Antioxidant and antibacterial effects of Lavandula and Mentha essential oils in minced beef inoculated with E. coli O157:H7 and S. aureus during storage at abuse refrigeration temperature

Rhamnolipids stabilized essential oils microemulsion for antimicrobial and fruit preservation

Essential oils, well-known for their antifungal properties, are widely utilized to combat fruit decay. However, their application faces big challenges due to their high volatility and hydrophobic traits, which leads to strong odor, short effective time and poor dispersivity. This study aimed to address these challenges by formulating microemulsions consisting of essential oils and rhamnolipids. The optimized microemulsion, featuring a small particle size of 6.8 nm, exhibited higher stability and lower volatility than conventional emulsion. Notably, the prepared microemulsions demonstrated remarkable antimicrobial efficacy against E. coli, S. aureus, C. albicans, S. cerevisiae, and A. niger. The application of these microemulsions proved to be highly effective in preventing blueberry decay while preserving fruit's quality, particularly by minimizing the loss of essential nutrients such as anthocyanins. Consequently, essential oil microemulsions emerge as a highly effective postharvest preservative for fruits, offering a promising solution to extend their shelf life and enhance overall quality.

Development of stability, antioxidant, and antimicrobial properties of biopolymeric chitosan modified starch nanocapsules containing essential oil

Lemon essential oil (LEOs) is used as a bioactive compound with unique health properties as a medicine or dietary supplement. Nevertheless, essential oils are chemical compounds sensitive to light, oxidation, and thermal processes. Therefore, encapsulation technique can be a good way to protect them from degradation and evaporation. In current study, biopolymeric nanocapsules containing lemon essential oils (LEOs) were prepared by the emulsion method. The nanocapsules were characterized by their particle size and Encapsulation efficiency (%) ranged from 339.3 to 553.3 nm and 68.09% to 85.43%, respectively. Long-term storage (30 days) under different temperatures (4 °C, 25 °C, and 40 °C) conditions showed that nanocapsules stored at 4 °C were more stable than samples stored at higher temperatures. DPPH and ABTS free radical scavenging activity were measured to evaluate the values of antioxidant activity of LEOs and nanocapsules. The free LEO and nanocapsules were investigated for its antibacterial activity against common Gram-positive and Gram-negative pathogenic microorganisms (Staphylococcus aureus and Escherichia coli) using disk diffusion followed by the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our results indicated that the encapsulated LEOs had a significant antioxidant and antibacterial activities, as compared to the free LEO. The LEOs nanocapsules in CS and Hicap can be suggested as an important natural alternative with suitable stability, antioxidant, and antibacterial properties to overcome the challenges associated with the direct application of these bioactive compounds in food.

Evaluation of the Antimicrobial Activity of Geraniol and Selected Geraniol Transformation Products against Gram-Positive Bacteria

Both geraniol and the products of its transformation, thanks to their beneficial properties, find a variety of applications in cosmetics. Due to their antioxidant and moisturizing properties, these compounds can be added to skin care products such as face creams, lotions, oils, and masks. In addition, these compounds show some antibacterial and antifungal properties, making them suitable for application in skin care products to help fight against bacteria or fungi. This study determined the antimicrobial activity of geraniol and the compounds which were formed during its transformation in relation to selected Gram-positive bacteria, and the preliminary assessment was made whether these compounds can act as ingredients of preparations with potential antimicrobial activity in the treatment of various human diseases (for example diseases of the skin, digestive system, or urinary tract). In addition, this work presents studies on the microbiological purity of cream samples obtained with different contents of geraniol and its transformation products (contents of the tested compounds: 0.5%, 1.5%, 2.5%, 4%, 8%, and 12%). Antibacterial activity tests were performed using the disc diffusion method against Gram-positive cocci, including the reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212, and against the clinical strains Staphylococcus aureus MRSA, Staphylococcus epidermidis, Enterococcus faecalis VRE VanB, Enterococcus faecium VRE VanA, and Enterococcus faecium VRE VanB. The most active ingredient against bacteria of the Staphylococcus genus was citral, followed by linalool and then geraniol. During our tests, in the case of bacteria of the Enterococcus genus, citral also showed the highest activity, but linalool, ocimenes, and geraniol showed a slightly lower activity. Moreover, this study examined the microbiological purity of cream samples obtained with various contents of geraniol and its transformation products. In the tests of the microbiological purity of cream samples, no growth of aerobic bacteria and fungi was found, which proves the lack of microbiological contamination of the obtained cosmetic preparations. On this basis, it was assessed that these compounds have preservative properties in the prepared creams. The addition of the analyzed compounds also had influence on the durability of the creams and had no effect on the change in their consistency, did not negatively affect the separation of phases during storage, and even had a positive effect on organoleptic sensations by enriching the smell of the tested samples.

Nanoencapsulated Thymus daenensis and Mentha piperita essential oil for bacterial and biofilm eradication using microfluidic technology

The use of essential oil (EO) nanoemulsions is expanding to meet customer demand for all-natural antibacterial agents. Thymus daenensis (T) and Mentha piperita (M) EOs were employed to make nanoemulsions (TEO and MEO NE), using Tween 80/Span 80 as surfactant/cosurfactant and a high-speed homogenizer. The TEO and MEO NEs were then characterized in terms of particle size (121, 113 nm), surface charge (-11.2 and -12.6 mV), morphology, and stability over time. Then, the antibacterial activity of EOs and their nanoformulations against Escherichia coli (E. coli) were evaluated based on various residence times, and concentrations on a microfluidic chip. The release of cytoplasmic constituents was used to compare the antibacterial activity of bulk EOs and nanoformulations. After completing MIC, MBC, and time-killing assays, the inhibitory effect of nanoformulations on E. coli biofilm formation was examined. Remarkable intensification was observed by employing a microfluidic chip owing to high-contact surface area provision between nanoemulsions and bacteria. Once compared to the conventional method for 3 h operation, the bacterial activity was nearly completely inhibited in a 24-min residence time using nanoemulsions. After 6 min of treatment, the cell membrane began to rupture, indicating that nanoemulsions could improve the antibacterial activity of bulk essential oils.

