

Research progress on natural preservatives of meat and meat products: classifications, mechanisms and applications

Meat and meat products are highly susceptible to contamination by microorganisms and foodborne pathogens, which cause serious economic losses and health hazards. The large consumption and waste of meat and meat products means that there is a need for safe and effective preservation methods. Furthermore, toxicological aspects of chemical preservation techniques related to major health problems have sparked controversies and have prompted consumers and producers to turn to natural preservatives. Consequently, natural preservatives are being increasingly used to ensure the safety and quality of meat products as a result of customer preferences and biological efficacy. However, information on the current status of these preservatives is scattered and a comprehensive review is lacking. Here, we review current knowledge on the classification, mechanisms of natural preservatives and their applications in the preservation of meat and meat products, and also discuss the potential of natural preservatives to improve the safety of meat and meat products. The current status and the current research gaps in the extraction, application and controlled-release of natural antibacterial agents for meat preservation are also discussed in detail. This review may be useful to the development of efficient food preservation techniques in the meat industry. © 2024 Society of Chemical Industry.

Development of Functional Composite Edible Films or Coatings for Fruits Preservation with Addition of Pomace Oil-Based Nanoemulsion for Enhanced Barrier Properties and Caffeine for Enhanced Antioxidant Activity

The aim of this study was to develop functional composite edible films or coatings for fruit preservation by the addition of bioactive components in combinations that have not yet been thoroughly studied, according to the relevant literature. Edible films were initially composed of (i) chitosan (CH), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio), and (ii) hydroxypropyl methylcellulose (HPMC), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio). The bioactive components incorporated (5, 10 and 15% v/v) were as follows: (i) pomace oil-based nanoemulsion (NE) aiming to enhance barrier properties, and (ii) caffeine (C), aiming to enhance the antioxidant activity of films, respectively. Indeed, NE addition led to very high barrier properties (low oxygen and water vapor permeability), increased flexibility and reduced color. Furthermore, the contribution of these coatings to fresh strawberries' preservation under cold storage was investigated, with very promising results concerning weight loss, color difference, and preservation of fruit moisture and quantity of O2 and CO2 inside the packages. Additionally, C addition led to very high antioxidant activity, reduced color and improved barrier properties. Finally, the contribution of these coatings to avocado's preservation under cold storage was investigated, with very encouraging results for color difference, hardness and peroxide value of the fruit samples.

Dynamics of eugenol included in β-cyclodextrin by nuclear magnetic resonance and molecular simulations

Eugenol-β-cyclodextrin complex has been widely used because of the enhanced stability and conservation of the properties of eugenol. Applications in food and health sciences have been shown previously, which makes this complex an excellent model to understand and develop methodologies for the analysis and prediction of physical properties. In this work, the dynamics of eugenol incorporated into β-cyclodextrin are presented, using NMR relaxation rates, and the predictive capabilities of molecular dynamics simulations are discussed. Results show a hindered rotation of eugenol around the principal inertial axes when located inside β-cyclodextrin. Moreover, a translational movement of the whole complex is demonstrated.

Ultrasound-Assisted Nanoemulsion Loaded with Optimized Antibacterial Essential Oil Blend: A New Approach against Escherichia coli, Staphylococcus aureus, and Salmonella Enteritidis in Trout (Oncorhynchus mykiss) Fillets

This study aimed to obtain and characterize an oil-in-water nanoemulsion (NE) loaded with an in vitro optimized bactericidal essential oil blend of 50% oregano, 40% thyme, and 10% lemongrass and to evaluate its potential at three different concentrations (0.5%, 1%, and 2%) in the inactivation of Escherichia coli, Staphylococcus aureus, and Salmonella enterica serotype Enteritidis inoculated in rainbow trout fillets stored at 4 °C for 9 days. Regarding the NE, the nanometric size (<100 nm) with low polydispersion (0.17 ± 0.02) was successfully obtained through ultrasound at 2.09 W/cm2. Considering the three concentrations used, S. Enteritidis was the most susceptible. On the other hand, comparing the concentrations used, the NE at 2% showed better activity, reducing S. Enteritidis, E. coli, and S. aureus by 0.33, 0.20, and 0.73 log CFU/g, respectively, in the trout fillets. Thus, this data indicates that this is a promising eco-friendly alternative to produce safe fish for consumption and reduce public health risks.

