Incorporation Of Essential Oils Research Articles

Characterization of Aloe Vera Gel-Based Edible Coating with Orange Peel Essential Oil and Its Preservation Effects on Button Mushroom (Agaricus bisporus)

In the present study, the effects of orange peel essential oils (EOs) on the physiochemical, rheological, particle size and zeta potential distribution of the developed aloe vera gel-based edible coating were investigated. We also investigated the effects of prepared aloe vera gel-based edible coating (with or without incorporation of orange peel essential oil) on the postharvest shelf life and characteristics such as physiological loss of weight (PLW), color, respiration rate, firmness, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, and antimicrobial activity of button mushroom (Agaricus bisporus) at 4 °C during 16 days of storage. The results revealed that the 50% concentration of aloe vera gel-based edible coating without addition of essential oil had significantly superior properties with higher stability zeta potential (− 9.7 mV) as compared to other concentrations of aloe vera gel-based formulation. It also showed the highest potential to maintain the postharvest quality attributes of mushrooms throughout storage. The maximum concentration of orange peel essential oil (1500 µL/L) incorporated in the 50% aloe vera gel (F3)-based treatment significantly improved the postharvest quality attributes of mushrooms as compared to coating prepared with incorporation of 500 µL/L and 1000 µL/L concentration of EOs (orange peel essential oils) and helped extend the shelf life of mushrooms up to 4 days as compared to the control (50% AV (aloe vera gel) only). Further research should be performed to develop water and gas barrier composite edible coatings to further extend mushroom shelf life.

Physical Properties, Antioxidant and Antimicrobial Activity of Chitosan Edible Films Containing Essential oils

Background: Herbs and spices, having antimicrobial effect, can be incorporated into edible films to extend product shelf life and to reduce the risk of microbial growth on food. Chitosan edible films have shown great promise for their application in food preservation and also are promising systems to be used as essential oils (EOs) carriers. This study aims to investigate the effect of EOs incorporation on the physical, antioxidant, and antimicrobial activities of chitosan films.
 Methods: Chitosan active films incorporated with cinnamon, clove, laurel, basil, and lemongrass EOs were investigated for physical parameters of color, thickness, opacity, moisture content, and water solubility in order to study the impact of the incorporation of EOs into the chitosan matrix. The antioxidant property of films was determined based on the method of DPPH to analyze and evaluate the quality of tested films. Furthermore, antibacterial activity was carried by agar diffusion method on food spoilage bacteria of Gram-positive Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, and Gram-negative Escherichia coli (E.coli), Pseudomonas aeruginosa, and klebsiella pneumonia.
 Results: In general, all chitosan EOs films presented yellowish coloration, slight thicknesses, good transparency in visible light, and high wettability. Compared to other tested films, chitosan film incorporated with clove EO had the highest total phenolic content of 0.303 mg/g Gallic acid equivalent with the highest antioxidant capacity of 89.93% value. All the films exhibited antibacterial activity against the studied food spoilage bacteria except of the chitosan films incorporated with Basil and Lemongrass EOs showed no inhibitory activity against E.coli. A significant antimicrobial bacterial inhibition zone of (20 mm) was assigned for clove chitosan film against Bacillus cereus and Staphylococcus aureus, Lemongrass chitosan film against Pseudomonas aeruginosa, and klebsiella pneumonia, and Basil chitosan films against Pseudomonas aeruginosa.
 Conclusion: Chitosan active films incorporated with the studied EOs assigned an effective antioxidant and antimicrobial activity to be used for active food packaging.