In vitro antimicrobial activity of extracts and essential oils of Cinnamomum, Salvia, and Mentha spp. against foodborne pathogens: A meta-analysis study

Essential oils (EOs) are a class of natural products that exhibit potent antimicrobial properties against a broad spectrum of bacteria. Inhibition diameters (IDs) and minimum inhibitory concentrations (MICs) are the typical measures of antimicrobial activity for extracts and EOs obtained from Cinnamomum, Salvia, and Mentha species. This study used a meta-analytical regression analysis to investigate the correlation between ID and MIC measurements and the variability in antimicrobial susceptibility tests. By utilizing pooled ID models, this study revealed significant differences in foodborne pathogens' susceptibility to extracts, which were dependent on both the plant species and the methodology employed (p < .05). Cassia showed the highest efficacy against Salmonella spp., exhibiting a pooled ID of 26.24 mm, while cinnamon demonstrated the highest efficacy against Bacillus cereus, with a pooled ID of 23.35 mm. Mint extract showed the greatest efficacy against Escherichia coli and Staphylococcus aureus. Interestingly, cinnamon extract demonstrated the lowest effect against Shiga toxin-producing E. coli, with a pooled ID of only 8.07 mm, whereas its EOs were the most effective against this bacterial strain. The study found that plant species influenced the MIC, while the methodology did not affect MIC measurements (p > .05). An inverse correlation between ID and MIC measurements was identified (p < .0001). These findings suggest that extracts and EOs obtained from Cinnamomum, Salvia, and Mentha spp. have the potential to inhibit bacterial growth. The study highlights the importance of considering various factors that may influence ID and MIC measurements when assessing the effectiveness of antimicrobial agents.

Use of Algerian Type Ras El-Hanout Spices Mixture with Marination to Increase the Sensorial Quality, Shelf Life, and Safety of Whole Rabbit Carcasses under Low-O2 Modified Atmosphere Packaging

This study aimed to evaluate the effect of combined treatments with Ras El-Hanout spices mixture and marinade solution containing extra virgin olive oil, onion, garlic, and concentrated lemon juice on sensorial quality, shelf life, and safety of whole rabbit carcasses under low-O2 modified atmosphere packaging (MAP). The values of pH, water holding capacity, shear force, thiobarbituric acid reactive substances, total volatile basic nitrogen, color (CIE L*a*b*), sensorial tests, and spoilage microorganisms were determined in rabbit meat at 0, 5, 10, 15, and 20 days during a retail display at 7 ± 1 °C. The results indicated that the marination process using the Ras El-Hanout blend of spices improved the water-holding capacity of meat maintaining optimum pH values. This combined treatment delayed the growth of major spoilage microorganisms, lipid oxidation, protein degradation, and undesirable color changes compared to unmarinated samples from the fifth to the twentieth day of retail exposure. The shelf life of rabbit carcasses under low-O2 MAP could be extended to 20 days of retail display, while rabbit carcasses under aerobic display presented a shorter shelf life of 5 to 10 days. Instrumental and sensorial tests showed that low-O2 MAP enhanced the tenderness of whole rabbit carcasses, with those marinated with Ras El-Hanout being the most positively perceived by the panelists. Marination also inhibited the pathogen Campylobacter jejuni, thus increasing the microbiological safety of the packaged product. The overall results indicated that low-O2 MAP combined with the Ras El-Hanout spice blend and marinade solution may represent a promising strategy for retail establishments to improve the quality, shelf life, and safety of rabbit carcasses.

Nano-emulsification essential oil of Monarda didyma L. to improve its preservation effect on postharvest blueberry

The reduction in blueberry harvest due to pathogen infection was reported to reach 80%. Essential oil (EO) can provide a new way to preserve blueberry. Here, in search for plants volatiles with preservation ability, a novel device was designed for the screening of aromatic plants led to the discovery of hit plant Monarda didyma L. Consequently, antifungi activity of M. didyma EO (MEO) and its nano-emulsion (MNE) were tested. 2 species of pathogenic fungi were isolated from blueberries, namely Alternaria sp. and Colletotrichum sp. were used as the target strains. In the in vitro activity test, the pathogenic were completely inhibited when the EO was 4 µL or 1.0 µL/mL. Compared with EO, MNE exhibited superior antimicrobial activity. Moreover, MNE can cause serious morphological changes and result in a decrease in the rot and weightlessness rate of blueberry. Hence, NME represents a promising agent for the preservation of postharvest blueberry.

A review of the bioactive components and pharmacological properties of Lavandula species

Lavandula species is a flowering plant that is common in Europe and across the Mediterranean. Lavender has many health benefits for humans. In addition to its use in herbal medicine, it is widely used in the fields of cosmetics, perfumes, foods, and aromatherapy. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical ingredients, the pharmacologic effects of the ingredients, and the mechanism of action of the Lavandula species identified. These materials were reviewed in order to have access to important updates about the Lavandula species. Lavender as referred to in English contains essential oils, anthocyanins, phytosterols, sugars, minerals, coumaric acid, glycolic acid, valeric acid, ursolic acid, herniarins, coumarins, and tannins. It has been used to treat colic and chest ailments, worrisome headaches, and biliousness, and in cleaning wounds. It has antifungal, antibacterial, neurologic, antimicrobial, anti-parasitic, anti-diabetic, and analgesic effects among others. Lavandula species has prospects for various biological applications, especially with its dermatological application. Advances in drug development would enable characterization of various bioactive constituents; thus, its development and application can have a more positive impact on humanity. Here, we highlighted updated information on the history, distribution, traditional uses, phytochemical components, pharmacology, and various biological activities of Lavandula species.

Menthone Exerts its Antimicrobial Activity Against Methicillin Resistant Staphylococcus aureus by Affecting Cell Membrane Properties and Lipid Profile

Objective

The characteristic constituents of essential oils from aromatic plants have been widely applied as antimicrobial agents in the last decades. However, their mechanisms of action remain obscure, especially from the metabolic perspective. The aim of the study was to explore the antimicrobial effect and mechanism of menthone, a main component of peppermint oil, against methicillin resistant Staphylococcus aureus (MRSA).

Methods

An integrated approach including the microbiology and the high-coverage lipidomics was applied. The changes of membrane properties were studies by the fluorescence and electron microscopical observations. The lipid profile was analyzed by ultra-high performance liquid chromatography coupled with quadruple Exactive mass spectrometry (UHPLC-QE-MS). The lipid-related key targets which were associated with the inhibitory effect of menthone against MRSA, were studied by network analysis and molecular docking.

Results

Menthone exhibited antibacterial activities against MRSA, with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 3,540 and 7,080 μg/mL, respectively. The membrane potential and membrane integrity upon menthone treatment were observed to change strikingly. Further, lipids fingerprinting identified 136 significantly differential lipid species in MRSA cells exposed to menthone at subinhibitory level of 0.1× MIC. These metabolites span 30 important lipid classes belonging to glycerophospholipids, glycolipids, and sphingolipids. Lastly, the correlations of these altered lipids, as well as the potential metabolic pathways and targets associated with menthone treatment were deciphered preliminarily.

Conclusion

Menthone had potent antibacterial effect on MRSA, and the mechanism of action involved the alteration of membrane structural components and corresponding properties. The interactions of identified key lipid species and their biological functions need to be further determined and verified, for the development of novel antimicrobial strategies against MRSA.