Effect of Gamma Irradiation on Pathogenic Staphylococcus aureus in Packaged Ready-to-Eat Salads Treated with Biological Extracts

Providing pathogen-free ready-to-eat (RTE) salads is critical for all consumers, especially individuals with weakened immunity. In this study, the efficacy of γ-irradiation on Staphylococcus aureus (S. aureus) in freshly packaged salads (4.24 log CFU/g) treated with essential oil (EO) and myrtle juice during 10 days of storage and their impact on organoleptic properties were investigated. EO was extracted by hydrodistillation and the chemical composition was analyzed by gas chromatography with Flame Ionization Detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS). Myrtle juice was prepared from fresh fruits. The cytotoxic effects of Thymus capitatus (T. capitatus) EO against a normal human umbilical vein endothelial cell (HUVEC) were assessed. GC/FID and GC-MS analysis of the thyme EO revealed the presence of 13 compounds, including carvacrol (79.55%) and p-cymene (7.93%) as major components. The EO was found to be noncytotoxic, with concentrations lower than 0.16 µL/mL. A reduction of more than 3 log CFU/g and a total inactivation of S. aureus were achieved with the combination of gamma irradiation at 0.5 kGy with myrtle juice at 6 µL/mL and EO at 0.08 µL/mL, respectively. The treatment of fresh RTE salads with thyme and myrtle juice was evaluated as acceptable by the sensory panel. The combined effect showed a synergistic potential on the inactivation of S. aureus.

Promising Larvicidal Effects of Nanoliposomes Containing Carvone and Mentha spicata and Tanacetum balsamita Essential Oils Against Anopheles stephensi

PURPOSE

The use of synthetic pesticides to control the spread of mosquito-borne diseases has caused environmental pollution and insecticide resistance in mosquitoes. Developments of new green insecticides have thus received more attention to overcome these problems.

METHODS

Nanoliposomes containing carvone and essential oils were first prepared. The nanoliposome physicochemical characteristics (particle size, morphology, and successful loading) were then evaluated by Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), and the Attenuated Total Reflection-Fourier Transform InfraRed (ATR-FTIR) analyses. Larvicidal effects of carvone, Mentha spicata, and Tanacetum balsamita essential oils were investigated against the main malaria vector, Anopheles stephensi, in non-formulated and nanoformulated states.

RESULTS

The larvicidal effects of nanoformulated states were significantly more potent (7.2 folds, 3.5 folds, and 8 folds) than non-formulated states. Nanoliposomes containing M. spicata and T. balsamita essential oils with particle sizes of 175 ± 8 and 184 ± 5 nm showed the best efficacies (LC50 values = 9.74 and 9.36 μg/mL).

CONCLUSION

The prepared samples could be used as new green potent larvicides against An stephensi mosquito in further field trials. It is also recommended to investigate their efficacies against other mosquitoes.

Comparison of Emulsion Stabilizers: Application for the Enhancement of the Bioactivity of Lemongrass Essential Oil

Recent focus on cellulose nanomaterials, particularly biodegradable and biocompatible cellulose nanocrystals (CNCs), has prompted their use as emulsion stabilizers. CNCs, when combined with salt, demonstrate enhanced emulsion stabilization. This study explored three emulsion stabilizers: Tween 80, soybean CNCs with salt (salted CNCs), and a combination of salted CNCs with Tween 80. Soybean CNCs, derived from soybean stover, were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Antifungal testing against Aspergillus flavus revealed increased bioactivity in all lemongrass essential oil (EO)-loaded emulsions compared to pure essential oil. In addition, all three emulsions exhibited a slight reduction in antifungal activity after 30 days of room temperature storage. The release experiment revealed that the EO-loaded nanoemulsion exhibited a slow-release profile. The nanoemulsion stabilized by salted CNCs and Tween 80 exhibited significantly lower release rates when compared to the nanoemulsion stabilized solely by Tween 80, attributed to the gel network formed by salted CNCs. The findings of this study highlight the efficacy of cellulose nanocrystals procured from soybean byproducts in conjunction with synthetic surfactants to create nanoencapsulated essential oils, resulting in improved antimicrobial efficacy and the achievement of sustained release properties.

Development of biobased multifunctional films incorporated with essential oils@polydopamine nanocapsules for food preservation applications

A novel multifunctional soy protein isolate-carboxymethyl cellulose (SPI-CMC) based nanocomposite film was successfully prepared by introducing the polydopamine encapsulated essential oils (EOs@PDA) nanocapsules for food packaging. The EOs@PDA nanocapsules possessed smooth spherical morphology with good dispersion, and the particle size was about 283 nm. The influence of EOs@PDA nanocapsules on the physical, chemical and biological properties of EOs@PDA/SPI-CMC nanocomposite film was investigated. The EOs@PDA nanocapsules were crosslinked with SPI-CMC matrix and distributed uniformly in the matrix. The nanocomposite film with 1 wt% nanocapsules (EP/S-C) also showed excellent antioxidant activity (66.6 ± 0.3 % on DPPH and 98.6 ± 0.1 % on ABTS), superior UV-blocking properties (100 %), advanced antibacterial ability against E. coli and S. aureus, favorable biodegradability (>90 %) and relatively low In vitro cytotoxicity. Also, the EP/S-C nanocomposite film displayed potential to extend the shelf life of fresh cut apple slices (>24 h), perishable cherry tomatoes and blueberries (>6 days). The results suggested that the EOs@PDA/SPI-CMC nanocomposite film had a great possibility in the field of biodegradable and antimicrobial materials for food packaging.