Tapioca starch-based films containing oregano, Vietnamese mint, and curry leaf essential oils for food packaging applications

Sustainable food packaging made from starch is a viable alternative to the usage of petrochemical-based plastics. The incorporation of additives, particularly essential oils, into the starch film can potentially improve the mechanical properties and enhance its functionality. The present work investigated the effects of the incorporation of different types and concentrations (0, 0.25, 0.5, 0.75, and 1%; v/v) of essential oils (EOs) from oregano, Vietnamese mint (VEO), and curry leaf on the mechanical and optical properties of starch films. Additionally, the quality attributes of strawberries wrapped using the films during storage were investigated in terms of weight loss, colour changes, and firmness. It was observed that the incorporation of EOs into the starch films improved the elongation at break, especially at higher concentrations. These films became slightly yellowish and more opaque. Besides, the changes in quality attributes of strawberries wrapped with starch/EOs films were the lowest as compared to the unwrapped strawberries and the strawberries wrapped with starch films. Starch films incorporated with 1% (v/v) VEO were the most effective films due to relatively high flexibility and low stiffness, apart from the ability to decrease the changes in quality attributes of strawberries. To conclude, the starch/EOs films have great potential for food packaging applications.

Alginate-Chitosan Membranes for the Encapsulation of Lavender Essential Oil and Development of Biomedical Applications Related to Wound Healing.

Biopolymers such as chitosan (CHT) or alginate (ALG) are among the most prominent for health-related applications due to their broad bioactivity. Their combination for the preparation of membranes is hereby proposed as an application for wound healing with the incorporation of lavender essential oil (LEO), widely known for its antioxidant and antimicrobial properties. The preparation of CHT, CHT + LEO, ALG, ALG + LEO, and CHT/ALG + LEO membranes was accomplished, and its composition was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The water absorption capacity and oil release profile of the membranes revealed higher water uptake capacity when a lower LEO release was obtained. The combined CHT/ALG + LEO film showed a water uptake percentage of 638% after 48 h and a maximum LEO release concentration of 42 mg/L. Cytotoxicity and biocompatibility of the prepared membranes were studied using a HaCaT cell line, with an assessment of cell viability regarding film leachables, DNA quantification, and DAPI-phalloidin staining. The results revealed that the indirect contact of the prepared membranes via its leachables does not compromise cell viability, and upon direct contact, cells do not adhere or proliferate on the surface of the membranes. Moreover, the CHT/ALG + LEO membrane increases cell proliferation, making it suitable for applications in wound healing.

A Comparative Study of the Properties of Gelatin (Porcine and Bovine)-Based Edible Films Loaded with Spearmint Essential Oil

Gelatin (bovine/porcine)-based edible films are considered as an excellent carrier for essential oils (EOs) to preserve food quality and extend their shelf life. Spearmint essential oil (SEO) is known for its potential antioxidant and antimicrobial effects; nevertheless, its food applications are limited due to the volatile nature of its active components. Thus, edible films loaded with essential oil can be an alternative to synthetic preservatives to improve their food applications. In the present study, the effect of SEO addition was investigated on the physicochemical properties of bovine and porcine gelatin films, and antioxidant activity was assessed. GCMS (Gas chromatography mass spectrometry) analysis revealed the presence of carvone (55%) and limonene (25.3%) as major components. The incorporation of SEO into the films decreased the opacity, moisture content, water solubility, and elongation at break of bovine and porcine gelatin films. However, with the addition of EO, the thickness and water vapor permeability of bovine and porcine-based gelatin films increased. Moreover, the addition of SEO increased the tensile strength (TS) of the porcine-based film, whereas bovine samples demonstrated a decrease in tensile strength. XRD (X-ray diffraction) findings revealed a decrease in the percentage crystallinity of both types of gelatin films. SEM (scanning electron microscope) results showed the changes in the morphology of films after the addition of SEO. Antioxidant properties significantly increased with the incorporation of EO (p < 0.05) when compared with control films. Therefore, the addition of SEO to gelatin-based edible films could be an effective approach to prepare an active food packaging material to prevent food oxidation.

Enhancement of the anti-microbial activity of Mentha spicata essential oil on storage by glycerosomes.

Mentha spicata essential oil (EO) is isolated from the aerial parts of Mentha spicata L. with pronounced antibacterial effects as food preservative in food industry. Nevertheless, its application in the clinical industry and food is significantly restricted by its poor water solubility and physicochemical instability. Glycerosomes of this EO were prepared to enhance its anti-microbial stability. The EO was encapsulated in the glycerosomes and characterized for its physical properties. The optimized EO-loaded glycerosomes displayed entrapment efficiency of 93.2 ± 7.5%, release efficiency of 75.4 ± 6.1%, the particle size of 276nm, and zeta potential of - 30.4 mV. Scanning electron microscopy (SEM) image showed spherical morphology of the glycerosomes. EO release from optimized formulation of glycerosomes best fitted with a first-order kinetic model. Compared with free EO, EO-loaded glycerosomes showed better storage stability. The results indicated that the incorporation of EO in glycerosomes possessed sustained release properties and significantly enhanced antibacterial effects in storage.