Investigation of the effect of lavender (Lavandula angustifolia Mill.) essential oil on microbiological, physicochemical, and sensorial properties of meatballs during shelf-life, and its inhibitory effect on Escherichia coli O157:H7

The present work aimed at investigating the effect of lavender (Lavandula angustifolia Mill.) essential oil on the microbiological, physicochemical, and sensorial properties of meatballs, and elucidating its antimicrobial effect on the meatballs contaminated with Escherichia coli O157:H7. The essential oil as determined via gas chromatography mass spectrometry (GC-MS) contained two major components, linalool and linalyl acetate, at 37.023 and 28.651%, respectively. The antioxidant activity test which was performed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity test, revealed that the essential oil had moderate capacity. The antibacterial activity of the essential oil was investigated against E. coli O157:H7, and the minimum inhibition concentration (MIC) was determined to be 6.4 μL/mL. Six different test groups were formed based on the concentrations of E. coli O157:H7 (0 and 108 CFU/mL) and essential oil (0, 6.4, and 12.8 μL/mL). Although essential oil had inhibitory effect against TAMB, coliforms, yeasts and moulds, Staphylococcus aureus, E. coli, and especially E. coli O157:H7 in the microbiological analyses, no effect was observed on the physicochemical properties of the meatballs. Approximately, 3 log decrease was observed in the E. coli O157:H7 levels when essential oil was added at a concentration of two-fold MIC value. It was observed that the addition of essential oil to meatballs did not increase the lipid oxidation level as much as the control group. Meatballs that contained essential oil at MIC value achieved the highest general acceptability scores at the end of their storage periods.

Preliminary Microbiological Tests of S-Carvone and Geraniol and Selected Derivatives of These Compounds That May Be Formed in the Processes of Isomerization and Oxidation

This work presents a literature review on the biological activity of S-carvone, geraniol and derivatives of these compounds, which are formed in the process of isomerization (during the process of geraniol isomerization, oxidation products of this compound are also obtained). Moreover, this work presents preliminary microbiological tests of creams with the addition of these biologically active compounds: S-carvone, geraniol, carvacrol (an S-carvone isomerization product), nerol (a geraniol isomerization product), linalool (a geraniol isomerization product) and citral (a geraniol oxidation product). Because the post-reaction mixture obtained after the S-carvone isomerization has a relatively simple composition, it was also added to creams and tested without isolating pure compounds. This may be a cheaper alternative to creams prepared with the addition of pure compounds. The mixture obtained after the geraniol isomerization process has a very complex composition; therefore, only compounds with the lowest molecular weight and are easily commercially available were selected for studies. The content of the tested compounds in the creams ranged from 0.5 to 3 wet%. The following microorganisms were selected for microbiological tests: the Gram-negative bacterium Escherichia coli K12, the Gram-positive bacterium Staphylococcus epidermidis, and the fungi Candida albicans, Trichophyton rubrum, Aspergillus niger, and Penicillium chrysogenum. A content of 3% carvacrol, nerol, geraniol and citral inhibited the growth of E. coli, and attenuated the growth of C. albicans and T. rubrum. On the other hand, 3% carvacrol and citral only poorly attenuated the growth of the mould fungi P. chrysogenum and A. niger.

The Essential Oil of Tunisian Halophyte Lobularia maritima: A Natural Food Preservative Agent of Ground Beef Meat

This study was directed towards the investigation of the chemical composition and antimicrobial properties of the essential oil of Tunisian halophyte Lobularia maritime (LmEO). The antibacterial effects against major food-borne pathogenic and food spoilage bacteria were tested using the well diffusion method, followed by the determination of the minimum inhibitory (MIC) and bactericidal (MBC) concentrations. The essential oil has shown strong antimicrobial activity against eight pathogenic strains, which was attributed mostly to predominant constituents of the essential oil: benzyl alcohol, linalool, terpien-4-ol and globulol, as well as to synergistic effects of its major and minor constituents. Considering strong antimicrobial effects of the tested essential oil, it was further tested as a natural alternative to food preservatives, using minced beef meat as a model system. Minced beef meat was spiked with 0.019, 0.038, and 0.076% of the essential oil and stored during 14 days at 4 °C, monitoring its microbiological, physicochemical, and sensory properties. Chemical analyses revealed that meat treated with 0.076% of LmEO at underwent a significant decrease (p < 0.05) in primary and secondary lipid oxidation and reduced metmyoglobin accumulation compared with control samples. Furthermore, microflora proliferation in the meat model system spiked with 0.076% of LmEO was significantly (p < 0.05) reduced in comparison to control. In addition, two multivariate exploratory techniques, namely principal component analysis (PCA) and hierarchical analysis (HCA), were applied to the obtained data sets to describe the relationship between the main characteristics of the meat samples with and without essential oil addition. The chemometric approach highlighted the relationships between meat quality parameters. Overall, results indicated that the essential oil of Lobularia maritima deserves to be considered as a natural preservative in the meat industry.

Application of Ag@SiO2 nanoparticles within PVA to reduce growth of E. coli and S. aureus in beef patties

To overcome defects of polyvinyl alcohol (PVA) and expand its applications in food preservation, PVA/Ag@SiO₂ nanocomposite films were prepared using the solution intercalation film-casting method. Transmission electron microscopy, X-ray diffraction, and UV-visible absorption spectra were applied to confirm the synthesis of the nanoparticles (NPs). Effects of Ag@SiO₂ NPs on physicochemical characteristics of films like viscosity, swelling ratio, tensile strength, elongation at break, as well as antibacterial activity were also evaluated. Results indicate that Ag@SiO₂ NPs could be synthesized successfully, and the increasing concentration of Ag@SiO₂ NPs led to the decrease in viscosity and the swelling ratio of the PVA/Ag@SiO₂ NPs nanocomposite films. PVA/Ag@SiO₂ nanocomposite films exhibited increased tensile strength and strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The films had higher antibacterial activity toward E. coli compared with S. aureus. Beef patties were applied to verify the practicality of PVA/Ag@SiO₂ films. PVA/Ag@SiO₂ NPs nanocomposite films act as an active food packaging system showing great potential in retaining food safety and prolonging the shelf-life of packaged foods. PRACTICAL APPLICATION: During the storage of fresh meat, the microbial count on the meat surface increased with increasing storage time; meat proteins could be broken down by microorganisms, causing the tissue structure to be destroyed, leading to loose muscle fibers and loss of nutrient-containing juices. In this paper, by improving the PVA film, a new antibacterial membrane was prepared, which can be used for fresh meat sold in supermarkets, as a lining at the bottom of the meat or directly covering the meat. The method can significantly decrease the number of microorganisms and extend the shelf-life of fresh meat.

