Mint Essential Oil Research Articles

Essential Oils of Mentha arvensis and Cinnamomum cassia Exhibit Distinct Antibacterial Activity at Different Temperatures In Vitro and on Chicken Skin.

The bacterial contamination of meat is a global concern, especially for the risk of Salmonella infection that can lead to health issues. Artificial antibacterial compounds used to preserve fresh meat can have negative health effects. We investigated the potential of natural essential oils (EOs), namely Mentha arvensis (mint) and Cinnamomum cassia (cinnamon) EOs, to prevent contamination of the food pathogen, Salmonella enterica subsp. enterica serotype Typhimurium, in vitro and on chicken skin. The gas chromatography-mass spectrometry (GC-MS) technique was used to determine the compositions of mint EO (MEO) and cinnamon EO (CEO); the most abundant compound in MEO was menthol (68.61%), and the most abundant compound was cinnamaldehyde (83.32%) in CEO. The antibacterial activity of MEO and CEO were examined in vapor and direct contact with S. typhimurium at temperatures of 4 °C, 25 °C, and 37 °C. The minimal inhibitory concentration at 37 °C for MEO and CEO reached 20.83 µL/mL, and the minimal bactericidal concentration of CEO was the same, while for MEO, it was two-fold higher. We report that in most tested conditions in experiments performed in vitro and on chicken skin, CEO exhibits a stronger antibacterial effect than MEO. In the vapor phase, MEO was more effective against S. typhimurium than CEO at 4 °C. In direct contact, the growth of S. typhimurium was inhibited more efficiently by MEO than CEO at small concentrations and a longer exposure time at 37 °C. The exploration of CEO and MEO employment for the inhibition of Salmonella bacteria at different temperatures and conditions expands the possibilities of developing more environment- and consumer-friendly antibacterial protection for raw meat.

Impact of different drying approaches on VOCs and chemical composition of Mentha spicata L. essential oil: A combined analysis of GC/MS and E-nose with chemometrics methods

Given the significance spearmint (Mentha spicata L.), there is an increased demand for dry medicines and high-quality aromatic mint. In this study, a non-destructive technique based on electronic nose was used in combination with a GC/MS method and chemometrics to determine the quality of spearmint essential oil under eight drying methods. It was found that hot air drying (HAD) method yielded the highest amount of essential oil and its compounds. So that its highest amount was obtained in HAD1a method and equal to 1.380%. However, the amount decreased with increasing drying temperature and air velocity. In addition, sun drying performed worst its value was equal to 0.663%. The highest percentage of the obtained essential oil compounds was related to the three main components of carvone (64.30–7.45%), limonene (24.21–6.59%), and carveol (18.34–1.92%). Furthermore, the Nu-SVM classification algorithm with the sigmoid function provided an accuracy of 0.975 for classifying eight essential oil groups. In light of the limited knowledge about the effects of drying on the qualitative and quantitative characteristics of medicinal plants, a new method for essential oil evaluation was proposed in this study. The results could provide a theoretical reference to choose the best drying method and quickly determine the quality of mint essential oils.

Anti-oomycete activities from essential oils and their major compounds on Phytophthora infestans

Botanicals are various plant-based products like plant extracts or essential oils. Anti-fungal activities of selected essential oils were tested on the pathogen causing potato and tomato late blight (Phytophthora infestans). Tests to evaluate anti-oomycete activities of commercial essential oils and their major compounds were carried out in vitro in microplate in liquid media. Anti-oomycete activities on Phytophthora infestans strain were obtained from essential oils/major compounds: Eucalyptus citriodora/citronellal; Syzygium aromaticum (clove)/eugenol; Mentha spicata/D-Carvone, L-Carvone; Origanum compactum/carvacrol; Satureja montana (savory)/carvacrol; Melaleuca alternifolia (tea tree)/terpinen-4-ol, and Thymus vulgaris/thymol. As an active substance of mineral origin, copper sulfate was chosen as a control. All selected essential oils showed an anti-oomycete activity calculated with IC50 indicator. The essential oils of clove, savory, and thyme showed the best anti-oomycete activities similar to copper sulfate, while oregano, eucalyptus, mint, and tea tree essential oils exhibited significantly weaker activities than copper sulfate. Clove essential oil showed the best activity (IC50 = 28 mg/L), while tea tree essential oil showed the worst activity (IC50 = 476 mg/L). For major compounds, three results were obtained: they were statistically more active than their essential oils (carvacrol for oregano, D- and L-Carvone for mint) or as active as their essential oils sources (thymol for thyme, carvacrol for savory, terpinen-4-ol for tea tree) or less active than their original essential oils (eugenol for clove, citronellal for eucalyptus). Microscopical observations carried out with the seven essential oils showed that they were all responsible for a modification of the morphology of the mycelium. The results demonstrated that various essential oils show different anti-oomycete activities, sometimes related to a major compound and sometimes unrelated, indicating that other compounds must play a role in total anti-oomycete activity.