Incorporation of Plants Extracts and Essential Oils into Starch‐Based Films: A Comprehensive Review

AbstractGiven the global environmental issues associated with petroleum‐based packaging materials, developing green packaging films is a promising innovative approach to packaging food products. In this regard, starch films added with plant extracts and essential oils have been explored for different packaging types of food products. The availability of starch in nature makes starch films a cheap substitute for petroleum‐based packaging material, thus reducing the impact on the environment, packaging costs, and complexity. Recent investigations emphasize identifying and isolating natural ingredients from different plants for use in starch‐based green packaging. Plant extracts and essential oils influence the mechanical and barrier properties and impart antioxidant and antimicrobial properties to the developed films. These films show promising applications in the food industry. This review provides recent insights into the effects of plant extracts and essential oils on starch‐based green packaging films' properties.

3D simulation of nano/micro cellulose delivery systems for dermic and respiratory applications: Case study of eucalyptus essential oil incorporation

The purpose of this work was to design, develop and optimize different combinations of drug delivery systems (DDS) with nanofibrillated (NFC) and microfibrillated (MFC) cellulose-based materials, as 3D networks, encapsulating eucalyptus essential oil molecules, for dermic and respiratory applications. Experimental and computational approaches were implemented for characterization, modeling studies, and structure porosity optimization. The optimized porous structures were able to retain the desired molecules, resulting in more controlled and uniform release kinetics over time. This methodology allowed for optimizing new bio-based drug delivery systems with controlled porosity, pore dimension and distribution, retention of therapeutic molecules, and uniformity of the 3D network. The results showed that different drug delivery systems with this 3D matrix released the essential oil molecules, improving its stability and prolonging the exposure time, factors that are important to develop promising drug delivery systems in biomaterials fields. Overall, cellulose-based structured biomaterials capable of transporting and releasing essential oil components are representatives of innovative materials that will be used in novel applications, in which the exposure time to the therapeutic molecules constitutes a competitive benefit. Ziel dieser Arbeit war es, verschiedene Kombinationen von Verabreichungssystemen (DDS) mit nanofibrillierten (NFC) und mikrofibrillierten (MFC) zellulosebasierten Werkstoffen als 3D-Netzwerke zu entwerfen, zu entwickeln und zu optimieren sowie die Moleküle des ätherischen Eukalyptusöls für dermische und respiratorische Anwendungen einzukapseln. Für die Charakterisierung, die Modellierung und die Optimierung der Strukturporosität wurden experimentelle und rechnerische Verfahren eingesetzt. Die optimierten porösen Strukturen waren in der Lage, die gewünschten Moleküle zurückzuhalten, was zu einer kontrollierteren und gleichmäßigeren Freisetzungskinetik im Laufe der Zeit führte. Diese Methodik ermöglichte die Optimierung neuer biobasierter Verabreichungssysteme mit kontrollierter Porosität, Porengröße und -verteilung, Rückhaltung therapeutischer Moleküle und Gleichmäßigkeit des 3D-Netzwerks. Die Ergebnisse zeigten, dass verschiedene Verabreichungssysteme mit dieser 3D-Matrix die Moleküle des ätherischen Öls freisetzten, ihre Stabilität verbesserten und die Einwirkungszeit verlängerten – Faktoren, die für die Entwicklung vielversprechender Verabreichungssysteme im Bereich der Biowerkstoffe wichtig sind. Insgesamt sind strukturierte Biowerkstoffe auf Zellulosebasis, die in der Lage sind, ätherische Ölkomponenten zu transportieren und freizusetzen, Vertreter innovativer Werkstoffe, die in neuartigen Anwendungen eingesetzt werden, bei denen die Einwirkungszeit der therapeutischen Moleküle einen Wettbewerbsvorteil darstellt.