Exogenous Paclobutrazol Reinforces the Antioxidant and Antimicrobial Properties of Lavender (Lavandula officinalis L.) Oil through Modulating Its Composition of Oxygenated Terpenes

Plant growth regulators can affect the primary and secondary metabolites of various plant species. However, the effect of paclobutrazol (PBZ) on the composition of lavender oil, especially related to the terpenoid pathway, is still unclear in literatures. In this study, the effect of PBZ as a foliar spray (0.200, 400 and 600 ppm) on the vegetative growth, phytochemical content, and both antioxidant and antimicrobial properties of lavender oil were investigated. The results indicated that all examined PBZ treatments led to a significant (p ≤ 0.05) decrease in growth parameters compared to the untreated plants. Meanwhile, the yield of essential oil was significantly decreased by the treatment of PBZ at 200 ppm compared to the control. In contrast, applied-PBZ significantly enhanced the chlorophyll content and displayed a marked change in the composition of the essential oil. This change included an obvious and significant increase in 3-carene, eucalyptol, γ-terpinene, α-pinocarvone, caryophyllene, β-vetivenene, β-santalol, ledol, geranyl isovalerate, farnesol, caryophyllene oxide, and phytol percentage. Generally, the highest significant values were achieved by the treatment of 400 ppm compared to the other treatments. Furthermore, this treatment showed the highest free radical scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) by 13% over the control. Additionally, to determine the antimicrobial activities of the extracted oil, each treatment was examined against two strains of Gram positive bacteria (S. aureus and B. cereus), two strains of Gram negative bacteria (S. enteritidis and E. coli), and two fungal species (C. albicans and A. niger) represent the yeast modal and filamentous fungus, respectively. The findings demonstrated that all examined species were more sensitive to the oil that was extracted from lavender plants, treated with 400 ppm PBZ, compared to the other concentrations.

The Effect of Inhalation Aromatherapy on Sedation Level, Analgesic Dosage, and Bispectral Index Values during Donor Site Dressing in Patients with Burns: A Randomized Clinical Trial

OBJECTIVE

To determine the effect of inhalation aromatherapy on sedation level, analgesic dosage, and bispectral index (BIS) values during donor site dressing in patients with burns.

METHODS

This trial was conducted on 62 patients with burns requiring donor site dressing who were admitted to the Burn Center of Imam Reza Hospital, Mashhad, Iran. In the intervention group, the patients inhaled damask rose 40% and lavender 10% essential oils during donor site dressing change, whereas in the control group, the site was dressed using routine protocol. Sedatives and analgesics were prescribed until the levels of brain activity achieved light sedation. The brain activity and sedation levels were measured before and after the donor site dressings using the BIS. Data were analyzed using the analysis of covariance and the two-way analysis of variance with repeated measures.

RESULTS

All 62 patients completed the study. The required doses of ketamine (P < .001), fentanyl (P = .003), morphine (P < .001), and propofol (P < .001) were significantly lower in the intervention group. The BIS was also significantly lower in the intervention group (P < .001). Heart rate decreased significantly during the aromatherapy, as well as after analgesic and sedative consumption (P < .001).

CONCLUSIONS

The inhalation of damask rose and lavender essential oils is an effective intervention to reduce the doses of sedative and analgesic drugs administered as well as BIS during donor site dressing change in patients with burns.

Chemical Composition and Assessment of Antimicrobial Activity of Lavender Essential Oil and Some By-Products

The producers of essential oils from the Republic of Moldova care about the quality of their products and at the same time, try to capitalize on the waste from processing. The purpose of the present study was to analyze the chemical composition of lavender (Lavanda angustifolia L.) essential oil and some by-products derived from its production (residual water, residual herbs), as well as to assess their “in vitro” antimicrobial activity. The gas chromatography-mass spectrometry analysis of essential oils produced by seven industrial manufacturers led to the identification of 41 constituents that meant 96.80–99.79% of the total. The main constituents are monoterpenes (84.08–92.55%), followed by sesquiterpenes (3.30–13.45%), and some aliphatic compounds (1.42–3.90%). The high-performance liquid chromatography analysis allowed the quantification of known triterpenes, ursolic, and oleanolic acids, in freshly dried lavender plants and in the residual by-products after hydrodistillation of the essential oil. The lavender essential oil showed good antibacterial activity against Bacillus subtilis, Pseudomonas fluorescens, Xanthomonas campestris, Erwinia carotovora at 300 μg/mL concentration, and Erwinia amylovora, Candida utilis at 150 μg/mL concentration, respectively. Lavender plant material but also the residual water and ethanolic extracts from the solid waste residue showed high antimicrobial activity against Aspergillus niger, Alternaria alternata, Penicillium chrysogenum, Bacillus sp., and Pseudomonas aeroginosa strains, at 0.75–6.0 μg/mL, 0.08–0.125 μg/mL, and 0.05–4.0 μg/mL, respectively.

LAVENDER ESSENTIAL OIL FOR SPINAL PAIN IN OBESE WOMEN: A CLINICAL TRIAL

ABSTRACT Objective To analyze the effect of lavender essential oil associated with massage on spinal pain levels in obese women. Methods The sample included 49 obese women, between 20 and 60 years of age, randomly assigned to three groups: control (n=15), intervention (n=19) and placebo (n=15). The intervention and placebo groups were submitted to eight 35-minute sessions, twice a week for one month, but the essential oil of Lavandula angustifolia was used only in the intervention group. A placebo was used for the placebo group and the control group received no intervention. Pain levels were measured before and after the intervention using the Visual Analog Scale. Results There was a significant decrease in total spinal pain (p=0.004), in the cervical region (p=0.003) and in the lumbar region (p=0.008) in the intervention group. Conclusion Lavender essential oil had a positive impact on the reduction of pain in the spine of obese women, as well as in the specific areas of the cervical and lumbar regions compared to the control and placebo groups. Level of evidence I; Randomized clinical trial.

Chemical Profile, Antioxidant Capacity, and Antimicrobial Activity of Essential Oils Extracted from Three Different Varieties (Moldoveanca 4, Vis Magic 10, and Alba 7) of Lavandula angustifolia

Chemical composition, antioxidant capacity, and antimicrobial activity of lavender essential oils (LEOs) extracted from three different varieties of Lavandula angustifolia Mill. (1-Moldoveanca 4, 2-Vis magic 10, and 3-Alba 7) have been determined. These plants previously patented in the Republic of Moldova were cultivated in an organic agriculture system in the northeastern part of Romania and then harvested in 3 consecutive years (2017-2019) to obtain the essential oils. From the inflorescences in the complete flowering stage, the LEOs were extracted by hydrodistillation. Then, their composition was analyzed by gas chromatography coupled with mass spectrometry (GC-MS) and by Fourier Transformed Infrared spectroscopy (FT-IR). The major identified constituents are as follows: linalool (1: 32.19-46.83%; 2: 29.93-30.97%; 3: 31.97-33.77%), linalyl acetate (1: 17.70-35.18%; 2: 27.55-37.13%; 3: 28.03-35.32%), and terpinen-4-ol (1: 3.63-7.70%; 2: 3.06-7.16%; 3: 3.10-6.53%). The antioxidant capacity as determined by ABTS and DPPH assays indicates inhibition, with the highest activity obtained for LEO var. Alba 7 from 2019. The in vitro antimicrobial activities of the LEOs and combinations were investigated as well, by using the disk diffusion method and minimum inhibitory concentration (MIC) against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538), Gram-negative Pseudomonas aeruginosa (ATCC 27858), Escherichia coli (ATCC 25922), the yeast Candida albicans (ATCC 10231), and clinical isolates. Our results have shown that LEOs obtained from the three studied varieties of L. angustifolia manifest significant bactericidal effects against tested microorganisms (Staphylococcus aureus and Escherichia coli), and antifungal effects against Candida albicans. The mixture of LEOs (Var. Alba 7) and geranium, respectively, in tea tree EOs, in different ratios, showed a significant enhancement of the antibacterial effect against all the studied strains, except Pseudomonas aeruginosa.