Citrus essential oils - Based nano-emulsions: Functional properties and potential applications

Citrus essential oils are natural products with various bioactive properties (e.g., antimicrobial, antioxidant, and antimutagenic activities), that are generally recognized as safe (GRAS) by Food and Drug Administration (FDA) to be used as flavorings and food additives. Nonetheless, due to their high volatility, low solubility in water, low thermal stability, susceptibility to oxidation, and strong flavor, their applications in the food industry are limited. Nanotechnology allows the incorporation of citrus essential oils into nano-emulsion systems, thus protecting them from the deterioration caused by external factors and maintaining or even improving their functional properties. This study aims to summarize the antioxidant, antimicrobial, and antimutagenic effects of the nano-emulsions based on essential oils from citrus peels with emphasis on their mechanisms of action and potential applications in, e.g., foods, pharmaceuticals, and cosmetics.

Modulating the glycemic response of starch-based foods using organic nanomaterials: strategies and opportunities

Traditionally, diverse natural bioactive compounds (polyphenols, proteins, fatty acids, dietary fibers) are used as inhibitors of starch digestive enzymes for lowering glycemic index (GI) and preventing type 2 diabetes mellitus (T2DM). In recent years, organic nanomaterials (ONMs) have drawn a great attention because of their ability to overcome the stability and solubility issues of bioactive. This review aimed to elucidate the implications of ONMs in lowering GI and as encapsulating agents of enzymes inhibitors. The major ONMs are presented. The mechanisms underlying the inhibition of enzymes, the stability within the gastrointestinal tract (GIT) and safety of ONMs are also provided. As a result of encapsulation of bioactive in ONMs, a more pronounced inhibition of enzymes was observed compared to un-encapsulated bioactive. More importantly, the lower the size of ONMs, the higher their inhibitory effects due to facile binding with enzymes. Additionally, in vivo studies exhibited the potentiality of ONMs for protection and sustained release of insulin for GI management. Overall, regulating the GI using ONMs could be a safe, robust and viable alternative compared to synthetic drugs (acarbose and voglibose) and un-encapsulated bioactive. Future researches should prioritize ONMs in real food products and evaluate their safety on a case-by-case basis.

The regulation of carbon dioxide on food microorganisms: A review

This review presents a survey of two extremely important technologies about CO2 with the effectiveness of controlling microorganisms - atmospheric pressure CO2-based modified atmosphere packaging (MAP) and high pressure CO2 non-thermal pasteurization (HPCD). CO2-based MAP is effectively in delaying the lag and logarithmic phases of microorganisms by replacing the surrounding air, while HPCD achieved sterilization by subjecting food to either subcritical or supercritical CO2 for some time in a continuous, batch or semi-batch way. In addition to the advantages of healthy, eco-friendly, quality-preserving, effective characteristic, some challenges such as the high drip loss and packaging collapse associated with higher concentration of CO2, the fuzzy mechanisms of oxidative stress, the unproven specific metabolic pathways and biomarkers, etc., in CO2-based MAP, and the unavoidable extraction of bioactive compounds, the challenging application in solid foods with higher efficiency, the difficult balance between optimal sterilization and optimal food quality, etc., in HPCD still need more efforts to overcome. The action mechanism of CO2 on microorganisms, researches in recent years, problems and future perspectives are summarized. When dissolved in solution medium or cellular fluids, CO2 can form carbonic acid (H2CO3), and H2CO3 can further dissociate into bicarbonate ions (HCO3-), carbonate (CO32-) and hydrogen cations (H+) ionic species following series equilibria. The action mode of CO2 on microorganisms may be relevant to changes in intracellular pH, alteration of proteins, enzyme structure and function, alteration of cell membrane function and fluidity, and so on. Nevertheless, the effects of CO2 on microbial biofilms, energy metabolism, protein and gene expression also need to be explored more extensively and deeply to further understand the action mechanism of CO2 on microorganisms.

Microencapsulation via Spray-Drying of Geraniol-Loaded Emulsions Stabilized by Marine Exopolysaccharide for Enhanced Antimicrobial Activity

The current study investigates the formation of microencapsulated geraniol powder, with the exopolysaccharide EPS-K1B3 produced by Halomonas caseinilytica K1, as wall material, using spray-drying. Evaluation of the antimicrobial activity of the functional emulsions, prepared at either pH 5 or pH 7, was carried out against Gram-positive (Listeria innocua (ATCC 33090)) and Gram-negative (Escherichia coli (DSM682)) bacterial strains. Results showed prolonged antimicrobial efficacy until 30 days of incubation for geraniol microcapsules compared to wet geraniol emulsions, which could confirm the ability of the spray-drying process to protect encapsulated geraniol for a longer period. The highest antimicrobial efficacy of geraniol microcapsules was observed against L. innocua at pH 5. Therefore, the influence of pH on the functional property of geraniol microcapsules could be highlighted beside the targeted bacterial strain.