Determination of the Potential for use of Plant Essential Oils as a Fungicide Against Fusarium Oxysporum (OG10)

This study aimed to determine whether the essential oils of thyme, ginger, and mint from medicinal aromatic plants can provide resistance to the pathogen Fusarium oxysporum in the maize plant. To this end, the antifungal effect of 0.1 ml, 0.25 ml, 0.5 ml, and 1 ml essential oil amounts was determined by the agar disc diffusion method. It was determined that concentrations containing 0.1, and 0.25 ml essential oil showed no antifungal effects, however, concentrations containing 0.5 and 1 ml essential oil had antifungal effects. The most effective concentration was found to be 1 ml of essential oil in all three species. The maize was grown under hydroponic conditions. Thyme, ginger, and mint essential oils (1 g/100 ml) were applied to the root medium of the grown maize plant on the 8th day. An F. oxysporum suspension containing 107 spores was applied after 24 hours and harvested 3 days later. When the reactive oxygen species (H2O2) and MDA amounts of the harvested plants were examined, it was observed that there was an increase in the population of F. oxysporum. However, applications of thyme, ginger, and mint essential oil have been observed to significantly reduce these. It was also determined that essential oils protected the plant against F. oxysporum by increasing antioxidant enzyme activities. Although these three essential oils applied have antifungal properties, it has been observed that the best effect belongs to thyme essential oil. The results show that essential oils of thyme ginger and mint can be used as potential fungicides against the pathogen F. oxysporum in maize cultivation

Synthesis of Mint-flavor Microcapsules and Its Application in Cigarettes

By using microcapsule technology, the components that may react with each other can be made into microcapsule products respectively, so that they can be stabilized in a system, and each effective component can be released in an orderly manner and act at the corresponding time, thus improving the flavor and nutrition of the products. In order to further find an efficient and reasonable cigarette flavoring process, this study used gelatin and Arabic gum as composite wall materials to synthesize mint-flavored microcapsules by complex coacervation. Firstly, gelatin-Arabic gum dispersed peppermint oil in water medium to form micro-droplets, then the pH value of the system was adjusted, the solubility was reduced and condensed into capsules, and then glutaraldehyde was added for curing reaction. The test results show that the embedding efficiency of microcapsules is the highest when the mass ratio of mint essence to two sustained-release materials is 1:9. When the dosage of mint-flavor microcapsules is 10 ~ 15 mg/ cigarette, the aroma of cigarettes increases obviously, the irritation decreases, and the aroma of wild mint essential oil can also be coordinated with the cigarette aroma. The results show that the samples of mint-flavor microcapsules synthesized in this study greatly improve the aroma characteristics and smoking characteristics of cigarettes, which lays a foundation for the brand development of cigarettes and has a good application prospect.

ФИТОХИМИЧЕСКИЙ АНАЛИЗ, РАЗРАБОТКА СОСТАВА И ТЕХНОЛОГИИ КАРАНДАШЕЙ С ЭФИРНЫМ МАСЛОМ ЛИСТЬЕВ МЯТЫ ВОДНОЙ, ПРОИЗРАСТАЮЩЕЙ НА СЕВЕРНОМ КАВКАЗЕ