Essential Oil and Plant Extracts as Preservatives and Natural Antioxidants Applied to Meat and Meat Products: A Review.

The meat and meat product industry has evolved according to the needs of the market. Consumers are increasingly seeking quality in food. Thus, the concern regarding the excessive use of additives such as preservatives and antioxidants has driven research towards natural, healthy and safe substitutes. Essential oils and plant extracts have been shown to be a good option for resolving this problem. They are completely natural with biological activity, which mainly includes prevention of oxidation and the proliferation of microorganisms, thus arousing the interest of the industry and consumers. This review will present studies published in the last five years regarding the potential of essential oils and plant extracts to act as preservatives and antioxidants in meat and meat products. The forms of application, innovations in the area, alternatives to the incorporation of essential oils and extracts in meat products, effects caused in food, and limitations of applications will be detailed and discussed.

Novel antimicrobial/antioxidant Eremurus luteus root gum coating containing rosemary essential oil nanoemulsions for extension of chicken meat shelf life.

Herein, the effect of incorporation of rosemary essential oil (REO) nanoemulsions with the smallest (98.14 nm) and largest (148.04 nm) droplets' sizes at different concentrations (0%, 2%, and 4% v/v) in Eremurus luteus root gum (ELRG) coating solution on microbial, chemical, and sensory qualities of chicken fillets during cold storage was investigated. The results demonstrated a significant reduction in pH and TBA value and total viable microbial count (TVC) of chicken meat samples after using an active ELRG coating compared with the uncoated sample. Moreover, the properties of active ELRG coatings were more affected by the concentration of REO nanoemulsions than the size of their droplets. More antimicrobial and antioxidant activities were observed in coated samples containing 4% (v/v) REO nanoemulsions (L-4 and S-4). The highest and lowest pHs at the end of storage belonged to uncoated (6.89) and S-4 coated (6.41) samples, respectively. Unlike the control sample (8th day), the microbial population in the active coated samples (>12th day) reached the threshold level (7 log CFU/g) later. The TBA value in the control and coated samples was 0.56 and 0.4-0.47 mg/kg after 12 days of cold storage, respectively. Increasing the REO nanoemulsion content from 2% to 4% (v/v) in the coating solution enhanced the score of sensory parameters such as odor, color, and total acceptance of the chicken meat, especially on the last day of cold storage. The obtained results suggested ELRG-REO coatings as an effective strategy to delay the chemical and microbial deterioration of chicken meat fillets.

Characterization and Antimicrobial Activity Studies of Agave Sheets with Thymol and Clove Oil for Active Packaging

ABSTRACT Antimicrobial active sheets based on agave ultimate fibers were prepared by incorporating essential oils (thymol and clove oil) at different concentrations. A complete structural, mechanical, and antimicrobial characterization of treated samples was carried out. SEM proved the presence and the deposit of additives on the surface of the sheet. FTIR spectra confirm the incorporation of essential oils into treated papers. Mechanical properties reveal a decrease in elastic modulus from 31.1 kN/m for raw sheet to 17.8 kN/m for thymol and to 26.7 kN/m for clove oil for treated sheets, and tensile strength from 28.2 N to 24.1 N for thymol and to 14.1 N for clove oil was obtained for the active sheets compared with raw sheets. While the presence of additives increased slightly the elongation at yield of treated samples from 2.3% to 2.6% for thymol and to 2.8% for clove oil. Regarding antibacterial activity, thymol and clove oil showed inhibition against strain present in food. Thymol had the higher inhibition against S. aureus (4.08 cm), and clove oil had the best inhibition against E. coli. (4.13 cm). The obtained results proved that active agave sheets are able to be used as antimicrobial packaging.