Effect of Massage With Lavender Oil on Postoperative Pain Level of Patients Who Underwent Gynecologic Surgery: A Randomized, Placebo-Controlled Study

This was a randomized, placebo-controlled study. The sample consisted of 3 groups of patients: an experimental group, massage application with lavender oil (n = 15); a placebo group, massage application with ultrasound gel (n = 15); and a control group (n = 15). Massage application was performed 3 hours after analgesic application. Pain levels of the patients in the experiment and placebo groups were evaluated with a Verbal Rating Scale (VRS) at the 30th minute and the 3rd hour after the application. Similarly, the pain level of patients in the control group was also evaluated with the VRS at 3 hours after the initial analgesic administration and following the 30th minute and the 3rd hour. Generally, the VRS scores of the 3 groups did not show a significant difference in terms of group and time interaction (P = .221). However, there was a significant difference in VRS scores between the experimental and control groups at the 30th minute after the massage (P = .036). This difference was caused by the lower pain level of the group, which had massage with lavender (2.66 ± .89) compared with the control group (3.80 ± 1.01). According to the study results, while only hand massage application after gynecologic surgery was effective for a short period in decreasing postoperative pain, it was determined that massage application with lavender had a longer effect in decreasing postoperative pain. The results of this study showed that this inexpensive and easy-to-apply method can be safely performed by nurses on postoperative patients and can support pain management of patients in the first hours after gynecologic surgery.

Post-Harvest Enhancing and Botrytis cinerea Control of Strawberry Fruits Using Low Cost and Eco-Friendly Natural Oils

This work investigates an experimental study for using low-cost and eco-friendly oils to increase the shelf life of strawberry fruit. Three natural oils were used: (i) Eucalyptus camaldulensis var obtuse, (ii) Mentha piperita green aerial parts essential oils (EOs), and (iii) Moringa oleifera seeds n-hexane fixed oil (FO). Furthermore, a mixture of EOs from E. camaldulensis var obtusa and M. piperita (1/1 v/v) was used. The treated fruits were stored at 5 °C and 90% relative humidity (RH) for 18 days. HPLC was used to analyse the changes in phenolic compounds during the storage periods. The effects of biofumigation through a slow-release diffuser of EOs (E. camaldulensis var obtusa and M. piperita), or by coating with M. oleifera FO, were evaluated in terms of control of post-harvest visual and chemical quality of strawberry fruits. The post-harvest resistance of strawberry fruits to Botrytis cinerea fungal infection was also evaluated. As a result, the EO treatments significantly reduced the change in visual and chemical quality of strawberry fruit. Additionally, changes in the titratable acidity of moringa FO-coated strawberry fruits were delayed. EO treatments improved total soluble solids, total phenols, ascorbic acid, antioxidants and peroxidase. E. camaldulensis var obtusa and M. piperita (1/1 v/v) EO-vapour fruit exhibited a slower rate of deterioration, compared to other treatments in all tested, in two experiments. The lowest colour change (ΔE) was observed inthe fruit treated with E. camaldulensis var obtusa EO and M. oleifera FO. HPLC showed changes in phenolic compounds’ concentration, where p-coumaric acid, caffeic acid, gallic acid, ferulic acid and ellagic acid were mostly identified in the fruits treated with the oils. SEM examination confirmed the potential decrease in fungal growth as the fruits were treated with EOs. In conclusion, the treatment of EOs during different storage periods showed promising characterisations for strawberry fruit quality.

Assessment of Physicochemical Characteristics and Microbiological Quality in Broiler Chicken Breast Muscle (Pectoralis major) Subjected to Different Temperatures and Lengths of Cold Transportation

Cold truck transportation is considered one of the most integral parts in a food processing chain. However, countless cases of product spoilage and food poisoning incidents have proven that temperature control during transport has been neglected. Literature on the impact of temperature during distribution is scarce. The objective of this study was to investigate the impact of various transportation temperatures and travel duration on the meat quality and microbial population of broiler chicken breast muscle. Sixty broiler chickens (42 days old) were slaughtered and eviscerated; they then had their breast muscles removed (each bird provided two breast muscle samples: left breast and right breast), which were wrapped in plastic film. All 120 packed boneless breasts (PBBs) were then placed at −18 °C for 24 h. After 24 h, the 60 PBB samples were subjected to transportation for 1 h at 4 °C (20 PBBs), 10 °C (20 PBBs), and 15 °C (20 PBBs) while the remaining 60 samples were transported for 5 h at 4 °C (20 PBBs), 10 °C (20 PBBs), and 15 °C (20 PBBs) before analyses. The samples transported at higher temperatures exhibited higher populations of coliform and Salmonella than those transported at lower temperatures. A significant impact of the transportation duration on the Salmonella population was only observed in samples transported at 4 °C for 5 h. However, a significant impact of transportation temperature on color was only recorded for the redness (a*) values, where the samples transported at higher temperatures exhibited higher redness (a*) values. Significant increases in lightness (L*) and yellowness (b*) values as well as decreases in redness (a*) and pH values were recorded in samples subjected to longer durations of transportation across all the temperatures observed in this study.

Essential oil of Cymbopogon martini, source of geraniol, as a potential antibacterial agent against Bacillus subtilis, a pathogen of the bakery industry

Background: Bacteria can adhere and grow on any surface due to their chemical and physical interaction, leading to the development of biofilms. Essential oils have a great potential for use in the food industry, as they can effectively prevent the presence of some pathogenic microorganisms.  Species such as those in the Bacillus genus have the ability to produce toxins. Some strains of Bacillus subtilis have been related to cases of food-borne diseases. In the bakery industry, B. subtilis also has been related to "rope" disease, linked to bread preservation processes. Methods: The aim of the study was to analyse the antibacterial properties of 24 chemotyped essential oils against the growth of B. subtilis. The biological activity study was carried out using disk diffusion in agar and broth dilution methods. Results: The essential oil of Cymbopogon martinii var. motia had a high geraniol content (>80.53%) and showed a high antimicrobial effect against the Gram-positive bacterium B. subtilis. Binary combinations of Cymbopogon martinii var. motia oil with Eugenia caryophyllus showed antagonistic effects on B. subtilis. Conclusions:  The essential oil of Cymbopogon martinii var. motia has an interesting potential use in the bakery industry as a preservative, in applications such as nano encapsulation for bakery doughs, active packaging of baked products, or surface disinfectants.