Differentiating True and False Cinnamon: Exploring Multiple Approaches for Discrimination

This study presents a comprehensive literature review that investigates the distinctions between true and false cinnamon. Given the intricate compositions of essential oils (EOs), various discrimination approaches were explored to ensure quality, safety, and authenticity, thereby establishing consumer confidence. Through the utilization of physical-chemical and instrumental analyses, the purity of EOs was evaluated via qualitative and quantitative assessments, enabling the identification of constituents or compounds within the oils. Consequently, a diverse array of techniques has been documented, encompassing organoleptic, physical, chemical, and instrumental methodologies, such as spectroscopic and chromatographic methods. Electronic noses (e-noses) exhibit significant potential for identifying cinnamon adulteration, presenting a rapid, non-destructive, and cost-effective approach. Leveraging their capability to detect and analyze volatile organic compound (VOC) profiles, e-noses can contribute to ensuring authenticity and quality in the food and fragrance industries. Continued research and development efforts in this domain will assuredly augment the capacities of this promising avenue, which is the utilization of Artificial Intelligence (AI) and Machine Learning (ML) algorithms in conjunction with spectroscopic data to combat cinnamon adulteration.

Edible and essential oils nanoparticles in food: a review on the production, characterization, application, stability, and market scenario

The application of oils in the food industry is challenging, owing to their inherent factors such as oxidation. Therefore, new technologies, such as nanoencapsulation, are being developed. Among the nanoencapsulated oils, essential oils (EO) and edible oils stand out for their high consumer demand. This review analyzes the production, characterization, stability, and market scenario of edible and EO nanoparticles applied in foods. Homogenization was found to be the most common technique for producing oil nanoparticles. Different encapsulants were used, and Tween 80 was the main emulsifier. Approximately 80% of the nanoparticles were smaller than 200 nm, and the polydispersibility index and zeta potential values were satisfactory, mainly for nanoparticles containing EO, whereas encapsulation efficiency varied based on the technique and the type of oil used. Oil nanoparticles were mainly applied on meat products. The temperatures and times used in the stability tests of foods containing oil nanoparticles varied depending on the food matrix, especially in microbiological and physicochemical analyses. Only one product with nanoencapsulated oil in its composition was found in the market. Oil nanoparticles have great potential in the development of innovative, economically viable, and sustainable techniques for producing new food products that are high in nutrition value.

Effect of Edible Coatings of Cassava Starch Incorporated with Clove and Cinnamon Essential Oils on the Shelf Life of Papaya

Applying edible coatings added with plant essential oils is a strategy used to delay ripening processes in climacteric fruits such as papaya. Formulations comprising 3% or 4% cassava starch (w/v), added with clove or cinnamon essential oils (2 mL/L), were tested for microbial inhibition (in vitro) purposes. Moreover, these fruits' physicochemical and microbiological aspects were assessed at 25 °C, for 12 days. Slight variations in pH and Brix values were observed during storage. On the other hand, there were no significant variations in carotenoid contents over storage time. The papaya fruits' coating contributed to reducing their weight loss from 40.66% (uncoated sample) to 24.10% on the 12th storage day, as well as delayed changes often observed during the ripening process. The 4% cassava starch coatings added with essential oils were more efficient in reducing microbiological levels. The herein proposed treatments reduced aerobic mesophilic bacteria, as well as molds and yeast counts, by 1.48 and 1.95 log CFU/g, on average, respectively, in comparison to the control sample. The assessed microorganism counts were higher in the uncoated sample than in the coated papaya fruits, after 12 days of storage. Thus, the tested coatings can potentially delay the emergence of post-harvest changes; consequently, they can help improve the quality of papaya fruits and extend their shelf life.

Recent insights into Nanoemulsions: Their preparation, properties and applications

The ever-increasing demand for healthy diet by consumers has prompted the research adopting cutting-edge methods that can maintain the quality of fruits and vegetables without the use of preservatives. Emulsion based coating approach has been regarded as a viable way to extend the shelf life of fresh produce. New opportunities are being created in a number of industries, (medicines, cosmetics and food) because of new advancements in the developing field of nanoemulsions. Nanoemulsion based methods are efficient for encapsulating the active ingredients including antioxidants, lipids, vitamins and antimicrobial agents owing to the small droplet size, stability and improved biological activity. This review provides an overview of recent developments in preserving the quality and safety of fresh-cut fruits & vegetables with nanoemulsion as a carrier of functional compounds (antimicrobial agents, antibrowning/antioxidants and texture enhancers). In addition, material and methods used for fabrication of the nanoemulsion is also described in this review. In addition, material and methods used for fabrication, of the nanoemulsion is also present.