Physicochemical and Antimicrobial Characterization of Chitosan and Native Glutinous Rice Starch-Based Composite Edible Films: Influence of Different Essential Oils Incorporation

Biopolymer-based edible packaging is an effective way of preserving food while protecting the environment. This study developed an edible composite film using chitosan and native glutinous rice starch (NGRS) and incorporated essential oils (EOs) such as garlic, galangal, turmeric, and kaffir lime at fixed concentrations (0.312 mg/mL) to test its physicochemical and antimicrobial properties. The EO-added films were found to significantly improve the overall color characteristics (lightness, redness, and yellowness) as compared to the control film. The control films had higher opacity, while the EO-added films had slightly reduced levels of opacity and produced clearer films. The tensile strength and elongation at break values of the films varied among the samples. The control samples had the highest tensile strength, followed by the turmeric EO-added samples. However, the highest elongation at break value was found in the galangal and garlic EO-added films. The Young's modulus results showed that garlic EO and kaffir lime EO had the lowest stiffness values. The total moisture content and water vapor permeability were very low in the garlic EO-added films. Despite the differences in EOs, the Fourier-transform infrared spectroscopy (FTIR) patterns of the tested films were similar among each other. Microstructural observation of the surface and cross-section of the tested edible film exhibited smooth and fissureless patterns, especially in the EO-added films, particularly in the galangal and kaffir lime EO-added films. The antimicrobial activity of the EO-added films was highly efficient against various gram-positive and gram-negative pathogens. Among the EO-added films, the garlic and galangal EO-added films exhibited superior inhibitory activity against Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Pseudomonas fluorescence, and turmeric and kaffir lime EO-added films showed potential antimicrobial activity against Lactobacillus plantarum and L. monocytogenes. Overall, this study concludes that the addition of EOs significantly improved the physicochemical and antimicrobial properties of the CH-NGRS-based edible films, making them highly suitable for food applications.

Fabrication of nano-encapsulated angelica (Heracleum persicum) essential oil for enriching dairy dessert: Physicochemical, rheological and sensorial properties.

In this study, the nanoemulsions containing angelica essential oil (AEO) was used as a novel nano-carrier for enrichment of dairy dessert. Firstly, oil-in-water nanoemulsions were prepared by different levels of GE (1%, 5%, 10%, and 15%) as the dispersed phase, Tween 80 as surfactant with a constant surfactant to essential oil ratio (1:1), and distillated water as a continuous phase. Droplet size, free radical scavenging capacity, antimicrobial activity against gram-positive (Staphylococcus aureus (25923 ATCC)) and gram-negative (Escherichia coli H7 O157 (700728 ATCC)) were evaluated for produced nanoemulsions. The mean droplet size of nanoemulsion increased from 75 to 95nm and antioxidant capacity also enhanced from 15.4% to 30.2% by increasing AEO level from 1% to 15%. Antimicrobial analysis by disk diffusion methods for nanoemulsions containing different levels of AEO cleared that nanoemulsions with high levels of AEO showed the stronger antimicrobial activity against both used bacteria and especially more activity against Staphylococcus aureus. The results of the total count and yeast and mould count show that the nanoemulsions with different levels of AEO have been effective on the number of microorganisms, particularly during storage. The incorporation of pure essential oil and nanoemulsions with different levels of AEO did not affect significantly the pH of different dessert samples however, they affected the dry matter and free radical scavenging capacity. Adding of nanoemulsions with different levels of AEO to the desserts had a considerable effect on the rheological properties including apparent viscosity, G', G", Tan δ and complex viscosity and all samples showed shear-thining behaviour. Results from organoleptic characteristics (taste, odour colour, mouthfeel and total acceptance) showed that enriched samples by nanoemulsions, particularly with higher level of AEO had higher sensorial scores. In general, samples containing free AEO (not encapsulated) had the lower scores in all organoleptic characteristics.

