Octenylsuccinated alginate as a delivery agent for encapsulation of bergamot essential oil: Preparation, functional properties and release behavior

This study evaluate the effect of succinylation of sodium alginate (ALG) by octenyl succinic anhydride (OSA) and its effect on the bergamot essential oil (BEO)-loaded ALG beads. The physico-chemical, antioxidant, antibacterial, and in vitro release properties of BEO-loaded ALG beads were assessed. The presence of BEO in alginate beads was assessd using Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) experiments. The higher amount of BEO in modified alginate beads at higher degree of substitution (DS) has been confirmed. Accordingly, it was discovered that the DS has notable effects on encapsulation efficiency (EE), loading capacity (LC) of beads, so that the values of EE and LC were about 31-75 % and 19-45 %, respectively, when the DS value of ALG was 0.00-0.022. Besides, BEO-loaded beads prepared using high DS, exhibited higher total phenolic compound (TPC = 21.101 mg garlic acid/g brad), good antioxidant activity (DPPH radical scavenging activity ≈ 69 %) and antibacterial properties (against E. coli and S. aureus). In vitro release analysis showed the initial fast release followed by a slow-release. OSA modification slowed down the release rate of bergamot essential oil from alginate beads. Also, the release of BEO from the beads followed Fickian diffusion.

Assessment of chitosan coating enriched with Citrus limon essential oil on the quality characteristics and shelf life of beef meat during cold storage

The present work aimed to assess the effects of chitosan coating comprising Citrus limon essential oil (CLEO) as an antimicrobial and antioxidant on the quality and the shelf-life of beef meat during storage in cold temperatures. The microbial, chemical, and sensory characteristics of beef meat were repeatedly evaluated. The outcomes showed that CLEO had a substantial preservative effect on refrigerated beef meat by reducing total volatile basic nitrogen compounds (TVB-N), inhibiting the replication of microorganisms (p < 0.05), and decreasing oxidation (p < 0.05) during storage. The incorporation of CLEO into chitosan coating significantly reduced (p < 0.05), TBARS, especially for the Nano-CS- ClEO 2 % and 4 % groups, with values at the end of storage of approximately 0.68 and 1.01 mg MDA/kg respectively. Moreover, the meat treatments with essential oils led to lower carbonyl content production in compared to other groups that treated without essential oils. Coated beef meat had the highest inhibitory effects against microbial growth. The counts of Enterobacteriaceae, lactic acid bacteria (LAB), psychrophilic, and mesophilic bacteria were significantly lower (p < 0.05) in the Nano-CS- ClEO 2 % (1.1, 4.2, 6.2, and 6.32 Log CFU/g, respectively) at day 16. The sensory evaluation indicated that this coating with chitosan nanoemulsions in combination with ClEOs could significantly preserve sensory characteristics of beef meat during storage. Moreover, concerning sensory features, the control samples gained the maximum score. Additionally, the group that contains chitosan in combination with 4 % ClEO nanoliposomes had the highest inhibition of microbial growth, reduced sensory changes, and extending the shelf life of beef meat (p < 0.05). In conclusion, nanoemulsions containing Citrus limon essential oil had a significant preservation effect on beef meat during refrigerated storage by preventing the microorganism's proliferation and decreasing the oxidation of fat and protein (p < 0.05). Therefore, they are suggested to extend the durability of fresh meat products during refrigerated storage.

Genetic diversity, essential oil's chemical constituents of aromatic plant Mesosphaerum suaveolens (L.) Kuntze Syn. Hyptis suaveolens (L.) Poit. and its uses in crop protection: a review

This review provides evidence on the genetic diversity, chemical constituents, and ecotoxicology of Mesosphaerum suaveolens ' essential oil. It emphasizes the agricultural benefits such as crop protection effectiveness of the plant and highlights the existing knowledge gaps and research perspectives to promote its utilization in agriculture. A systematic and extensive review of the literature was done and all pertinent full-text articles and abstracts were analyzed and incorporated into the review. Mesosphaerum suaveolens is used traditionally in pharmacology to treat several diseases such as malaria, constipation, stomach problems, and renal inflammation. It also treats cramps, digestive infections, headaches, and skin infections. To date, very few studies have been conducted worldwide about its genetic diversity. These studies highlighted three morphological variants, the blue-flowering, the white-flowering, and the light-purple flowering M. suaveolens. Its wide biological actions may be attributed to the numerous groups of chemical constituents in its essential oil including monoterpenes, sesquiterpenes, and diterpenes. Biological studies highlighted evidence of M. suaveolens being used as an antifungal, bactericidal, antimicrobial, insecticidal, and repellent plant. The essential oil extracted from M. suaveolens showed significant potential for the control of agricultural pests such as Sitiophilus zeamais, Helicoverpa armigera and Helminthosporium oryzae. M. suaveolens is commonly used worldwide as a pesticidal plant in healthcare, agriculture, and food preservation. However, there is a lack of studies concerning the toxicity and effectiveness of isolated potent phytotoxic substances, the efficacy screening in the field, the genetic diversity, the essential oil yield, and productivity. Consequently, further studies are required to fill the knowledge gaps.

Metal-organic frameworks-based moisture responsive essential oil hydrogel beads for fresh-cut pineapple preservation

The preservation of fresh-cut fruits and vegetables has attracted attention to the shelf-life reduction caused by high humidity. Herein, alginate/copper ions cross-linking, in-situ growth and self-assembly techniques of metal-organic frameworks (MOFs) were utilized to prepare a moisture responsive hydrogel bead (HKUST-1@ALG). As the multistage porous structure formation, tea tree essential oil (TTO) load capacity in hydrogel bead (TTO-HKUST-1@ALG) was increased from 6.1% to 21.6%. TTO-HKUST-1@ALG had excellent moisture response performance, and the release rates of TTO increased from 33.89% to 70.98% with moisture increasing from 45% to 95%. Besides, TTO-HKUST-1@ALG exhibited excellent antimicrobial, antioxidant capacity, and biocompatibility. During storage, TTO-HKUST-1@ALG effectively improved the cell membrane integrity by maintaining the balance of reactive oxygen species metabolism. The degradation of cell wall structure and tissue softening were delayed by inhibiting the cell wall-degrading enzymes activity. Briefly, TTO-HKUST-1@ALG improved the storage quality and extended shelf-life of fresh-cut pineapple, which was a promising preservative.

Influence of the Extraction Method on the Biological Potential of Solidago virgaurea L. Essential Oil and Hydrolates

Solidago virgaurea L., or European goldenrod, has a long tradition in folk medicine due to the wide range of its biological activity. This paper aimed to investigate the antimicrobial and antioxidative potential of S. virgaurea essential oil and hydrolates obtained by traditional and novel extraction techniques. For that purpose, hydrodistillation, microwave-assisted hydrodistillation and solvent-free extraction were performed. Analysis of the composition of essential oils indicated the presence of 59 different compounds with cyclocolorenone, germacrene D and spathulenol being the dominant in all essential oil samples. Antimicrobial activity was detected in all the analyzed samples, with higher effect on Gram-positive microorganisms compared to Gram-negative. Regarding the type of performed extraction process, the introduction of microwaves induced higher antimicrobial and antioxidative potential in both essential oils and hydrolates. Hydrolates obtained in microwave-assisted processes had pronounced antioxidative activity, which creates a good basis for further investigation of this side product's potential use in the food, cosmetic and pharmaceutical industries.

Enhancing bioactivity of Callistemon citrinus (Curtis) essential oil through novel nanoemulsion formulation

The main focus of this study was to create a stable and efficient nanoemulsion (NE) using Callistemon citrinus essential oil (EO). Various factors affecting the NE's stability were optimized including oil %, Tween 80%, time of sonication, and its accelerated stability was examined. The research also considered the antibacterial, antifungal, and larvicidal effects of the optimized NE (B10). The optimum NE stood out for its stability, featuring a particle size of 33.15 ± 0.32 nm. Analysis via IR spectroscopy confirmed successful EO encapsulation in B10. The formulation remained stable for six months, with B10 showing significantly higher antibacterial and antifungal potency compared to the pure oil. When samples were subjected to tests against Fusarium oxysporum, B10 exhibited a MIC value of 62.5 mg/mL, whereas the pure oil showed a MIC value of 250 mg/mL. This indicates that the B10 formulation was 50 times more effective than the EO. In terms of antibacterial activity against Escherichia coli, the MIC value was 0.256 mg/mL for B10 and 4 mg/mL for the EO. Also, pure oil and B10 displayed larvicidal effects against Chilo suppressalis (Walker) larvae, with B10 eliminating 95.2% of larvae in 48 h. Overall, stable and optimum C. citrinus NE with its strong antimicrobial qualities, shows promise as an effective fungicide and insecticide.