Carvacrol-loaded nanoemulsions produced with a natural emulsifier for lettuce sanitization

Carvacrol is an antimicrobial agent that shows potential for eliminating microorganisms in vegetables, increasing food safety. However, intense odor and low water solubility of carvacrol are limiting factors for its application for fresh vegetables sanitization, which can be overcome by nanotechnology. Two different nanoemulsions containing carvacrol (11 mg/mL) were developed by probe sonication: carvacrol-saponin nanoemulsion (CNS) and carvacrol-polysorbate 80 nanoemulsion (CNP). Formulations presented appropriate droplet sizes (from 74.7 nm to 168.2 nm) and high carvacrol encapsulation efficiency (EE) (from 89.5 % to 91.5 %). CNS showed adequate droplet size distribution (PDI < 0.22) and high zeta potential values (around -30 mV) compared to CNP, with saponin chosen for the following experiments. Carvacrol nanoemulsions presented Bacterial Inactivation Concentration (BIC) against the Salmonella cocktail from 5.51 to 0.69 mg/mL and for the E. coli cocktail from 1.84 to 0.69 mg/mL. Among all tested nanoemulsions, CNS1 presented the lowest BIC (0.69 mg/mL) against both bacterial cocktails. Damage to bacterial cells in lettuce treated with nanoemulsion was confirmed by scanning electron microscopy. For lettuce sanitization, CNS1 showed a similar effect to unencapsulated carvacrol, with a high bacterial reduction (>3 log CFU/g) after lettuce immersion for 15 min at 2 × BIC. Using the same immersion time, the CNS1 (2 × BIC) demonstrated equal or better efficacy in reducing both tested bacterial cocktails (>3 log CFU/g) when compared to acetic acid (6.25 mg/mL), citric acid (25 mg/mL), and sodium hypochlorite solution (150 ppm). Lettuce immersed in CNS1 at both concentrations (BIC and 2 × BIC) did not change the color and texture of leaves, while the unencapsulated carvacrol at 2 × BIC darkened them and reduced their firmness. Consequently, carvacrol-saponin nanoemulsion (CNS1) proved to be a potential sanitizer for lettuce.

Enhancing the Stability and Bioaccessibility of Tree Peony Seed Oil Using Layer-by-Layer Self-Assembling Bilayer Emulsions

Tree peony seed oil (TPSO) is an important plant source of n-3 polyunsaturated fatty acid (α-linolenic acid, ALA > 40%) that is receiving increasing attention for its excellent antioxidant and other activities. However, it has poor stability and bioavailability. In this study, a bilayer emulsion of TPSO was successfully prepared using a layer-by-layer self-assembly technique. Among the proteins and polysaccharides examined, whey protein isolate (WPI) and sodium alginate (SA) were found to be the most suitable wall materials. The prepared bilayer emulsion contained 5% TPSO, 0.45% whey protein isolate (WPI) and 0.5% sodium alginate (SA) under selected conditions and its zeta potential, droplet size, and polydispersity index were -31 mV, 1291 nm, and 27%, respectively. The loading capacity and encapsulation efficiency for TPSO were up to 84% and 90.2%, respectively. It was noteworthy that the bilayer emulsion showed significantly enhanced oxidative stability (peroxide value, thiobarbituric acid reactive substances content) compared to the monolayer emulsion, which was accompanied by a more ordered spatial structure caused by the electrostatic interaction of the WPI with the SA. This bilayer emulsion also exhibited markedly improved environmental stability (pH, metal ion), rheological properties, and physical stability during storage. Furthermore, the bilayer emulsion was more easily digested and absorbed, and had higher fatty acid release rate and ALA bioaccessibility than TPSO alone and the physical mixtures. These results suggest that bilayer emulsion containing WPI and SA is an effective TPSO encapsulation system and has significant potential for future functional food development.

Synergistic antibacterial and anti-biofilm mechanisms of ultrasound combined with citral nanoemulsion against Staphylococcus aureus 29213

This study investigated the antibacterial and antibiofilm mechanism of ultrasound (US) combined with citral nanoemulsion (CLNE) against Staphylococcus aureus and mature biofilm. Combined treatments resulted in greater reductions in bacterial numbers compared to ultrasound or CLNE treatments alone. Confocal laser scanning microscopy (CLSM), flow cytometry (FCM), protein nucleic acid leakage, and N-phenyl-l-naphthylamine (NPN) uptake analysis showed that the combined treatment disrupted cell membrane integrity and permeability. Reactive oxygen species (ROS) and malondialdehyde (MDA) assays indicated that US+CLNE exacerbated cellular oxidative stress and membrane lipid peroxidation. Field emission scanning electron microscopy (FESEM) revealed that the synergistic processing of ultrasound and CLNE resulted in cell rupture and collapse. In addition, US+CLNE showed a more pronounced removal effect than both alone in the biofilm on the stainless steel sheet. US+CLNE reduced biomass, the number of viable cells in the biofilm, cell viability and EPS polysaccharide contents. The results of CLSM also showed that US+CLNE disrupted the structure of the biofilm. This research elucidates the synergistic antibacterial and anti-biofilm mechanism of ultrasound combined citral nanoemulsion, which provides a safe and efficient sterilization method for the food industry.