Characterization of Solution Blow Spun Poly(Lactic) Acid Based Nanofibers Containing Sucuk Spice Mix Essential Oils

In this study, essential oil (EO) from sucuk spice mix was incorporated into poly(lactic) acid (PLA) and nanofibers were produced via solution blow spinning (SBS). EO incorporation was performed at 0, 5, 10, 15, 20, 25, and 30% (v/w) of PLA. Mechanical, barrier, microstructural, topographical, contact angle, chemical, thermal, antioxidant, and antibacterial properties against E. coli and S. aureus were characterized. Nanofibers were not soluble in water due to the hydrophobic nature of PLA. Microstructural images revealed that beadles and uniform nanofibers can be produced with SBS, and EO addition decreased the average fiber diameter. The surface topography of nanofibers was improved by increasing EO concentration. Melting and glass transition temperatures decreased and the thermal stability of nanofibers increased with EO addition. Nanofibers containing EO at 30% had the highest antioxidant capacity (40.02%). Nanofibers containing 20, 25, and 30% of EO had greater growth inhibition against Staphylococcus aureus and Escherichia coli. As a result, PLA-based nanofibers containing sucuk spice mix EO can be produced with SBS, and nanofibers containing 20, 25, and 30% EO could be a promising system not only in drug delivery systems but also in food packaging.

Development of zinc oxide nanoparticles as safe coating for the shelf life extension of grapes (Vitisvinifera L., Red Globe) fruits

The effects of zinc oxide nanoparticles coating (NZO) developed from chitosan (CH) with incorporation of bergamot essential oil (BO) were investigated to extend the shelf life of grapes (Vitisvinifera L., Red Globe). Treated and untreated grapes were determined for some postharvest and phytochemical properties such as decay incidence, firmness, polyphenol oxidase enzyme activity (PPO), proximate analysis, and sensory evaluations. Besides, that microbial growth against S. typhimurium bacteria was also evaluated during 16 days of storage period of grapes at 25 °C. Descriptions of coating treatments were the following; control “COL” (distilled water/glycerol (1%)/acetic acid (0.5%)); chitosan “CH” with priority 85% (1%), distilled water/glycerol (1%)/acetic acid (0.5%); chitosan/nano zinc oxide (1%), partial size of (15 nm) “CH-NZO;” chitosan/nano zinc oxide/bergamot oil (1%) “CH-NZO-BO.” The control treated berries started to rot after 7 days; the noted highest corruption on 16th day s of storage (32.51). While CH berries coated became rotten after 9 days, those coated with CH–NZO and CH–NZO–BO achieved the lowest decay incidence percentage with no remarkable differences after 16 days (10.11% and 9.13%), respectively. The loss of firmness value was more seriously considered for the COL berries 3.84 N after the 16th day. On the other hand, the highest firmness value was for CH–NZO–BO which recorded 8.27 N. In the same trend, CH and CH–NZO achieved similar values after 16 days (6.31 N and 6.98 N), respectively. The lowest PPO activity was observed for COL berries at 0.31 Unit/Minute after 16 days of storage. Though, the highest activity was recorded by CH–NZO–BO treatment at 0.99 Unit/Minute. The content of proteins was between 2.32 and 3.04%, fats between 0.30 and 0.43%, and total carbohydrates between 78.47 and 78.65% on the 16th day of storage. The highest reduction in the numbers of microbial growth 2.78 Log CFU/Berry occurred by coating with CH–NZO–BO at the end of the storage period, while no inhibition was detected with COL and CH treatments which recorded 4.99 and 4.69 Log CFU/Berry, respectively. The visual aspect in COL samples showed a serious reduction of 1.10 with high rates of dehydration and browning, while CH-NZO–BO samples showed the highest rate of 4.33. CH–NZO–BO samples also showed a relatively high rate of firmness of 4.11, crunchiness of 3.92, and sourness of 3.53. CH–NZO recorded the highest rates for juiciness 4.15 and sweetness 3.51. Though, the CH–NZO–BO coating can be recommended for food industry.

Development of Active Films with Collagen Fiber and Polyvinyl Alcohol Mixture and Incorporation of Oregano and Rosemary Essential Oils in Their Matrix

Development of Active Films with Collagen Fiber and Polyvinyl Alcohol Mixture and Incorporation of Oregano and Rosemary Essential Oils in Their Matrix

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.