Essential oil of Cymbopogon martini, source of geraniol, as a potential antibacterial agent against Bacillus subtilis, a pathogen of the bakery industry

Background: Bacteria can adhere and grow on any surface due to their chemical and physical interaction, leading to the development of biofilms. Essential oils have a great potential for use in the food industry, as they can effectively prevent the presence of some pathogenic microorganisms.  Species such as those in the Bacillus genus have the ability to produce toxins. Some strains of Bacillus subtilis have been related to cases of food-borne diseases. In the bakery industry, B. subtilis also has been related to "rope" disease, linked to bread preservation processes. Methods: The aim of the study was to analyse the antibacterial properties of 24 chemotyped essential oils against the growth of B. subtilis. The biological activity study was carried out using disk diffusion in agar and broth dilution methods. Results: The essential oil of Cymbopogon martinii var. motia had a high geraniol content (>80.53%) and showed a high antimicrobial effect against the Gram-positive bacterium B. subtilis. Binary combinations of Cymbopogon martinii var. motia oil with Eugenia caryophyllus showed antagonistic effects on B. subtilis. Conclusions:  The essential oil of Cymbopogon martinii var. motia has an interesting potential use in the bakery industry as a preservative, in applications such as nano encapsulation for bakery doughs, active packaging of baked products, or surface disinfectants.

The impact of Qodume Shirazi seed mucilage-based edible coating containing lavender essential oil on the quality enhancement and shelf life improvement of fresh ostrich meat: An experimental and modeling study

Today, food consumers prefer to use the foods that contain natural preservatives. The purpose of this study was to investigate the effect of Qodume Shirazi seed mucilage (QSSM) and lavender essential oil (LO) on the preservation of ostrich meat during cold storage. The chemical compounds of LO were identified through gas chromatography-mass spectrometry (GC/MS). The ostrich meat samples were coated with the mucilage containing the essential oil at concentrations of 0%, 0.5%, 1%, 1.5%, and 2%, v/v. The control and the coated ostrich meat samples were kept at 4°C and analyzed for microbiological (total viable count, psychrotrophic count, Escherichia coli, Staphylococcus aureus, coliforms, and fungi), physicochemical (moisture content, pH, texture, and color parameters), and sensorial (odor, color, and total acceptance) characteristics during 9 days of storage. GC/MS identified 12 compounds in the essential oil, among which linalool was the major one (43.3%). The lightness (L* value) and hardness of all the ostrich meat samples were reduced during the storage. From a microbiological point of view, the cold storage duration for the control and the coated sample without the essential oil was only 3 days, while for coated samples containing 0.5%, 1%, 1.5%, and 2% essential oil, it was 3, 3, 6, and 9 days, respectively. The coated ostrich meat containing 2% LO had an appropriate quality with an expanded shelf life. The results showed that neural network with 10 neurons in the hidden layer had the lowest mean squared error and mean absolute error and the highest correlation coefficient for predicting the quality and microbial properties of the coated meat samples during storage.

Aroma Characteristics of Lavender Extract and Essential Oil from Lavandula angustifolia Mill

Lavender and its products have excellent flavor properties. However, most studies focus on the aroma profiles of lavender essential oil (LEO). The volatiles in lavender extracts (LEs), either in volatile compositions or their odor characteristics, have rarely been reported. In this study, the odor characteristics of LEs and LEO were comprehensively investigated by gas chromatography-mass spectrometry (GC-MS), coupled with sensory evaluation and principal chemical analysis (PCA). In addition, the extraction conditions of lavender extracts from inflorescences of Lavandula angustifolia Mill. were optimized. Under the optimal conditions of extraction, twice with 95% edible ethanol as the solvent, the LEs tended to contain the higher intensity of characteristic floral, herbal and clove-like odors as well as higher scores of overall assessment and higher amounts of linalool, linalool oxides I and II, linalyl acetate, lavandulyl acetate and total volatiles than LEO. PCA analysis showed that there were significant differences on the odor characteristics between LEO and LEs. The LEO, which was produced by steam distillation with a yield of 2.21%, had the lower intensity of floral, clove-like, medicine-like, pine-like and hay notes, a lower score of overall assessment and lower levels of linalool oxides I and II, linalyl acetate, lavandulyl acetate and total volatiles compared with LEs, whereas the relative contents of linalool and camphor in LEO were significantly higher than that in LEs. Furthermore, the earthy, green and watery odors were only found in LEO. Concerning the odor characteristics and volatile compositions, the LEs had better odor properties than LEO. These results provided a theoretical basis for the industrial preparation of lavender-related products.

Application of essential oils as antimicrobial agents against spoilage and pathogenic microorganisms in meat products

Meat and meat products are perishable products that require the use additives to prevent the spoilage by foodborne microorganisms and pathogenic bacteria. Current trends for products without synthetic preservatives have led to the search for new sources of antimicrobial compounds. Essential oils (EOs), which has been used since ancient times, meet these goals since their effectiveness as antimicrobial agents in meat and meat products have been demonstrated. Cinnamon, clove, coriander, oregano, rosemary, sage, thyme, among others, have shown a greater potential to control and inhibit the growth of microorganisms. Although EOs are natural products, their quality must be evaluated before being used, allowing to grant the Generally Recognized as Safe (GRAS) classification. The bioactive compounds (BAC) present in their composition are linked to their activity, being the concentration and the quality of these compounds very important characteristics. Therefore, a single mechanism of action cannot be attributed to them. Extraction technique plays an important role, which has led to improve conventional techniques in favour of green emerging technologies that allow to preserve better target bioactive components, operating at lower temperatures and avoiding as much as possible the use of solvents, with more sustainable processing and reduced energy use and environmental pollution. Once extracted, these compounds display greater inhibition of gram-positive than gram-negative bacteria. Membrane disruption is the main mechanism of action involved. Their intense characteristics and the possible interaction with meat components make that their application combined with other EOs, encapsulated and being part of active film, increase their bioactivity without modifying the quality of the final product.

Extraction of Essential Oils from Medicinal Plants and their Utilization as Food Antioxidants

BACKGROUND

The use of essential oils is receiving increasing attention worldwide, as these oils are good sources of several bioactive compounds. Nowadays essential oils are preferred over synthetic preservatives thanks to their antioxidant and antimicrobial properties. Several studies highlight the beneficial effect of essential oils extracted from medicinal plants to cure human diseases such as hypertension, diabetes, or obesity. However, to preserve their bioactivity, the use of appropriate extraction technologies is required.

METHODS

The present review aims to describe the studies published so far on the essential oils focusing on their sources and chemical composition, the technologies used for their recovery and their application as antioxidants in food products.

RESULTS

The review has been structured in three parts. In the first part, the main compounds present in essential oils extracted from medicinal plants have been listed and described. In the second part, the most important technologies used for extraction and distillation, have been presented. In detail, conventional methods have been described and compared with innovative and green technologies. Finally, in the last part, the studies related to the application of essential oils as antioxidants in food products have been reviewed and the main findings discussed in detail.