Preparation of Citrus reticulata peel nano-encapsulated essential oil and in vitro assessment of its biological properties

Dental caries is the most common biofilm-dependent oral disease. Streptococcus mutans is among the main microorganisms responsible for the development of dental caries. Nano-suspension of Citrus reticulata (tangerine) peel essential oil in 0.5% (v/v) concentration was prepared and its antibacterial effect on S. mutans in planktonic and biofilm forms as well as its cytotoxic and antioxidant effects were assessed and compared with chlorhexidine (CHX). The minimum inhibitory concentration (MIC) of free essential oil, nano-encapsulated essential oil, and CHX was 5.6% (v/v), 0.0005% (v/v), and 0.0002% (w/v), respectively. The percentage of biofilm inhibition by the free essential oil, nano-encapsulated essential oil, and CHX at half-MIC was 67.3%, 24%, and 90.6%, respectively. The nano-encapsulated essential oil had no cytotoxicity and showed significant antioxidant effects in different concentrations. Nano-encapsulation of tangerine peel essential oil significantly enhanced its biological activities in much lower concentrations than the free essential oil (11,000 times diluted). It also showed lower cytotoxicity and higher antibiofilm effects in sub-MICs compared with CHX, indicating the optimal potential of tangerine nano-encapsulated essential oil for incorporation in the composition of organic antibacterial and antioxidant mouth rinses.

Comparison of antibacterial and antioxidant potentials of pure and nanoemulsified Nepeta pogonosperma essential oil

The current study aimed to investigate the antiradical and antibacterial potential of pure and its nanoemulsified (NNE) Nepeta pogonosperma essential oil (PNE). Antimicrobial activity of the essential oil against two Gram-positive (E. faecalis and B. cereus) and two Gram-negative (M. catarrhalis and K. pneumonia) food-related pathogens during 60-day storage was investigated based on disc diffusion, minimum inhibition concentration (MIC), and minimum bactericidal concentration (MBC). The chemical compounds of Nepeta essential oil were estimated by GC/MS. The physical properties of the nanoemulsion including polydispersity index (PDI), mean particle diameter, and viscosity were also determined. 4aα,7α,7aβ-Nepetalactone (46.31%), 1,8-cineole (23.13%), and (Z)-α-bisabolene (4.01%) were the main compounds of this essential oil. The Nepeta nanoemulsion had a mean droplet diameter of 254.07 nm, PDI of 0.281, and viscosity of 0.887 cP. NNE had stability for up to 60 days. The PNE showed a higher IC50 value than NNE (p < .05). During storage, the antiradical performance of both PNE and NNE was decreased (p < .05). However, emulsification was successful to control this decreasing trend. E. faecalis was the most susceptible bacteria to PNE and NNE, while the lowest inhibition zone was obtained for K. pneumoniae. At the first time, the antibacterial effect of PNE was more than NNE. However, over time nanoemulsion became more successful in maintaining its antibacterial effect. Overall, the incorporation of Nepeta pogonosperma essential oil into a nanoemulsion system can be a promising system to maintain the bioactivity of the essential oil for a longer time.

Nanoemulsion-based approach to preserve muscle food: A review with current knowledge

Muscle foods are regarded as nutritionally dense foods while they are prone to spoilage by action of microorganism and oxidation. Recently, the consumer's preference is mostly toward minimally processed foods as well as preserved with natural preservatives. However, natural extract directly to the food matrix has several drawbacks. Hence development and applications of nanoemulsion has gained importance for the preservation of muscle foods to meet consumer requirements with enhanced food safety. Nanoemulsion utilizes natural extracts at much lower concentration with higher preservative abilities over original components. Nanoemulsions offer protection to the active component from degradation and ensure longer bioavailability. Novel techniques used for formulation of nanoemulsion provide stability to the emulsion with desirable qualities to improve their impacts. The application of nanoemulsion is known to enhance the preservative action of nanoemulsions by improving the microbial safety and oxidative stability in nanoform. This review provides recent updates on different methods used for formulation of nanoemulsions from different sources. Besides, successful application of nanoemulsion derived using natural agents for muscle food preservation and shelf life extension are reviewed. Thus, the application of nanoemulsion to extend shelf life and maintain quality is suggested for muscle foods.

Application of essential oils as natural biopesticides; recent advances

There is an urgent need for the development of sustainable and eco-friendly pesticide formulations since common synthetic pesticides result in many adverse effects on human health and the environment. Essential oils (EOs) are a mixture of volatile oils produced as a secondary metabolite in medicinal plants, and show activities against pests, insects, and pathogenic fungi. Their chemical composition is affected by several factors such as plant species or cultivar, geographical origin, environmental conditions, agricultural practices, and extraction method. The growing number of studies related to the herbicidal, insecticidal, acaricidal, nematicidal, and antimicrobial effects of EOs demonstrate their effectiveness and suitability as sustainable and environment-friendly biopesticides. EOs can biodegrade into nontoxic compounds; at the same time, their harmful and detrimental effects on non-target organisms are low. However, few biopesticide formulations based on EOs have been turned into commercial practice upto day. Several challenges including the reduced stability and efficiency of EOs under environmental conditions need to be addressed before EOs are widely applied as commercial biopesticides. This work is an overview of the current research on the application of EOs as biopesticides. Findings of recent studies focusing on the challenges related to the use of EOs as biopesticides are also discussed.