Synergistic antifungal mechanism of cinnamaldehyde and nonanal against Aspergillus flavus and its application in food preservation

Aspergillus flavus colonization on agricultural products during preharvest and postharvest results in tremendous economic losses. Inspired by the synergistic antifungal effects of essential oils, the aims of this study were to explore the mechanism of combined cinnamaldehyde and nonanal (SCAN) against A. flavus and to evaluate the antifungal activity of SCAN loading into diatomite (DM). Shriveled mycelia were observed by scanning electron microscopy, especially in the SCAN treatment group. Calcofluor white staining, transmission electron microscopy, dichloro-dihydro-fluorescein diacetate staining and the inhibition of key enzymes in tricarboxylic acid cycle indicated that the antifungal mechanism of SCAN against A. flavus was related to the cell wall damage, reactive oxygen species accumulation and energy metabolism interruption. RNA sequencing revealed that some genes involved in antioxidation were upregulated, whereas genes responsible for cell wall biosynthesis, oxidative stress, cell cycle and spore development were significantly downregulated, supporting the occurrence of cellular apoptosis. In addition, compared with the control group, conidia production in 1.5 mg/mL DM/cinnamaldehyde, DM/nonanal and DM/SCAN groups were decreased by 27.16%, 48.22% and 76.66%, respectively, and the aflatoxin B1 (AFB1) contents decreased by 2.00%, 73.02% and 84.15%, respectively. These finding suggest that DM/SCAN complex has potential uses in food preservation.

Microencapsulation to Harness the Antimicrobial Potential of Essential Oils and Their Applicability in Dairy Products: A Comprehensive Review of the Literature

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

Coatings Based on Essential Oils for Combating Antibiotic Resistance

In the current era of widespread antimicrobial resistance, the utilization of essential oils (EOs) derived from plants has emerged as a promising alternative in combating pathogens that have developed resistance to antibiotics. This review explores the therapeutic potential of essential oils as valuable tools in restoring the efficacy of antibiotics, highlighting their unique ability to affect bacteria in multiple ways and target various cellular systems. Despite the challenge of elucidating their precise mode of action, EOs have shown remarkable results in rigorous testing against a diverse range of bacteria. This review explores the multifaceted role of EOs in combating bacterial microorganisms, emphasizing their extraction methods, mechanisms of action, and comparative efficacy against synthetic antibiotics. Key findings underscore the unique strategies EOs deploy to counter bacteria, highlighting significant differences from conventional antibiotics. The review extends to advanced coating solutions for medical devices, exploring the integration of EO formulations into these coatings. Challenges in developing effective EO coatings are addressed, along with various innovative approaches for their implementation. An evaluation of these EO coatings reveals their potential as formidable alternatives to traditional antibacterial agents in medical device applications. This renaissance in exploring natural remedies emphasizes the need to combine traditional wisdom with modern scientific advancements to address the urgent need for effective antimicrobial solutions in the post-antibiotic era.

Recent advances in spoilage mechanisms and preservation technologies in beef quality: A review

Beef is a popular meat product that can spoil and lose quality during postharvest handling and storage. This review examines different preservation methods for beef, from conventional techniques like low-temperature preservation, irradiation, vacuum packing, and chemical preservatives, to novel approaches like bacteriocin, essential oil, and non-thermal technologies. It also discusses how these methods work and affect beef quality. The review shows that beef spoilage is mainly due to enzymatic and microbial activities that impact beef freshness, texture, and quality. Although traditional preservation methods can extend beef shelf life, they have some drawbacks and limitations. Therefore, innovative preservation methods have been created and tested to improve beef quality and safety. These methods have promising results and potential applications in the beef industry. However, more research is needed to overcome the challenges and barriers for their commercialization. This review gives a comprehensive and critical overview of the current and emerging preservation methods for beef and their implications for the beef supply chain.

Bioactivities of Jojoba Oil Beyond Skincare

Jojoba oil, which is extracted from jojoba plant seeds that are native to North America, possesses a unique molecular structure and is distinct from other oils. Unlike typical oils, which mostly contain triglycerides, jojoba oil is composed of long monounsaturated esters, affording it exceptional properties and is valuable across cosmetics, chemicals, and pharmaceuticals. While jojoba oil is prevalent in beauty and skincare today, its seeds and oil have ancient roots in folk medicine, used for treating skin and scalp issues, wounds, sore throats, obesity, and even cancer, while enhancing immunity and fostering hair growth. Modern research underscores jojoba oil's pharmacological versatility, demonstrating antioxidant, antidiabetic, anti-acne, anti-inflammatory, antipyretic, and antibacterial properties. Notably, there has been a surge in its utilization in pharmaceuticals, particularly in topical, transdermal, and parenteral formulations. This review provides a comprehensive overview of jojoba oil, encompassing its chemical composition, extraction techniques, health advantages, and pharmaceutical application developments.

Spontaneous nanoemulsification of cinnamon essential oil: Formulation, characterization, and antibacterial and antibiofilm activity against fish spoilage caused by Serratia rubidaea BFMO8

The contemporary food industry's uses of nanoemulsions (NEs) include food processing, effective nutraceutical delivery, the development of functional chemicals, and the synthesis of natural preservatives, such as phytocompounds. Although cinnamon essential oil (CEO) is widely used in the cosmetic, pharmaceutical, and food industries, it is difficult to add to aqueous-based food formulations due to its weak stability and poor water solubility. This study describes the formulation of a CEO nanoemulsion (CEONE) by spontaneous emulsification and evaluates its antibacterial and antibiofilm properties against biofilm-forming Serratia rubidaea BFMO8 isolated from spoiled emperor fish (Lethrinus miniatus). Bacteria causing spoilage in emperor fish were isolated and identified as S. rubidaea using common morphological, cultural, and 16S RNA sequencing methods, and their ability to form biofilms and their susceptibility to CEONE were assessed using biofilm-specific methods. The spontaneous emulsification formulation of CEONE was accomplished using water and Tween 20 surfactant by manipulating organic and aqueous phase interface properties and controlling particle growth by capping surfactant increases. The best emulsification, with highly stable nano-size droplets, was accomplished at 750 rpm and a 1:3 ratio concentration. The stable CEONE droplet size, polydispersity index, and zeta potential values were 204.8 nm, 0.115, and -6.05 mV, respectively. FTIR and high-resolution liquid chromatography-mass spectrometry (HR-LCMS) analyses have revealed carboxyl, carbonyl, and phenol-like primary phytochemical functional groups in CEO and CEONE, which contribute to their antibacterial and antibiofilm properties.

Assessing the virucidal activity of essential oils against feline calicivirus, a non-enveloped virus used as surrogate of norovirus

Norovirus (NoV) causes serious gastrointestinal disease worldwide and is regarded as an important foodborne pathogen. Due the difficulties of in vitro cultivation for human NoV, alternative caliciviruses (i.e., feline calicivirus, FCV, or murine NoV) have long been used as surrogates for in vitro assessment of the efficacy of antivirals. Essential oils (EOs) are natural compounds that have displayed antimicrobial and antioxidant properties. We report in vitro the virucidal efficacy of four EOs, Melissa officinalis L. EO (MEO), Thymus vulgaris L. EO (TEO), Rosmarinus officinalis L. EO (REO), and Salvia officinalis L. EO (SEO) against FCV at different time contacts (10, 30 min, 1, 4 and 8 h). At the maximum non-cytotoxic concentration and at 10- and 100- fold concentrations over the cytotoxic threshold, the EOs did not decrease significantly FCV viral titers. However, MEO at 12,302.70 μg/mL exhibited a significant efficacy decreasing the viral titer by 0.75 log10 Tissue Culture Infectious Dose (TCID50)/50 μl after 10 min as compared to virus control. In this study, virucidal activity of four EOs against FCV, was investigated. A lack of virucidal efficacy of TEO, REO and SEO at different compound concentrations and time contacts against FCV was observed whilst MEO was able to significantly decrease FCV titer.

Efficacy of Essential Oil Vapours in Reducing Postharvest Rots and Effect on the Fruit Mycobiome of Nectarines

Nectarines can be affected by many diseases, resulting in significant production losses. Natural products, such as essential oils (EOs), are promising alternatives to pesticides to control storage rots. This work aimed to test the efficacy of biofumigation with EOs in the control of nectarine postharvest diseases while also evaluating the effect on the quality parameters (firmness, total soluble solids, and titratable acidity) and on the fruit fungal microbiome. Basil, fennel, lemon, oregano, and thyme EOs were first tested in vitro at 0.1, 0.5, and 1.0% concentrations to evaluate their inhibition activity against Monilinia fructicola. Subsequently, an in vivo screening trial was performed by treating nectarines inoculated with M. fructicola, with the five EOs at 2.0% concentration by biofumigation, performed using slow-release diffusers placed inside the storage cabinets. Fennel, lemon, and basil EOs were the most effective after storage and were selected to be tested in efficacy trials using naturally infected nectarines. After 28 days of storage, all treatments showed a significant rot reduction compared to the untreated control. Additionally, no evident phytotoxic effects were observed on the treated fruits. EO vapors did not affect the overall quality of the fruits but showed a positive effect in reducing firmness loss. Metabarcoding analysis showed a significant impact of tissue, treatment, and sampling time on the fruit microbiome composition. Treatments were able to reduce the abundance of Monilinia spp., but basil EO favored a significant increase in Penicillium spp. Moreover, the abundance of other fungal genera was found to be modified.