CONCLUSION

In summary, an overview of the aforementioned subjects is presented by discussing the results of the most recent published studies.

Chemical Investigation and Screening of Anti-Proliferative Activity on Human Cell Lines of Pure and Nano-Formulated Lavandin Essential Oil

Lavandin essential oil (LEO), a natural sterile hybrid obtained by crossbreeding L. angustifolia × L. latifolia, is mainly composed by active components belonging to the family of terpenes endowed with relevant anti-proliferative activity, which can be enhanced by proper application of nanotechnology. In particular, this study reports the chemical characterization and the screening of the anti-proliferative activity on different human cell lines of pure and nano-formulated lavandin essential oil (EO). LEO and its formulation (NanoLEO) were analyzed by HS/GC-MS (Headspace/Gas Chromatography-Mass Spectrometry) to describe and compare their chemical volatile composition. The most abundant compounds were linalool and 1,8-cineole (LEO: 28.6%; 27.4%) (NanoLEO: 60.4%; 12.6%) followed by α-pinene (LEO: 9.6%; NanoLEO: 4.5%), camphor (LEO: 6.5%; NanoLEO: 7.0%) and linalyl acetate (LEO: 6.5%; NanoLEO: 3.6%). The cytotoxic effects of LEO and NanoLEO were investigated on human neuroblastoma cells (SHSY5Y), human breast adenocarcinoma cells (MCF-7), human lymphoblastic leukemia cells (CCRF CEM), human colorectal adenocarcinoma cells (Caco-2) and one normal breast epithelial cell (MCF10A) by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide)-assay. Caco-2, MCF7 and MCF10A normal cells resulted more resistant to the treatment with LEO, while CCRF-CEM and SHSY5Y cells were more sensitive. The antiproliferative effect of LEO resulted amplified when the essential oil was supplied as nanoformulation, mainly in Caco-2 cells. Scanning and transmission electron microscopy investigations were carried out on Caco-2 cells to outline at ultrastructural level possible affections induced by LEO and NanoLEO treatments.

Comparative Effects of Carum copticum Essential Oil on Bacterial Growth and Shiga-Toxin Gene Expression of Escherichia coli O157:H7 at Abused Refrigerated Temperatures

Abused refrigerated temperatures are described as unacceptable deviations from the optimal temperature, occurring frequently during transportation of food products. Escherichia coli O157:H7 is a serious contaminant of meats and meat products due to its ability to grow at abused temperatures (> 10 °C). The aim of this study was to evaluate the antibacterial activity of Carum copticum essential oil for the control of Escherichia coli O157:H7 using laboratory media and minced beef at severe abused refrigerated temperature (15 °C). A comparative quantitative reverse transcription real-time PCR was used to assess effects of temperature and Carum copticum essential oil at sub-minimum inhibitory concentrations on bacterial growth and Shiga-toxin gene (stx1A and stx2A) expression. Results indicated that Carum copticum essential oil inhibited growth of E. coli O157:H7 in tryptone soy broth (TSB) media at all sub-MIC values until Hour 48. However, bacterial population increased progressively until Hour 72 at essential oil concentration of 0.75% (ml g^-1) and reached 8.6 log CFU g^-1 in minced beef. The essential oil at concentration of 0.005% (ml g^-1) increased stx gene expression at all times, but increased stx gene expression (0.015%) at Hour 24 in TSB media. The expression rate of stx1A in minced beef decreased progressively (10.39 and 7.67 folds for 0.5 and 0.75%, respectively) and expression of stx2A was variable in minced beef during storage. In conclusion, results from this study have shown that effects of Carum copticum essential oil on growth and virulence gene expression are not necessarily correlated and temperature, essential oil concentration, investigated gene type, and bacterial growth environment (in vivo or in vitro) are effective as well.

Assessment of the Toxicity of Natural Oils from Mentha piperita, Pinus roxburghii, and Rosa spp. Against Three Stored Product Insects

Three natural oils extracted from Mentha piperita, Pinus roxburghii, and Rosa spp. were assessed in order to determine their insecticidal activity against the adults of three stored product insects: the rice weevil (Sitophilus oryzae L.), the lesser grain borer (Rhyzopertha dominica, Fabricius), and the red flour beetle (Tribolium castaneum, Herbst.). By Gas chromatography–mass spectrometry (GC/MS) analysis, the main compounds in the n-hexane oil from Rosa spp. were determined to be methyl eugenol (52.17%), phenylethyl alcohol (29.92%), diphenyl ether (7.75%), and geraniol (5.72%); in the essential oil from M. piperita, they were menthone (20.18%), 1,8-cineole (15.48%), menthyl acetate (13.13%), caryophyllene (4.82%), β-pinene (4.37%), and D-limonene (2.81%); and from the foliage of P. roxburghii, they were longifolene (19.52%), caryophyllene (9.45%), Δ-3-carene (7.01%), α-terpineol (6.75%), and γ-elemene (3.88%). S. oryzae and R. dominica were reared using sterilized wheat grains, and T. castaneum was reared on wheat flour mixed with yeast (10:1, w/w), all under laboratory conditions (27 ± 1 °C and 65% ± 5% Relative humidity (R.H). Two toxicity bioassays were used, as well as contact using thin film residues and fumigation bioassays. The results indicated that M. piperita caused a high toxicity for S. oryzae compared to other insects. High significant variations were observed between the tested M. piperita doses against the stored insects, and this natural material could be used to control insects that infect the grains. Also, the data indicated that the Rosa spp. oil had a low-toxicity effect against these insects compared to other oils. We recommend using natural oils against the stored weevils and petals, rather than the chemical agent, so as to serve human health.

Lavender (Lavandula angustifolia Mill.) Essential Oil Alleviates Neuropathic Pain in Mice With Spared Nerve Injury

Low treatment efficacy represents an important unmet need in neuropathic pain patients and there is an urgent need to develop a more effective pharmacotherapy. An increasing number of patients choose complementary medicine to relieve pain. Lavender essential oil (LEO) is approved by the European Medicines Agency as herbal medicine to relieve anxiety and stress. However, the capability of LEO to relieve other nervous system disorders such as neuropathic pain has never been established. Our work aimed to evaluate the antineuropathic properties of lavender on a spared nerve injury (SNI) model of neuropathic pain in mice. An acute oral administration of LEO (100 mg/kg) alleviated SNI-induced mechanical allodynia, evaluated in the von Frey test, with an intensity comparable to the reference drug pregabalin. Investigations into the mechanism of action showed that LEO markedly decreased the phosphorylation of ERK1, ERK2, and JNK1, and decreased the levels of iNOS in the spinal cord; involvement of the endocannabinoid system was also detected using in vitro inhibition of the FAAH and MALG enzymes as well as in vivo experiments with the CB1 antagonist. Conversely, no effect on P38 phosphorylation and NF-kB activation was detected. These antihyperalgesic effects appeared at the same dose able to induce antidepressant-like, anxiolytic-like, and anorexic effects. In addition, gavage with LEO did not significantly alter animals' gross behavior, motor coordination, or locomotor activity, nor impaired memory functions. Oral administration of LEO could represent a therapeutic approach in the management of neuropathic pain states.