Minimally processed fruits as vehicles for foodborne pathogens

The consumption of minimally processed fruit (MPF) has increased over the last decade due to a novel trend in the food market along with the raising consumers demand for fresh, organic, convenient foods and the search for healthier lifestyles. Although represented by one of the most expanded sectors in recent years, the microbiological safety of MPF and its role as an emergent foodborne vehicle has caused great concern to the food industry and public health authorities. Such food products may expose consumers to a risk of foodborne infection as they are not subjected to prior microbial lethal methods to ensure the removal or destruction of pathogens before consumption. A considerable number of foodborne disease cases linked to MPF have been reported and pathogenic strains of Salmonella enterica, Escherichia coli, Listeria monocytogenes, as well as Norovirus accounted for the majority of cases. Microbial spoilage is also an issue of concern as it may result in huge economic losses among the various stakeholders involved in the manufacturing and commercialization of MPF. Contamination can take place at any step of production/manufacturing and identifying the nature and sources of microbial growth in the farm-to-fork chain is crucial to ensure appropriate handling practices for producers, retailers, and consumers. This review aims to summarize information about the microbiological hazards associated with the consumption of MPF and also highlight the importance of establishing effective control measures and developing coordinated strategies in order to enhance their safety.

Essential oils and their active components applied as: free, encapsulated and in hurdle technology to fight microbial contaminations. A review

Microbial contaminations are responsible for many chronic, healthcare, persistent microbial infections and illnesses in the food sector, therefore their control is an important public health challenge. Over the past few years, essential oils (EOs) have emerged as interesting alternatives to synthetic antimicrobials as they are biodegradable, extracted from natural sources and potent antimicrobials. Through their multiple mechanisms of actions and target sites, no microbial resistance has been developed against them till present. Although extensive documentation has been reported on the antimicrobial activity of EOs, comparisons between the use of whole EOs or their active components alone for an antimicrobial treatment are less abundant. It is also essential to have a good knowledge about EOs to be used as alternatives to the conventional antimicrobial products such as chemical disinfectants. Moreover, it is important to focus not only on planktonic vegetative microorganisms, but to study also the effect on more resistant forms like spores and biofilms. The present article reviews the current knowledge on the mechanisms of antimicrobial activities of EOs and their active components on microorganisms in different forms. Additionally, in this review, the ultimate advantages of encapsulating EOs or combining them with other hurdles for enhanced antimicrobial treatments are discussed.

Antioxidative, anticancer, and antibacterial activities of a nanogel containing Mentha spicata L. essential oil and electrospun nanofibers of polycaprolactone-hydroxypropyl methylcellulose

BACKGROUND

As the largest organ, the skin has been frequently affected by trauma, chemical materials, toxins, bacterial pathogens, and free radicals. Recently, many attempts have been made to develop natural nanogels that, besides hydrating the skin, could also be used as antioxidant or antibacterial agents.

METHODS

In this study, the chemical composition of the Mentha spicata essential oil was first investigated using GC-MS analysis. Its nanoemulsion-based nanogel was then investigated; successful loading of the essential oil in the nanogel was confirmed using FTIR analysis. Besides, nanogel's antioxidative, anticancer, and antibacterial activities were investigated.

RESULTS

Carvone (37.1%), limonene (28.5%), borneol (3.9%), β-pinene (3.3%), and pulegone (3.3%) were identified as five major compounds in the essential oil. By adding carboxymethylcellulose (3.5% w/v) to the optimal nanoemulsion containing the essential oil (droplet size of 196 ± 8 nm), it was gelified. The viscosity was fully fitted with a common non-Newtonian viscosity regression, the Carreau-Yasuda model. The antioxidant effect of the nanogel was significantly more potent than the essential oil (P < 0.001) at all examined concentrations (62.5-1000 µg/mL). Furthermore, the potency of the nanogel with an IC50 value of 55.0 µg/mL was substantially more (P < 0.001) than the essential oil (997.4 µg/mL). Also, the growth of Staphylococcus aureus and Escherichia coli after treatment with 1000 µg/mL nanogel was about 50% decreased compared to the control group. Besides, the prepared electrospun polycaprolactone-hydroxypropyl methylcellulose nanofibers mat with no cytotoxic, antioxidant, or antibacterial effects was proposed as lesion dressing after treatment with the nanogel. High potency, natural ingredients, and straightforward preparation are advantages of the prepared nanogel. Therefore, it could be considered for further consideration in vivo studies.