Characterization and investigation of cytotoxicity and antimicrobial properties of coencapsulated limonene and thymol into the Ferula assafoetida gum microparticles

Thymol (Th) and d-limonene (L) exhibit low stability and are prone to oxidation when exposed to air, light, humidity, and high temperatures. This study examined the coencapsulation of Th and L into Ferula assafoetida gum (AFG) microparticles. Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analyzer (TGA) were done to characterize the obtained complexes. Furthermore, the encapsulation efficiency, antibacterial properties, cytotoxicity, and anticancer properties of both the free and encapsulated forms of L and Th were measured. For all samples, by increasing the percentage of bioactive compound (L, Th, and L-Th) from 2.5 to 5 % w/w, the EE was increased. FTIR and XRD analysis results demonstrated that Th and L were successfully incorporated into the AFG. Additionally, thermogravimetric analysis showed that in the thermal graphs of all samples, the first weight loss occurred between 30 °C and 160 °C, which was due to the evaporation of water. In the free L and Th graph, a sharp reduction peak was observed in which 80 % of compounds were lost. These reduction peaks disappeared in the thermal graphs of L: AFG and Th: AFG revealing that the thermal stability of Th and L was significantly increased upon their incorporation into the AFG. The inclusion of Th into the AFG also led to an increase in its antibacterial activity, while L exhibited acceptable antibacterial activity, albeit not as high as Th. Additionally, according to the MIC results, Th: AFG had the best antibacterial activity among all compounds, especially on gram-positive bacteria. According to the result of the MTT assay, there was a significant difference between the IC50 of free Th (123.4 μg/ml) and Th: AFG (2312 μg/ml), and free L (1762 μg/ml) and L: AFG (2480 μg/ml) showing that encapsulated Th and L into the AFG has decreased the cytotoxicity of free compounds against L929 cell line. Also, Th: AFG had the best anticancer activity against Hella and CT26 cell lines among all compounds. Finally, the flow cytometry analysis demonstrated that the encapsulated particles effectively eliminated cancer cells. The outcomes imply that AFG can be employed as a suitable delivery system to enhance the use of Th and L into the food and pharmaceutical industries.

Effect of pimenta essential oil against Salmonella Agona and Salmonella Saintpaul in ground turkey meat and nonprocessed turkey breast meat

Salmonella enterica Agona (S. Agona) and Salmonella enterica Saintpaul (S. Saintpaul) are among the emerging drug-resistant Salmonella in turkey production and processing. Rapid solutions to control emerging and uncommon serotypes such as S. Agona and S. Saintpaul are needed. This study tested pimenta essential oil (PEO) as a processing antibacterial against S. Agona and S. Saintpaul in experiments representative of different stages of turkey processing. The compound effectively reduced S. Agona and S. Saintpaul in nutrient broth studies and with mature biofilm assays. PEO was tested against a combination of S. Agona and S. Saintpaul in ground turkey meat and nonprocessed breast meat. In the first experiment with ground turkey, samples were inoculated with a mixture of S. Agona and S. Saintpaul (∼3 log10 CFU/g) and treated with PEO at different concentrations (0% PEO, 0.25% PEO, 0.5% PEO, 1% PEO, 2% PEO, and 2.5% PEO). In the second experiment with turkey breast, samples inoculated with ∼3 log10 CFU/g (SA+SP) were dipped in different concentrations of PEO with chitosan (CN) for 2 min. In both these experiments, samples were stored at 4°C, and Salmonella recovery was carried out at 0, 1, 3, 5, and 7 d. All experiments followed a completely randomized design and were repeated 6 times (n = 6). Statistical analysis was done using the PROC-ANOVA procedure of SAS. In the ground turkey meat, PEO at or above 2% reduced 2 log10 CFU/g of Salmonella by day 1. PEO at 2.5% in ground turkey meat resulted in enrichment-negative samples by 1 min, indicative of the rapid killing effect of the compound at a high concentration of PEO (P ≤ 0.05). A maximum reduction of 1.7 log10 CFU Salmonella/g of turkey breast meat was obtained after 2 min of dip treatment containing CN and 2.5% PEO. Results indicate that PEO could be used as a plant-based processing antibacterial against S. Agona and S. Saintpaul in turkey processing. Upscaling to plant-level studies is necessary before recommending its usage.

Deep eutectic solvents based in situ isolation technique for extractive deterpenation of essential oils

Essential oils, intricate blends of volatile compounds obtained from a variety of sources, play a crucial role in numerous industries. To elevate product quality, deterpenation becomes an indispensable step. This study proposes an in situ isolation technique based on deep eutectic solvents (DESs) for the deterpenation of essential oil. Salient features of relevant compounds were obtained using conductor-like screening model for real solvents (COSMO-RS) and density functional theory (DFT) methods to predict deterpenation performance. Tetrabutylammonium chloride (TBAC) was chosen based on the results of theoretical analysis and experiment to extract hydroxy-terpenoids. COSMO-RS was employed to evaluate the extraction performance at different molar ratios, and then combined with experimental analysis to determine the optimal conditions. The σ-profiles of organic solvents and their interactions with terpene revealed n-hexane to be the best solvent for purifying DES. TBAC and terpenoids were obtained through the re-extraction procedure, with a recovery of 81.8-84.4%.

Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections

Salmonella is a major foodborne pathogen and a leading cause of gastroenteritis in humans and animals. Salmonella is highly pathogenic and encompasses more than 2600 characterized serovars. The transmission of Salmonella to humans occurs through the farm-to-fork continuum and is commonly linked to the consumption of animal-derived food products. Among these sources, poultry and poultry products are primary contributors, followed by beef, pork, fish, and non-animal-derived food such as fruits and vegetables. While antibiotics constitute the primary treatment for salmonellosis, the emergence of antibiotic resistance and the rise of multidrug-resistant (MDR) Salmonella strains have highlighted the urgency of developing antibiotic alternatives. Effective infection management necessitates a comprehensive understanding of the pathogen's epidemiology and transmission dynamics. Therefore, this comprehensive review focuses on the epidemiology, sources of infection, risk factors, transmission dynamics, and the host range of Salmonella serotypes. This review also investigates the disease characteristics observed in both humans and animals, antibiotic resistance, pathogenesis, and potential strategies for treatment and control of salmonellosis, emphasizing the most recent antibiotic-alternative approaches for infection control.

The efficient activity of plant essential oils for inhibiting Botrytis cinerea and Penicillium expansum: Mechanistic insights into antifungal activity

Botrytis cinerea and Penicillium expansum produce deterioration in fruit quality, causing losses to the food industry. Thus, plant essential oils (EOs) have been proposed as a sustainable alternative for minimizing the application of synthetic fungicides due to their broad-spectrum antifungal properties. This study investigated the efficacy of five EOs in suppressing the growth of B. cinerea and P. expansum and their potential antifungal mechanisms. EOs of Mentha × piperita L., Origanum vulgare L., Thymus vulgaris L., Eucalyptus globules Labill., and Lavandula angustifolia Mill., were screened for both fungi. The results showed that the EO of T. vulgaris and O. vulgare were the most efficient in inhibiting the growth of B. cinerea and P. expansum. The concentration increase of all EO tested increased fungi growth inhibition. Exposure of fungi to EOs of T. vulgaris and O. vulgare increased the pH and the release of constituents absorbing 260 nm and soluble proteins, reflecting membrane permeability alterations. Fluorescence microscopic examination revealed that tested EOs produce structural alteration in cell wall component deposition, decreasing the hypha width. Moreover, propidium iodide and Calcein-AM stains evidenced the loss of membrane integrity and reduced cell viability of fungi treated with EOs. Fungi treated with EOs decreased the mitochondria activity and the respiratory process. Therefore, these EOs are effective antifungal agents against B. cinerea and P. expansum, which is attributed to changes in the cell wall structure, the breakdown of the cell membrane, and the alteration of the mitochondrial activity.