Incorporation of nisin and oregano essential oil in cow’s milk to improve the quality of fresh cheese

Firstly, this study aimed to determine the effect of adding nisin (0, 250 and 500 IU mL-1) and oregano essential oil (OEO) (0, 0.025% and 0.05%), alone or in combination, on Staphylococcus aureus load in cow’s milk. Next, it was evaluated the sensory, physicochemical and microbiological quality of fresh cheese (FC) manufactured with milk added of nisin + OEO (C1) or nisin alone (C2) compared to a control cheese (C0, milk without the addition of nisin or OEO). Results showed that adding nisin effectively reduced the S. aureus count in milk in a similar manner to adding way the combination of nisin + OEO compared to the control. FC quality evaluation results revealed that C1 and C2 did not alter the physicochemical quality of FC (pH, fat and total solids content) during storage (0-8 days) compared to the control. Furthermore, C1 and C2 reduced in a similar manner aerobic mesophilic bacteria and Enterobacteriaceae count in FC compared to the control during storage. Sensory evaluation showed that consumers did not value FC added of nisin + OEO (C1) due to its intense aroma of oregano, rating it with the lowest global quality.

Incorporation of Saqez essential oil into polyvinyl alcohol/chitosan bilayer hydrogel as a potent wound dressing material

Nowadays, many studies are conducted on multilayer hydrogels for wound dressing. On the other hand, considering the emergence of bacterial resistance to common antibiotics, studies on the use of natural essential oils and their derivatives that have antibacterial and antioxidant activity can be useful. Herein, a novel bilayer hydrogel developed from polyvinyl alcohol and chitosan with the incorporation of Saqez essential oil (SEO) was synthesized. The results showed a gel-type structure with specific compression and flexibility, while the microscopic images confirmed the formation of a bilayer hydrogel. Further, the data showed that increasing the concentration of SEO reduces the swelling and water vapor permeability and increases the water retention and hydrophobicity of the hydrogel surface. The effects of the combination of SEO in the bilayer hydrogel led to a strong antioxidant property and increased antimicrobial activity. Also, the in vitro results demonstrated that the bilayer hydrogels are biocompatible, non-toxic, and blood compatible. Finally, the results of the in vivo tests showed that these bilayer hydrogels had good homeostatic efficiency. Overall, the obtained results indicate that these bilayer hydrogels are promising candidates for wound dressing.

Antiadhesion effect of the chitosan-based film incorporated with essential oils against foodborne bacteria

In the food sector, bacterial adhesion on surfaces followed by biofilm development is responsible for food contamination and spoilage, and foodborne illness , leading to considerable economic losses. Therefore, this present study aimed to elaborate a biodegradable material that inhibits bacterial adhesion and thus biofilm formation. For this purpose, chitosan-based films (CH-films) containing four different essential oils (EOs) were elaborated. The impact of these EOs on the physicochemical properties as well as the antiadhesion activity of the CH-films was evaluated. The contact angle results showed that the addition of EOs has modified significantly the physicochemical properties of the CH-film. The electron donor (γ - ) and Lifshitz-Van der Waals component (γ LW ) values increased, whereas the qualitative hydrophobicity ( θ w) and electron acceptor (γ + ) values decreased. The analysis of bacterial adhesion using environmental scanning electron microscopy (ESEM) revealed that the CH-film containing C. zeylanicum EO exhibits the strongest antiadhesion activity against E. coli , E. hirae , and S. aureus compared to the other CH-films, with coverage rate values equal to 5.16 ± 1.13%, 2.8 ± 0.38%, and 1.52 ± 0.53%, respectively. Moreover, ESEM analysis showed that the antiadhesion effect of C. zeylanicum EO on P. aeruginosa strain was accompanied by a rupture of bacterial cells. From these findings, the CH-films incorporated with EOs could potentially be applied in the food industry to prevent microbial adhesion to surfaces and eventual biofilm formation. • The elaboration of a biodegradable film with antiadhesion activity using chitosan and essential oils. • The chemical constituents of pelargonium, thyme, cinnamon, and clove essential oils were identified. • The physicochemical properties of the chitosan-based film were affected by the incorporation of essential oils. • The chitosan-based film containing cinnamon essential oil showed strong antiadhesion activity against the tested strains. • The cell structure of P. aeruginosa was destabilized after contact with the film containing cinnamon essential oil.