Growth Inhibition of Listeria monocytogenes in Fresh White Cheese by Mustard Oil Microemulsion

ABSTRACT

Although essential oils exhibit antimicrobial properties, their application is limited, owing to their strong volatility and poor water solubility. Emulsification is a valid strategy for improving chemical stability. In this study, we prepared a mustard oil (MO) emulsion with egg yolk lecithin and evaluated its antimicrobial activity against Listeria monocytogenes in vitro and in cheese curd. The particle size of the MO emulsion was approximately 0.19 μm and remained stable for 30 days of storage. The MO emulsion showed strong antimicrobial activity against L. monocytogenes in vitro. Moreover, 40 ppm of MO was sufficient to inhibit the growth of L. monocytogenes in culture, and the addition of 160 ppm of MO decreased the population of L. monocytogenes. When 50 ppm of emulsified MO was added to milk during cheese curd production and it was stored at 10°C for 10 days, the growth of L. monocytogenes was suppressed. When the cheese curd with MO emulsion was stored at 4°C, the bacterial count was significantly decreased (P < 0.05), and no bacterial growth was observed after 14 days of storage. Furthermore, the sensory characteristics of cheese curd with the MO emulsion were acceptable. These results indicate MO emulsions may be useful in controlling the growth of L. monocytogenes in fresh cheese.

HIGHLIGHTS

Promising advances in nanobiotic-based formulations for drug specific targeting against multidrug-resistant microbes and biofilm-associated infections

Antimicrobial agents and alternative strategies to combat bacterial infections have become urgent due to the rapid development of multidrug-resistant bacteria caused by the misuse and overuse of antibiotics, as well as the ineffectiveness of antibiotics against difficult-to-treat infectious diseases. Nanobiotics is one of the strategies being explored to counter the increase in antibiotic-resistant bacteria. Nanobiotics are antibiotic molecules encapsulated in nanoparticles or artificially engineered pure antibiotics that are ≤ 100 nm in size in at least one dimension. Formulation scientists recognize nanobiotic delivery systems as an effective strategy to overcome the limitations associated with conventional antibiotic therapy. This review highlights the general mechanisms by which nanobiotics can be used to target resistant microbes and biofilm-associated infections. We focus on the design elements, properties, characterization, and toxicity assessment of organic nanoparticles, inorganic nanoparticle and molecularly imprinted polymer-based nano-formulations that can be designed to improve the efficacy of nanobiotic formulation.

Nanoemulsion and Encapsulation Strategy of Hydrophobic Oregano Essential Oil Increased Human Prostate Cancer Cell Death via Apoptosis by Attenuating Lipid Metabolism

Origanum vulgare essential oil (EO) is traditionally well-known for its aromatic properties and biomedical applications, including anticancer. This was the first report where oregano essential oil-based nano emulsion (OENE) was synthesized for studying its effects on prostate cancer cell lines (PC3). At first, we have synthesized OENE and characterized using various spectroscopic analyses. The toxicity and inhibitory concentration (IC50) of OENE toward prostate cancer by MTT analysis were performed. The lipid biogenesis mediated, molecular target pathway analyses were performed using fluorescence cellular staining techniques, real-time RT-PCR, or western blotting analysis. OENE showed IC50 at 13.82 µg/mL and significantly induced distinct morphological changes, including cell shrinkage, cell density, and cell shape reduction. In addition, OENE could also significantly decreased lipid droplet accumulation which was confirmed by studying mRNA transcripts of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) (0.31-fold), fatty acid synthase (FASN) (0.18-fold), and sterol regulatory element-binding protein (SREPB1) (0.11-fold), respectively. Furthermore, there is a significant upregulation BAX (BCL2 associated X) and caspase 3 expressions. Nevertheless, OENE decreased the transcript level of BCL2 (B-cell lymphoma 2), thus resulting in apoptosis. Overall, our present work demonstrated that OENE could be a therapeutic target for the treatment of prostate cancer and warrants in vivo studies.

High Hydrostatic Pressure-Based Combination Strategies for Microbial Inactivation of Food Products: The Cases of Emerging Combination Patterns

The high demand for fresh-like characteristics of vegetables and fruits (V&F) boosts the industrial implementation of high hydrostatic pressure (HHP), due to its capability to simultaneously maintain original organoleptic characteristics and to achieve preservative effect of the food. However, there remains great challenges for assuring complete microbial inactivation only relying on individual HHP treatments, including pressure-resistant strains and regrowth of injured microbes during the storage process. Traditional HHP-assisted thermal processing may compromise the nutrition and functionalities due to accelerated chemical kinetics under high pressure conditions. This work summarizes the recent advances in HHP-based combination strategies for microbial safety, as exemplified by several emerging non-thermally combined patterns with high inactivation efficiencies. Considerations and requirements about future process design and development of HHP-based combination technologies are also given.