A combinatorial approach of Monarda citriodora essential oil (MEO) and linalool vapors to control fruit rot of Citrus limon caused by a new pathogen, Aspergillus foetidus, and its underlying mode of action

AIMS

Citrus limon (lemon) is a widely cultivated citrus fruit. Significant postharvest losses due to fungi plague its production. Environmental and human health hazards have made the application of synthetic fungicides unsuitable. Despite the previous reports of antifungal activities of essential oil (EO) vapors, their synergistic combinations are understudied. Synergistic vapor combinations are advantageous due to less concentration of active components. This study aimed to isolate and identify postharvest fungal pathogens lemon and to evaluate the antifungal effects of synergistic Monarda citriodora EO (MEO)-constituent vapor combinations in vivo and in vitro.

METHODS AND RESULTS

Postharvest fungal pathogens of lemon (C. limon) were isolated from various infected samples. The most pathogenic isolate was identified through morphology and its ITS-based rRNA gene sequencing as Aspergillus foetidus (O4). This is the first report of A. foetidus as a postharvest pathogen of lemon. The minimum fungicidal concentrations (MFCs) of MEO vapors treatment against O4 were 1346.15 µL/L air. For carvacrol, hexanal, and linalool, MFC was same (96.16 µL/L air). Checkerboard assays demonstrated that 1/4 MFC of MEO (336.54 µL/L air) and 1/4 MFC of linalool (24.04 µL/L air) (M + L) were synergistic against O4. M + L vapors reduced the O4 growth on lemons during storage by 64% ± 1.50% and preserved their quality (low weight loss %, unchanged pH, increased ascorbic acid content). Propidium iodide staining, ergosterol content analysis, calcofluor white staining and chitin content analysis revealed the integrity loss of the O4 plasma membrane and cell wall. 2',7'-Dichlorofluorescin diacetate staining revealed accumulation of intracellular reactive oxygen species (ROS), and scanning electron microscopy (SEM) analysis exposed the M + L treated mycelia with malformations.

CONCLUSIONS

M + L vapors offer protection for lemons from A. foetidus and preserve their quality during storage.

Chemical Composition and Antimicrobial Activity against the Listeria monocytogenes of Essential Oils from Seven Salvia Species

In recent years, essential oils (EOs) have received interest due to their antibacterial properties. Accordingly, the present study aimed to investigate the effectiveness of the EOs obtained from seven species of Salvia on three strains of Listeria monocytogenes (two serotyped wild strains and one ATCC strain), a bacterium able to contaminate food products and cause foodborne disease in humans. The Salvia species analysed in the present study were cultivated at the Botanic Garden and Museum of the University of Pisa, and their air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus. The obtained EOs were analysed via gas chromatography coupled with mass spectrometry for the evaluation of their chemical composition, and they were tested for their inhibitory and bactericidal activities by means of MIC and MBC. The tested Eos showed promising results, and the best outcomes were reached by S. chamaedryoides EO, showing an MIC of 1:256 and an MBC of 1:64. The predominant compounds of this EO were the sesquiterpenes caryophyllene oxide and β-caryophyllene, together with the monoterpenes bornyl acetate and borneol. These results suggest that these EOs may possibly be used in the food industry as preservatives of natural origins.

Eucalyptus camaldulensis Dehnh Leaf Essential Oil from Palestine Exhibits Antimicrobial and Antioxidant Activity but No Effect on Porcine Pancreatic Lipase and α-Amylase

Eucalyptus camaldulensis Dehnh is a tree species that is commonly used for various purposes, including forestry, agroforestry, and conservation. The present investigation was designed to determine the composition of E. camaldulensis leaves essential oil and estimate its free radicals, porcine pancreatic lipase, α-amylase inhibitory, and antimicrobial properties in vitro. The chemical constituents were analyzed using the gas chromatography-mass spectrometry (GC-MS) technique. DPPH (2,2-diphenyl-1-picrylhydrazyl), p-nitrophenyl butyrate, and 3,5-dinitro salicylic acid (DNSA) methods were employed to estimate the antioxidant, antiobesity, and antidiabetic effects of the essential oil. The microdilution assay was employed to assess the antimicrobial efficacy of the substance against a total of seven distinct microbial species. The GC-MS results revealed that E. camaldulensis essential oil contains 52 components that makeup 100% of the entire oil. The main chemical constituents in E. camaldulensis essential oil are p-cymene (38.64%), followed by aromadendrene (29.65%), and 1,8-cineol (6.45%), with monocyclic monoterpene being the most abundant phytochemical group, followed by the sesquiterpene hydrocarbon group, representing 44.27 and 31.46%, respectively. The essential oil showed a weak antioxidant effect and had no antilipase or antiamylase effects. At the same time, the oil showed a strong antimicrobial effect against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, and Proteus vulgaris, which was even more potent than the positive controls, ciprofloxacin and ampicillin, which had MIC doses of 0.2 ± 0.01, 0.2 ± 0.01, and 6.25 ± 0.1 µg/mL, respectively. It also has a strong anti-Candida albicans effect with a MIC of 0.2 ± 0.01 µg/mL. In light of these findings, in vivo studies should be conducted to determine the efficiency of the E. camaldulensis essential oil in treating microbial infections.

Advances in Designing Essential Oil Nanoformulations: An Integrative Approach to Mathematical Modeling with Potential Application in Food Preservation

Preservation of foods, along with health and safety issues, is a growing concern in the current generation. Essential oils have emerged as a natural means for the long-term protection of foods along with the maintenance of their qualities. Direct applications of essential oils have posed various constraints to the food system and also have limitations in application; hence, encapsulation of essential oils into biopolymers has been recognized as a cutting-edge technology to overcome these challenges. This article presents and evaluates the strategies for the development of encapsulated essential oils on the basis of fascination with the modeling and shuffling of various biopolymers, surfactants, and co-surfactants, along with the utilization of different fabrication processes. Artificial intelligence and machine learning have enabled the preparation of different nanoemulsion formulations, synthesis strategies, stability, and release kinetics of essential oils or their bioactive components from nanoemulsions with improved efficacy in food systems. Different mathematical models for the stability and delivery kinetics of essential oils in food systems have also been discussed. The article also explains the advanced application of modeling-based encapsulation strategies on the preservation of a variety of food commodities with their intended implication in food and agricultural industries.

Advances in efficient extraction of essential oils from spices and its application in food industry: A critical review

With the increase of people's awareness of food safety, it is crucial to find natural and green antimicrobial agents to replace traditional antimicrobial agents. Essential oils of spices (SEOs) are low toxicity or nontoxic, which exhibited antioxidants and antimicrobial activity according to many in vitro and in situ experiments. Spices are widely available and low cost as a plant raw material for the extraction of SEOs. This review summarized highly efficient extraction techniques for SEOs, such as physical field assisted extraction technology, supercritical fluid extraction, and biological-based techniques. Furthermore, purification of SEOs and components were also recapitulated. Purification techniques of SEOs improve their utilization value due to the increased content of bioactive components. Finally, the review concentrated on the applications of SEOs in food industry, including food preservation, food active packaging by means of films or coatings, antioxidant properties. In addition, addressing the problem of unstability of SEOs and its role to inhibit the pathogenic bacteria, the encapsulation of SEOs for use in the food industrial sectors reduces the safety risk to human health.

Unveiling the volatile compounds and antibacterial mechanisms of action of Cupressus sempervirens L., against Bacillus subtilis and Pseudomonas aeruginosa

Cupressus sempervirens is a known traditional plant used to manage various ailments, including cancer, inflammatory and infectious diseases. In this investigation, we aimed to explore the chemical profile of Cupressus sempervirens essential oil (CSEO) as well as their antibacterial mode of action. The volatile components were characterized using gas chromatography coupled to a mass spectrometer (GC-MS). The results revealed remarkable antibacterial properties of EO derived from C. sempervirens. GC-MS analysis indicated that C. sempervirens EO characterized by δ-3-carene (47.72%), D-limonene (5.44%), β-pinene (4.36%), β-myrcene (4.02%). The oil exhibited significant inhibitory effects against a range of bacteria, including Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 13048, Bacillus cereus (Clinical isolate), Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. These inhibitory effects surpassed those of conventional antibiotics. Furthermore, the EO demonstrated low minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs), indicating its bactericidal nature (MBC/MIC < 4.0). Time-kill kinetics analysis showed that CSEO was particularly effective at 2 × MIC doses, rapidly reduced viable count of B. subtilis and P. aeruginosa within 8 h. This suggests that the oil acts quickly and efficiently. The cell membrane permeability test further demonstrated the impact of CSEO on the relative conductivity of B. subtilis and P. aeruginosa, both at 2 × MIC concentrations. These observations suggest that EO disrupts the bacterial membrane, thereby influencing their growth and viability. Additionally, the cell membrane integrity test indicated that the addition of CSEO to bacterial cultures resulted in the significant release of proteins from the bacterial cells. This suggests that EO affects the structural integrity of the bacterial cells. Furthermore, the anti-biofilm assay confirmed the efficacy of CSEO as a potent anti-biofilm agent. It demonstrated the oil's ability to inhibit quorum sensing, a crucial mechanism for biofilm formation, and its competitive performance compared to the tested antibiotics.