Chemical Compositions of the Volatile Oils and Antibacterial Screening of Solvent Extract from Downy Lavender

The discovery of a new species exhibiting more effective antibacterial properties is necessary because of the demand on Lavandula species, which continues to increase in a variety of industries. Lavandula pubescens might be a good alternative, as it exhibits strong antibacterial activity. In this study, the chemical composition of the essential oils from different organs (flowers, leaves, stems, and roots) of L. pubescens was identified using gas chromatography-mass spectrometry. Furthermore, the antimicrobial activities of different solvent extracts (methanol, ethanol, diethyl ether, hexane, and ethyl acetate) and different organ (flower, leaf, stem, and root) extracts of L. pubescens were evaluated. Only the ethyl acetate extracts of L. pubescens exhibited antibacterial activity against all bacterial strains tested, including Staphylococcus haemolyticus, Escherichia coli (KF 918342), Aeromonas hydrophila (KCTC 12487), E. coli (ATCC 35150), Cronobacter sakazakii (ATCC 29544), and Aeromonas salmonicida (KACC 15136). In particular, the extracts exhibited significant activity against S. haemolyticus. Ethyl acetate extract of the leaf exhibited the best activity against all bacterial strains. This study provides valuable information on the chemical compositions in essential oils and antimicrobial properties of L. pubescens.

An investigation of the effect of Zataria multiflora Boiss and Mentha piperita essential oils to improve the chemical stability of minced meat

Background and Aim:

Extending the shelf life of foods is an essential concept in food safety. Most of the time, foods deteriorate through the growth of microorganisms or oxidation process. Essential oils (EOs) derived from plant material have well-documented antioxidant and antibacterial activity. This study aimed to evaluate the effect of Zataria multiflora Boiss EO (ZEO) and Mentha piperita EO (MEO) on the chemical stability of minced meat during storage at 7°C.

Materials and Methods:

Total phenolic content, β-Carotene bleaching test, ferric reducing antioxidant potential assay, and 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity were used to determine the antioxidant potential of EOs. Five different groups including control, ZEO 0.3%, ZEO 0.5%, MEO 0.3%, and MEO 0.5% were designed to assess the chemical stability of minced meat by measuring pH, thiobarbituric acid (TBA), total volatile base nitrogen (TVBN), and peroxide value (PV).

Results:

pH did not have any significant change during storage. TBA values in the control group were significantly higher than the treatment groups, especially from the 5^th day of storage. TVBN in the treatment group was significantly lower than the control group during storage. PV values in the treatment group were significantly lower than the control group during storage.

Conclusion:

Results indicate that ZEO and MEO had an excellent antioxidant activity and retarded the spoilage process in minced meat.

Plants of the Genus Lavandula: From Farm to Pharmacy

The Lavandula genus, belonging to the Lamiaceae, includes 39 species, with nearly 400 registered cultivars. Lavandula are worldwide plants that occur over the Mediterranean, Europe, North Africa, southwest Asia to southeast India. Lavandula plants have been used since ancient time to flavor and preserved food, to treat diseases including wound healing, sedative, antispasmodic, microbial and viral infections. Numerous researches have described the chemical composition and the primary components of lavender oils are the monoterpenoids (linalool, linalyl acetate, 1,8-cineole, β-ocimene, terpinen-4-ol, and camphor), sesquiterpenoids (β-caryophyllene and nerolidol) and other terpenoid compounds (e.g., perillyl alcohol). The high concentrations of linalyl acetate make them attractive in perfumery, flavoring, cosmetics and soap industries. Currently, data on the antimicrobial activity of lavender plants have been scientifically confirmed. Indeed, lavender essential oils possess wide spectra of biological activities such as antispasmodic, carminative, analgesic, sedative, hypotensive, antiseptic, antimicrobial, antifungal, antidiuretic and general tonic action. In addition, clinical studies support their uses as treatment of health conditions. However, further clinical studies are necessary to define the magnitude of the efficacy, mechanisms of action, optimal doses, long-term safety, and, potential side effects of lavender plants.

Prospective of Essential Oils of the Genus Mentha as Biopesticides: A Review

Mentha is a genus from the family Lamiaceae, whose essential oils has long been used in various forms such as in management of plant pathogens and insect pests, in traditional medicine as well as in culinary and cosmetics. Its major chemical components such as menthol, carvone have now been successfully commercialized in the industry as antimicrobials/insecticidal agents. Current review focuses on chemical composition of essential oils of some Mentha species from different geographical regions with their insecticidal (repellent, antifeedant, and ovicidal) and antimicrobial efficacies against bacterial, fungal plant pathogens and insects of stored products. Reports of the researchers on chemical analysis of essential oils of Mentha species revealed that most of the oils being rich in pulegone, menthon, menthol, carvone, 1, 8-cineole, limonene and β-caryophyllene. Reviewed literature revealed that, essential oils from different Mentha species possess potential antimicrobial activity against plant pathogens and have insecticidal activity against stored product insects. Thus, antimicrobial and insecticidal properties of essential oils of Mentha species offer the prospect of using them as natural pesticides with a commercial value, having social acceptance due to its sustainability and being environment friendly.

Volatile Oils of Nepeta tenuifolia (Jing Jie) as an Alternative Medicine against Multidrug-Resistant Pathogenic Microbes

Essential oils from the dried spikes of Nepeta tenuifolia (Benth) are obtained by steam distillation. Pulegone was identified as the main component in the spikes of N. tenuifolia through analysis, with greater than 85% purity obtained in this study. The essential oils are extremely active against all Gram-positive and some Gram-negative reference bacteria, particularly Salmonella enterica, Citrobacter freundii, and Escherichia coli. The minimum inhibitory concentration was found to be between 0.08 and 0.78% (against S. enterica), 0.39 and 0.78% (against C. freundii), and 0.097 and 0.39% (against E. coli), whereas the minimum bactericidal concentration varied in range from 0.097% to 1.04%. In general, the essential oils show a strong inhibitory action against all tested reference strains and clinical isolates. However, the antibacterial activity of EOs against both Pseudomonas aeruginosa reference strains and clinical isolates was relatively lower than other Gram-negative pathogens. The essential oils of N. tenuifolia also displayed bactericidal activities (MBC/MIC < 4) in this study. These findings reflect the bactericidal activity of the essential oils against a wide range of multidrug-resistant clinical pathogens in an in vitro study. In addition, we propose the fragmentation pathways of pulegone and its derivatives by LC-ESI-MS/MS in this study.