Current status, technology, regulation and future perspectives of essential oils usage in the food and drink industry

Nowadays, essential oils (EOs) have a wide use in many applications such as in food, cosmetics, pharmaceutical and animal feed products. Consumers' preferences concerning healthier and safer foodstuffs lead to an increased demand for natural products, in replacement of synthetic substances, used as preservatives, flavourings etc. EOs, besides being safe, are promising alternatives as natural food additives, and much research has been carried out on their antioxidant and antimicrobial activity. The initial purpose of this review is to discuss conventional and 'green' extraction techniques along with their basic mechanism for the isolation of EOs from aromatic plants. This review aims to provide a broad overview of the current knowledge about the chemical constitution of EOs while considering the existence of different chemotypes, since bioactivity is attributed to the chemical composition - qualitative and quantitative - of EOs. Although the food industry primarily uses EOs as flavourings, an overview on recent applications of EOs in food systems and active packaging is provided. EOs exhibit poor solubility in water, oxidation susceptibility, negative organoleptic effect and volatility, restricting their use. Encapsulation techniques have been proven to be one of the best approaches to preserve the biological activities of EOs and minimize their effects on food sensory qualities. Herein, different encapsulation techniques and their basic mechanism for loading EOs are discussed. EOs are highly accepted by consumers, who are often under the misconception that 'natural' means safe. This is, however, an oversimplification, and the possible toxicity of EOs should be taken into consideration. Thus, in the final section of the current review, the focus is on current EU legislation, safety assessment and sensory evaluation of EOs. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Synergistic Effects of Essential Oils and Organic Acids against Aspergillus flavus Contamination in Poultry Feed

Organic acids and essential oils are commonly used in the poultry industry as antimicrobials and for their beneficial effects on gut health, growth performance, and meat quality. A common postharvest storage fungal colonist, Aspergillus flavus, contaminates corn, the primary component of poultry feed, with the highly detrimental mycotoxin, aflatoxin. Aflatoxin adversely affects poultry feed intake, feed conversion efficiency, weight gain, egg production, fertility, hatchability, and poultry meat yield. Both organic acids and essential oils have been reported to inhibit the growth of A. flavus. Thus, we evaluated if the inhibitory synergy between combined essential oils (cinnamon, lemongrass, and oregano) and organic acids (acetic, butyric, and propionic) prevents A. flavus growth. The study confirmed that these compounds inhibit the growth of A. flavus and that synergistic interactions do occur between some of them. Overall, cinnamon oil was shown to have the highest synergy with all the organic acids tested, requiring 1000 µL/L air of cinnamon oil and 888 mg/kg of butyric acid to fully suppress A. flavus growth on corn kernels. With the strong synergism demonstrated, combining certain essential oils and organic acids offers a potentially effective natural method for controlling postharvest aflatoxin contamination in poultry feed.

Identification of the chemical profile and evaluation of the antimicrobial effect of Eryngium billardieri Delar essential oil component against bacterial species of agricultural and food interest

Studies on the antibacterial activity of the essential oil of E. billardieri are limited. In this study, we identified this herb as a natural complex effective against several bacteria by employing disk diffusion and broth microdilution susceptibility methods. Primary estimation of the antimicrobial effect of this herbal compound by disk diffusion method showed that the oil could inhibit the growth of the tested bacteria by the appearance of haloes between 8.25 and 21.25 mm. In the next step, the oil was found to be active against all 24 tested Gram-negative and Gram-positive bacteria in the broth media, at minimum inhibitory concentrations ranging from 0.67 to 34.17 g L-1. Furthermore, Enterococcus faecalis and Curtobacterium flaccumfaciens pv. flaccumfaciens were the most sensitive food and plant pathogenic bacteria, respectively. Gas chromatography-mass spectrometry analysis was conducted to assign the ingredients present in the oil; 34 different components representing 95.71% of the total oil were identified, with n-hexadecanoic acid being the dominant component, followed by 2-Pentadecanone, 6,10,14-trimethyl, 1H-Indene, 1-ethylideneoctahydro-, and Cinnamyl tiglate. These findings demonstrate, for the first time, a broad spectrum of the antibacterial capacity of E. billardieri. Based on these observations, the oil could be applied as a natural preservative with the potential for designing novel products. Its bioactive agents can also be isolated for further use in the food and agricultural industries.

Recent Trends in Active Packaging Using Nanotechnology to Inhibit Oxidation and Microbiological Growth in Muscle Foods

Muscle foods are highly perishable products that require the use of additives to inhibit lipid and protein oxidation and/or the growth of spoilage and pathogenic microorganisms. The reduction or replacement of additives used in the food industry is a current trend that requires the support of active-packaging technology to overcome novel challenges in muscle-food preservation. Several nano-sized active substances incorporated in the polymeric matrix of muscle-food packaging were discussed (nanocarriers and nanoparticles of essential oils, metal oxide, extracts, enzymes, bioactive peptides, surfactants, and bacteriophages). In addition, the extension of the shelf life and the inhibitory effects of oxidation and microbial growth obtained during storage were also extensively revised. The use of active packaging in muscle foods to inhibit oxidation and microbial growth is an alternative in the development of clean-label meat and meat products. Although the studies presented serve as a basis for future research, it is important to emphasize the importance of carrying out detailed studies of the possible migration of potentially toxic additives, incorporated in active packaging developed for muscle foods under different storage conditions.

Antimicrobial Effects and Antioxidant Activity of Myrtus communis L. Essential Oil in Beef Stored under Different Packaging Conditions

The aim of this study was to assess the antimicrobial effects of myrtle (Myrtus communis L.) essential oil (EO) on pathogenic (E. coli O157:H7 NCTC 12900; Listeria monocytogenes ATCC BAA-679) and spoilage microbiota in beef and determine its minimum inhibitory concentration (MIC) and antioxidant activity. The behavior of LAB, Enterobacteriaceae, Pseudomonas spp., and fungi, as well as total mesophilic (TM) and total psychotropic (TP) counts, in beef samples, was analyzed during storage at 2 and 8 °C in two different packaging systems (aerobiosis and vacuum). Leaves of myrtle were dried, its EO was extracted by hydrodistillation using a Clevenger-type apparatus, and the chemical composition was determined using chromatographical techniques. The major compounds obtained were myrtenyl acetate (15.5%), β-linalool (12.3%), 1,8-cineole (eucalyptol; 9.9%), geranyl acetate (7.4%), limonene (6.2%), α-pinene (4.4%), linalyl o-aminobenzoate (5.8%), α-terpineol (2.7%), and myrtenol (1.2%). Myrtle EO presented a MIC of 25 µL/mL for E. coli O157:H7 NCTC 12900, E. coli, Listeria monocytogenes ATCC BAA-679, Enterobacteriaceae, and E. coli O157:H7 ATCC 35150 and 50µL/mL for Pseudomonas spp. The samples packed in aerobiosis had higher counts of deteriorative microorganisms than samples packed under vacuum, and samples with myrtle EO presented the lowest microbial contents, indicating good antimicrobial activity in beef samples. Myrtle EO is a viable natural alternative to eliminate or reduce the pathogenic and deteriorative microorganisms of meat, preventing their growth and enhancing meat safety.

Antibacterial activity and mechanism of cinnamon essential oil nanoemulsion against Pseudomonas deceptionensis CM2

This work aimed to evaluate the antibacterial activity and mechanism of cinnamon essential oil nanoemulsion (CON) against Pseudomonas deceptionensis CM2. The results revealed that CON could effectively inhibit the proliferation of P. deceptionensis CM2 cells in a time- and concentration-dependent manner. After 4 h of incubation with CON at the minimum inhibitory concentration (0.125 mg/mL), the relative fluorescence intensity of propidium iodide and 1-N-phenylnapthylamine (NPN) was increased by 32.0% and 351.4%, respectively. The membrane permeability of P. deceptionensis CM2 cells was significantly disrupted after CON treatment, resulting in the leakage of intracellular substances (such as proteins and electrolytes). CON also caused significant increases in the DiBAC4(3) fluorescence intensity of P. deceptionensis CM2 cells. These results demonstrate that CON induced inactivation of P. deceptionensis CM2 by destroying the integrity and function of bacterial membrane. A higher level of intracellular reactive oxygen species (ROS) was observed in CON-treated cells (p < 0.05), compared with control cells. Moreover, the addition of glutathione to the growth medium remarkably decreased the antimicrobial activity of CON against P. deceptionensis CM2, further confirming that oxidative stress played an important role in the antimicrobial activity of CON. Overall, CON may exhibit antibacterial effects by causing damage to the bacterial membranes and oxidative stress.

Essential Oils and Their Combination with Lactic Acid Bacteria and Bacteriocins to Improve the Safety and Shelf Life of Foods: A Review

The use of plant extracts (e.g., essential oils and their active compounds) represents an interesting alternative to chemical additives and preservatives applied to delay the alteration and oxidation of foods during their storage. Essential oils (EO) are nowadays considered valuable sources of food preservatives as they provide a healthier alternative to synthetic chemicals while serving the same purpose without affecting food quality parameters. The natural antimicrobial molecules found in medicinal plants represent a possible solution against drug-resistant bacteria, which represent a global health problem, especially for foodborne infections. Several solutions related to their application on food have been described, such as incorporation in active packaging or edible film and direct encapsulation. However, the use of bioactive concentrations of plant derivatives may negatively impact the sensorial characteristics of the final product, and to solve this problem, their application has been proposed in combination with other hurdles, including biocontrol agents. Biocontrol agents are microbial cultures capable of producing natural antimicrobials, including bacteriocins, organic acids, volatile organic compounds, and hydrolytic enzymes. The major effect of bacteriocins or bacteriocin-producing LAB (lactic acid bacteria) on food is obtained when their use is combined with other preservation methods. The combined use of EOs and biocontrol agents in fruit and vegetables, meat, and dairy products is becoming more and more important due to growing concerns about potentially dangerous and toxic synthetic additives. The combination of these two hurdles can improve the safety and shelf life (inactivation of spoilage or pathogenic microorganisms) of the final products while maintaining or stabilizing their sensory and nutritional quality. This review critically describes and collects the most updated works regarding the application of EOs in different food sectors and their combination with biocontrol agents and bacteriocins.

Analysis of the Effect of Various Potential Antimicrobial Agents on the Quality of the Unpasteurized Carrot Juice

Short shelf-life and poor microbial quality of minimally processed foods of plant origin pose a serious problem for the food industry. Novel techniques of minimal treatment combined with disinfection are being researched, and, for fresh juice, the addition of antimicrobial agents appears to be a promising route. In this research, fresh, nonfiltered, unpasteurized carrot juice was mixed with four potential antimicrobials (bourbon vanilla extract, peppermint extract, cannabidiol oil, and grapefruit extract). All four variants and the reference pure carrot juice were analyzed for metapopulational changes, microbial changes, and physicochemical changes. The potential antimicrobials used in the research have improved the overall microbial quality of carrot juice across 4 days of storage. However, it is important to notice that each of the four agents had a different spectrum of effectiveness towards the groups identified in the microflora of carrot juice. Additionally, the antimicrobials have increased the diversity of the carrot juice microbiome but did not prevent the occurrence of pathogenic bacteria. In conclusion, the use of antimicrobial agents such as essential oils or their derivatives may be a promising way of improving the microbial quality and prolonging the shelf-life of minimally processed foods, such as fresh juices, but the technique requires further research.

Antibacterial activity of Thymus vulgaris (thyme) essential oil against strains of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus saprophyticus isolated from meat product

Meat products represent an important component of the human diet and are a good source of nutrients. Food-borne microorganisms are the main pathogens that cause human diseases as a result of food consumption, especially products of animal origin. The objective of the present research was to verify the antibacterial activity of the essential oil of Thymus vulgaris against strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus saprophyticus isolated from meat products. For this, the analyses of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were performed in microdilution plates. The association of the product with antimicrobials was also studied using disk diffusion. And the anti-adherent activity, which was determined in the presence of sucrose, in glass tubes. Thyme oil showed a strong inhibitory activity against K. pneumoniae, P. aeruginosa and S. saprophyticus, with the MIC values ranging from 64 to 512 μg/mL, and bactericidal effect for most strains, with MBC values ranging from 256 to 1,024 μg/mL. T. vulgaris oil exhibited varied interactions in association with the antimicrobials, with synergistic (41.67%), indifferent (50%) and antagonistic (8.33%) effects. Regarding the anti-adherent activity, the test product was effective in inhibiting the adherence of all bacterial strains under study. Therefore, thyme oil presents itself as an antibacterial and anti-adherent agent against K. pneumoniae, P. aeruginosa and S. saprophyticus, being a natural product that can represent an interesting alternative in the efforts to combat foodborne diseases.

Stimulation of the Defense Mechanisms of Potatoes to a Late Blight Causative Agent When Treated with Bacillus subtilis Bacteria and Chitosan Composites with Hydroxycinnamic Acids

Phytophthora infestans is, worldwide, one of the main causal agents of epiphytotics in potato plantings. Prevention strategies demand integrated pest management, including modeling of beneficial microbiomes of agroecosystems combining microorganisms and natural products. Chitooligosaccharides and their derivatives have great potential to be used by agrotechnology due to their ability to elicit plant immune reactions. The effect of combining Bacillus subtilis 26D and 11VM and conjugates of chitin with hydroxycinnamates on late blight pathogenesis was evaluated. Mechanisms for increasing the resistance of potato plants to Phytophthora infestans were associated with the activation of the antioxidant system of plants and an increase in the level of gene transcripts that encode PR proteins: basic protective protein (PR-1), thaumatin-like protein (PR-5), protease inhibitor (PR-6), and peroxidase (PR-9). The revealed activation of the expression of marker genes of systemic acquired resistance and induced systemic resistance under the influence of the combined treatment of plants with B. subtilis and conjugates of chitin with hydroxycinnamates indicates that, in this case, the development of protective reactions in potato plants to late blight proceeds synergistically, where B. subtilis primes protective genes, and chitosan composites act as a trigger for their expression.

Essential oil encapsulation by electrospinning and electrospraying using food proteins: A review

Proteins are excellent polymeric materials for encapsulating essential oils (EOs) by electrospinning and electrospraying to protect these compounds and form nanomaterials with active properties. Proteins can encapsulate bioactive molecules by several mechanisms, including surface activity, absorption and stabilization mechanisms, amphiphilic nature, film-forming capacity, foaming, emulsification, and gelation, due to interactions among their functional groups. However, proteins have some limitations in encapsulating EOs by the electrohydrodynamic process. Their properties can be improved by using auxiliary polymers, increasing their charges by adding ionic salts or polyelectrolytes, denaturing their structure by heat, and exposure to specific pH conditions and ionic strength. This review addresses the main proteins used in electrospinning/electrospraying techniques, production methods, their interactions with EOs, bioactive properties, and applications in food matrices. Multivariate analysis associated with bibliometrics of metadata extracted from studies in Web of Science using the keywords electrospinning and essential oil (EO) were used as the search strategy.

Experimental Evolution Reveals a Novel Ene Reductase That Detoxifies α,β-Unsaturated Aldehydes in Listeria monocytogenes

The plant essential oil component trans-cinnamaldehyde (t-CIN) exhibits antibacterial activity against a broad range of foodborne pathogenic bacteria, including L. monocytogenes, but its mode of action is not fully understood. In this study, several independent mutants of L. monocytogenes with increased t-CIN tolerance were obtained via experimental evolution. Whole-genome sequencing (WGS) analysis revealed single-nucleotide-variation mutations in the yhfK gene, encoding an oxidoreductase of the short-chain dehydrogenases/reductases superfamily, in each mutant. The deletion of yhfK conferred increased sensitivity to t-CIN and several other α,β-unsaturated aldehydes, including trans-2-hexenal, citral, and 4-hydroxy-2-nonenal. The t-CIN tolerance of the deletion mutant was restored via genetic complementation with yhfK. Based on a gas chromatography-mass spectrometry (GC-MS) analysis of the culture supernatants, it is proposed that YhfK is an ene reductase that converts t-CIN to 3-phenylpropanal by reducing the C=C double bond of the α,β-unsaturated aldehyde moiety. YhfK homologs are widely distributed in Bacteria, and the deletion of the corresponding homolog in Bacillus subtilis also caused increased sensitivity to t-CIN and trans-2-hexenal, suggesting that this protein may have a conserved function to protect bacteria against toxic α,β-unsaturated aldehydes in their environments. IMPORTANCE While bacterial resistance against clinically used antibiotics has been well studied, less is known about resistance against other antimicrobials, such as natural compounds that could replace traditional food preservatives. In this work, we report that the food pathogen Listeria monocytogenes can rapidly develop an elevated tolerance against t-cinnamaldehyde, a natural antimicrobial from cinnamon, by single base pair changes in the yhfK gene. The enzyme encoded by this gene is an oxidoreductase, but its substrates and precise role were hitherto unknown. We demonstrate that the enzyme reduces the double bond in t-cinnamaldehyde and thereby abolishes its antibacterial activity. Furthermore, the mutations linked to t-CIN tolerance increased bacterial sensitivity to a related compound, suggesting that they modify the substrate specificity of the enzyme. Since the family of oxidoreductases to which YhfK belongs is of great interest in the mediation of stereospecific reactions in biocatalysis, our work may also have unanticipated application potential in this field.

Comparing the effects of essential oils and methanolic extracts on the inhibition of Aspergillus flavus and Aspergillus parasiticus growth and production of aflatoxins

The antifungal and antiaflatoxigenic effects of four distinct plant species against Aspergillus flavus and Aspergillus parasiticus were investigated. Essential oils and methanolic extracts were prepared from aerial parts of Lippia javanica, Ocimum gratissimum, Satureja punctata, and stem barks of Toddalia asiatica by hydro-distillation and maceration, respectively. The poisoned food method was used to confirm the antifungal activity of essential oils and methanolic extracts from four different plant species against Aspergillus flavus and Aspergillus parasiticus, and high-performance liquid chromatography was used to quantify the antiaflatoxigenic activity. The essential oils of Satureja punctata and Lippia javanica showed the highest antiaflatoxigenic activity against the fungi strains tested at concentrations of 1.25, 2.5, and 5 µL/mL, followed by Ocimum gratissimum essential oil while Toddalia asiatica essential oil exerted moderate antiaflatoxigenic activity. Meanwhile, the methanolic extracts showed a wide spectrum of low to high antifungal and antiaflatoxigenic activities at concentrations of 125, 250, and 500 µg/mL against A. flavus and A. parasiticus. This study has indicated that the essential oils of Satureja punctate, Lippia javanica, and Ocimum gratissimum had substantial antifungal and antiaflatoxigenic activities compared to their methanolic extracts, while Toddalia asiatica methanolic extract had a moderate antifungal activity compared to its essential oil.

Comparative Virucidal Activities of Essential Oils and Alcohol-Based Solutions against Enveloped Virus Surrogates: In Vitro and In Silico Analyses

The large-scale use of alcohol (OH)-based disinfectants to control pathogenic viruses is of great concern because of their side effects on humans and harmful impact on the environment. There is an urgent need to develop safe and environmentally friendly disinfectants. Essential oils (EOs) are generally recognized as safe (GRAS) by the FDA, and many exhibit strong antiviral efficacy against pathogenic human enveloped viruses. The present study investigated the virucidal disinfectant activity of solutions containing EO and OH against DENV-2 and CHIKV, which were used as surrogate viruses for human pathogenic enveloped viruses. The quantitative suspension test was used. A solution containing 12% EO + 10% OH reduced > 4.0 log10 TCID₅₀ (100% reduction) of both viruses within 1 min of exposure. In addition, solutions containing 12% EO and 3% EO without OH reduced > 4.0 log10 TCID₅₀ of both viruses after 10 min and 30 min of exposure, respectively. The binding affinities of 42 EO compounds and viral envelope proteins were investigated through docking analyses. Sesquiterpene showed the highest binding affinities (from -6.7 to -8.0 kcal/mol) with DENV-2 E and CHIKV E1-E2-E3 proteins. The data provide a first step toward defining the potential of EOs as disinfectants.

Application of essential oils as sanitizer alternatives on the postharvest washing of fresh produce

Growers commonly wash fresh produce with chemical sanitizers during postharvest handling. However, these sanitizers can be harsh to washing systems and pose a health risk to workers. Essential oils (EOs) can be used as alternatives to chemical sanitizers in produce washing. Previous studies reveal that the EOs from thyme, oregano, cinnamon, and clove are the main EOs evaluated in the studies as potential sanitizers for the washing of produce. The use of EOs and surfactants, such as tween80 and cetylpyridinium chloride, might be used to improve the antimicrobial activity of emulsions. However, studies are still required to evaluate the potential effect of different chemical components of EOs and preparations. Also, it is recommended that researchers focus on overcoming obstacles regarding EOs application in washing systems, including the high levels of EO required to reduce bacterial growth, undesired organoleptic impact on produce, and the poor solubility of EOs in aqueous solution.

Surface Disinfection and Sanitizing Action of the Alcohol-Free Essential Oil-based Green Formulation

The surface disinfectant property of a prepared formulation using potential and effective EO (Murraya koenigii), phytochemical (Geraniol), and an amino acid epsilon-L-Poly-Lysine (ɛ-PL) is examined in this present study. To investigate its potential as a surface disinfectant (SD) different tests using multiple bacterial strains were conducted. All tested bacterial strains were inhibited by the SD treatments, with a MIC range of (0.78-3.12%) v/v. Notably, Staphylococcus sp. was found to be more susceptible to the treatment than its gram-negative counterparts. In the test, sterile stainless-steel surfaces were used and externally contaminated with Escherichia sp. Cleaning the surface with the prepared formulation was more effective than the equal concentration of vinegar in terms of bacterial growth reduction. Vinegar was used as a mother solvent in the preparation of the SD due to its proven antibacterial effect. It is worth mentioning, this formulation is also proven to be effective on biofilm-embedded bacterial cells of Pseudomonas aeruginosa PAO1 as found in epifluorescence microscopy staining. Even though the impact of each constituent needs to be further explored, the effectiveness of this formulation may encourage large farms to seek out alternatives that are more environmentally friendly, safe, and effective than conventional products.

Sensory acceptability of antioxidant-based formulations dedicated to mitigate heterocyclic aromatic amines in cooked meat

In a previous work, we studied the inhibition of heterocyclic aromatic amine formation by natural ingredients rich in antioxidants: caper, oregano, wine and green tea. This present work aimed to assess the sensory impact of the addition of these ingredients in ground beef patties. The best liked formulations were determined by a hedonic scoring. Caper and oregano were not significantly different from the standard, the most appreciated, due to their congruency with cooked meat. Direct dissimilarity assessment was performed to evaluate the overall, gustative and odor differences between formulations. Olfactive differences were evidenced as key drivers of these differences. Standard and caper were close while oregano was found significantly different from them. A fast sensory profiling permitted to evidence that aromatic plant note was discriminant for oregano formulation. Gas chromatography-mass spectrometry/multibooth olfactometry identified the distinctive odor-active compounds of the formulations as pyrazines and sulfide for oregano formulation and ester for caper formulation.

Chitosan based encapsulation of Valeriana officinalis essential oil as edible coating for inhibition of fungi and aflatoxin B1 contamination, nutritional quality improvement, and shelf life extension of Citrus sinensis fruits

In this study, a novel chitosan nanoemulsion coating embedded with Valeriana officinalis essential oil (Ne-VOEO) was synthesized in order to improve the postharvest quality of Citrus sinensis fruits against infesting fungi, and aflatoxin B₁ (AFB₁) mediated nutritional deterioration. The developed nanoemulsion was characterized through SEM, FTIR, XRD, and DLS analyses. The nanoemulsion showed controlled delivery of VOEO responsible for effective inhibition of Aspergillus flavus, A. niger, A. versicolor, Penicillium italicum, and Fusarium oxysporum growth at 6.5, 5.0, 4.0, 5.5, and 3.5 μL/mL, respectively and AFB₁ production at 5.0 μL/mL. The biochemical and molecular mechanism of aflatoxigenic A. flavus inhibition, and AFB₁ diminution was associated with impairment in ergosterol biosynthesis, methylglyoxal production, and stereo-spatial binding of valerianol in the cavity of Ver-1 protein. During in vivo investigation, Ne-VOEO coating potentially restrained the weight loss, and respiratory rate of C. sinensis fruits with delayed degradation of soluble solids, titrable acidity, pH, and phenolic contents along with maintenance of SOD, CAT, APX activities (p < 0.05) and sensory attributes under specific storage conditions. Based on overall findings, Ne-VOEO nanoemulsion could be recommended as green, and smart antifungal coating agent in prolonging the shelf-life of stored fruits with enhanced AFB₁ mitigation.

Unraveling the Variability of Essential Oil Composition in Different Accessions of Bunium persicum Collected from Different Temperate Micro-Climates

The present investigation was performed to evaluate the variability of the essential oil composition present in the seed extract of Kala zeera (Bunium persicum Bioss.) obtained from different geographical zones of Northwestern-Himalayan using Gas Chromatography-Mass Spectrum (GC-MS). The results of the GC-MS analysis revealed significant differences in the essential oil content. Significant variability was observed in the chemical constituents of the essential oils mainly for p-cymene, D-limonene, Gamma-terpinene, Cumic aldehyde and 1, 4-p-menthadien-7-al. Among these compounds, the highest average percentage across the locations was observed for gamma-terpinene (32.08%) which was followed by cumic aldehyde (25.07%), and 1, 4-p-menthadien-7-al (15.45%). Principal component analysis (PCA) also grouped the 4 highly significant compounds i.e., p-Cymene, Gamma-Terpinene, Cumic aldehyde, and 1,4-p-Menthadien-7-al into same cluster which are mainly distributed in Shalimar Kalazeera-1, and Atholi Kishtwar zones. The highest value of gamma-terpinene was recorded in Atholi accession (40.66%). However, among climatic zones Zabarwan Srinagar and Shalimar Kalazeera-1 was found to have highly positive significant correlation (0.99). The cophenetic correlation coefficient (c) was found to be 0.8334 during hierarchical clustering for 12 essential oil compounds showing that our results are highly correlated. Network analysis also showed the overlapping pattern and similar interaction between the 12 compounds as shown by hierarchical clustering analysis. From the results, it could be concluded that existence of variability among the various bioactive compounds of B. persicum which are probably to be incorporated to the potential list of drugs and may serve as good genetic source for various modern breeding programs.

Quorum-quenching enzymes: Promising bioresources and their opportunities and challenges as alternative bacteriostatic agents in food industry

The problems of spoilage, disease, and biofilm caused by bacterial quorum-sensing (QS) systems have posed a significant challenge to the development of the food industry. Quorum-quenching (QQ) enzymes can block QS by hydrolyzing or modifying the signal molecule, making these enzymes promising new candidates for use as antimicrobials. With many recent studies of QQ enzymes and their potential to target foodborne bacteria, an updated and systematic review is necessary. Thus, the goals of this review were to summarize what is known about the effects of bacterial QS on the food industry; discuss the current understanding of the catalytic mechanisms of QQ enzymes, including lactonase, acylase, and oxidoreductase; and describe strategies for the engineering and evolution of QQ enzymes for practical use. In particular, this review focuses on the latest progress in the application of QQ enzymes in the field of food. Finally, the current challenges limiting the systematic application of QQ enzymes in the food industry are discussed to help guide the future development of these important enzymes.

Exploring fennel (Foeniculum vulgare): Composition, functional properties, potential health benefits, and safety

Fennel (Foeniculum vulgare Mill), a member of the Apiaceae family (Umbelliferaceae), is a hardy and perennial herb, with grooved stems, intermittent leaves, petiole with sheath, usually bisexual flower and yellow umbrella. Although fennel is a typical aromatic plant generally considered native to the Mediterranean shores, it has become widespread in many regions of the world and has long been used as a medicinal and culinary herb. The aim of this review is to collect recent information from the literature on the chemical composition, functional properties and toxicology of fennel. Collected data show the efficacy of this plant in various in vitro and in vivo pharmacological studies including antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory, antimutagenic, antinociceptive, hepatoprotective, bronchodilatory, and memory enhancing activities. It has also been shown to be effective on infantile colic, dysmenorrhea, polycystic ovarian syndrome and milk production. This review also aims to identify gaps in the literature that require to be filled by future research.

Basic sensory properties of essential oils from aromatic plants and their applications: a critical review

With higher standards in terms of diet and leisure enjoyment, spices and essential oils of aromatic plants (APEOs) are no longer confined to the food industry. The essential oils (EOs) produced from them are the active ingredients that contribute to different flavors. The multiple odor sensory properties and their taste characteristics of APEOs are responsible for their widespread use. The research on the flavor of APEOs is an evolving process attracting the attention among scientists in the past decades. For APEOs, which are used for a long time in the catering and leisure industries, it is necessary to analyze the components associated with the aromas and the tastes. It is important to identify the volatile components and assure quality of APEOs in order to expand their application. It is worth celebrating the different means by which the loss of flavor of APEOs can be retarded in practice. Unfortunately, relatively little research has been done on the structure and flavor mechanisms of APEOs. This also points the way to future research on APEOs.Therefore, this paper reviews the principles of flavor, identification of components and sensory pathways in humans for APEOs. Moreover, the article outlines the means of increasing the efficiency of using of APEOs. Finally, with respect to the sensory applications of APEOs, the review focuses on the practical application of APEOs in food sector and in aromatherapy.

The Assessment of Antimicrobial and Anti-Biofilm Activity of Essential Oils against Staphylococcus aureus Strains

The increase in antimicrobial resistance and tolerance over the years has become a serious public health problem, leading to the inevitable development of alternative antimicrobial agents as substitutes for industrial pharmaceutical antibiotics targeting humans and animals under the concept of one health. Essential oils (EOs) extracted from aromatic and pharmaceutical plants incorporate several bioactive compounds (phytochemicals) that positively affect human and animal health. Herein, this work aimed to examine a standardized chemical composition and screen the antimicrobial and anti-biofilm activity of Thymus sibthorpii, Origanum vulgare, Salvia fruticosa, and Crithmum maritimum EOs against three different Staphylococcus aureus strains by gold-standard disc diffusion, broth microdilution, and microtiter plate biofilm assays. Therefore, the evaluation of the above-mentioned EOs were considered as substitutes for antibiotics to combat the ever-mounting antimicrobial resistance problem. The observed bacterial growth inhibition varied significantly depending on the type and concentration of the antimicrobials. Thymus sibthorpii was determined as the strongest antimicrobial, with 0.091 mg/mL minimum inhibitory concentration (MIC) and a 14-33 mm diameter inhibition zone at 5% (v/v) concentration. All tested EOs indicated almost 95% inhibition of biofilm formation at their half MIC, while gentamicin sulfate did not show sufficient anti-biofilm activity. None of the methicillin-resistant strains showed resistance to the EOs compared to methicillin-sensitive strains. Thymus sibthorpii and Origanum vulgare could be potential alternatives as antimicrobial agents to overcome the problem of microbial resistance. The tested EOs might be incorporated into antimicrobial products as safe and potent antimicrobial and anti-biofilm agents.

Encapsulation of Cymbopogon khasiana × Cymbopogon pendulus Essential Oil (CKP-25) in Chitosan Nanoemulsion as a Green and Novel Strategy for Mitigation of Fungal Association and Aflatoxin B1 Contamination in Food System

The present study deals with the encapsulation of Cymbopogon khasiana × Cymbopogon pendulus essential oil (CKP-25-EO) into a chitosan nanoemulsion and efficacy assessment for inhibition of fungal inhabitation and aflatoxin B₁ (AFB₁) contamination in Syzygium cumini seeds with emphasis on cellular and molecular mechanism of action. DLS, AFM, SEM, FTIR, and XRD analyses revealed the encapsulation of CKP-25-EO in chitosan with controlled delivery. The CKP-25-Ne displayed enhanced antifungal (0.08 µL/mL), antiaflatoxigenic (0.07 µL/mL), and antioxidant activities (IC_{50 DPPH} = 6.94 µL/mL, IC_{50 ABTS} = 5.40 µL/mL) in comparison to the free EO. Impediment in cellular ergosterol, methylglyoxal biosynthesis, and in silico molecular modeling of CKP-25-Ne validated the cellular and molecular mechanism of antifungal and antiaflatoxigenic activity. The CKP-25-Ne showed in situ efficacy for inhibition of lipid peroxidation and AFB₁ secretion in stored S. cumini seeds without altering the sensory profile. Moreover, the higher mammalian safety profile strengthens the application of CKP-25-Ne as a safe green nano-preservative against fungal association, and hazardous AFB₁ contamination in food, agriculture, and pharmaceutical industries.

Efficacy and Mechanisms of Action of Essential Oils' Vapours against Blue Mould on Apples Caused by Penicillium expansum

Biofumigation with slow-release diffusers of essential oils (EOs) of basil, oregano, savoury, thyme, lemon, and fennel was assessed for the control of blue mould of apples, caused by Penicillium expansum. In vitro, the ability of the six EOs to inhibit the mycelial growth was evaluated at concentrations of 1.0, 0.5, and 0.1%. EOs of thyme, savoury, and oregano, at all three concentrations, and basil, at 1.0 and 0.5%, were effective in inhibiting the mycelial growth of P. expansum. In vivo, disease incidence and severity were evaluated on 'Opal' apples artificially inoculated with the pathogen and treated at concentrations of 1.0% and 0.5% of EOs. The highest efficacy in reducing blue mould was observed with EOs of lemon and oregano at 1.0% after 60 days of storage at 1 ± 1 °C (incidence of rot, 3 and 1%, respectively) and after a further 14 days of shelf-life at 15 ± 1 °C (15 and 17%). Firmness, titratable acidity, and total soluble solids were evaluated at harvest, after cold storage, and after shelf-life. Throughout the storage period, no evident phytotoxic effects were observed. The EOs used were characterised through GC-MS to analyse their compositions. Moreover, the volatile organic compounds (VOCs) present in the cabinets were characterised during storage using the SPME-GC-MS technique. The antifungal effects of EOs were confirmed both in vitro and in vivo and the possible mechanisms of action were hypothesised. High concentrations of antimicrobial and antioxidant compounds in the EOs explain the efficacy of biofumigation in postharvest disease control. These findings provide new insights for the development of sustainable strategies for the management of postharvest diseases and the reduction of fruit losses during storage.