The leaves of water mint growing in the Northern Caucasus were chosen as an object of research. Earlier authenticity of water mint on external and anatomo-diagnostic signs with the purpose of distinction from close species was defined. Based on the results of qualitative reactions and quantitative determination (steam distillation method) in the leaves of water mint was detected essential oil, the content of which was 1,92%. The method of ascending chromatography on paper identified flavonoids: rutin, luteolin, hyperoside. The presence of flavonoids in the raw material was confirmed by cyanidine test (by pink staining) and the formation of a yellow-green complex (with a solution of aluminum chloride (III) 2% alcohol). The spectrophotometric method determined the content of the sum of flavonoids in terms of luteolin, which was 0,72±0,05%. The method of approximate-quantitative spectral analysis analyzed the content of chemical elements from the place of preparation of leaves of water mint in Chegemsky area of KBR. The research revealed 7 trace elements as additional sources possessing antiseptic; analgesic; antipyretic; anti-inflammatory; wound-healing, etc. properties. The optimal bases (beeswax, cocoa butter, paraffin, PEO-4000, PEO-400, tween-80, lanolin, peach oil) for medical pencils with aqueous mint essential oil were selected experimentally. For this purpose, 5 compositions of pencils with a model concentration of essential oil of 2% were selected. The technology of making pencils by pouring method was developed. The estimation of smearing and sticking ability of pencils was carried out. It is established, that the best smearing and sticking ability possesses a pencil of composition №5 which has been chosen as optimum for the further researches.

IN VITRO ANTIFUNGAL ACTIVITY OF ESSENTIAL OILS (FAMILY LAMIACEAE) AGAINST CLADOSPORIUM SP. STRAINS – POSTHARVEST PATHOGENS OF FRUITS

Essential oils (EOs) are a suitable alternative for extending the shelf life of foods. The aim of this research was to test the effect of fifteen EOs extracted from plants of the Lamiaceae family on five strains of Cladosporium cladosporioides. Cladosporium cladosporioides is frequently found on fruit and may be involved in fruit spoilage. The strains used in the study were isolated directly from lesions on berries. The growth of the fungi on the fruit was the reason for its rejection from sale. The antifungal activity of EOs against Cladosporium cladosporioides strains was determined by the microatmospheric method (625 μl EO/L air) during 14 days of cultivation. Thirteen EOs: thyme and red thyme (from Thymus vulgaris L.), mitcham mint (Mentha x piperita L. var. Mitcham), peppermint (Mentha x piperita L.), savory (Satureja hortensis L.), sage (Salvia officinalis L.), spearmint (Mentha spicata L. var. crispa), lavender (Lavandula angustifolia Mill.), marjoram (Origanum majorana L.), bergamot-mint (Mentha citrata Erh.), wild thyme (Thymus serpyllum L.), hyssop (Hyssopus officinalis L.), and oregano (Origanum vulgare L.) were shown to inhibit growth of all strains to 100%. Basil (Ocinum basilicum L.) and rosemary (Rosmarinus officinalis L.) EOs did not have a 100% inhibitory effect on all strains throughout the cultivation period. Subsequently, minimum inhibitory concentrations (MIDs) were determined using the microatmospheric method. LD90 and LD50 values were estimated by probit analysis. Based on the MID, LD90, and LD50 results, the essential oils can be divided into three groups. The first group (most effective): thyme, red thyme, spearmint, wild thyme, and oregano EO; the second group: peppermint, lavender, mitcham mint and savory EO; the third group: sage, marjoram, bergamot-mint and hyssop EO. The most effective EOs can be used to suppress the growth of Cladosporium cladosporioides in the vapour phase.

Composition and Anti-Helicobacter pylori Properties of Essential Oils Obtained from Selected Mentha Cultivars.

Helicobacter pylori infections are highly common amongst the global population. Such infections have been shown to be the cause of gastric ulcers and stomach carcinoma and, unfortunately, most cases are asymptomatic. Standard treatment requires antibiotics such as metronidazole or azithromycin to which many strains are now resistant. Mentha species have been used as a natural treatment for gastrointestinal diseases throughout history and essential oils (EOs) derived from these plants show promising results as potential antimicrobial agents. In this study, EOs obtained from the leaves and flowers of five cultivars of Mentha × piperita and M. spicata were examined by GC-MS. The investigated mints are representatives of four chemotypes: the menthol chemotype (M. × piperita 'Multimentha' and M. × piperita 'Swiss'), the piperitenone oxide chemotype (M. × piperita 'Almira'), the linalool chemotype (M. × piperita 'Granada'), and the carvone chemotype (M. spicata 'Moroccan'). The chemical composition of EOs from mint flowers and leaves was comparable with the exception of the Swiss cultivar. Menthol was the most abundant component in the leaves while menthone was highest in flowers. The H. pylori ATCC 43504 reference strain and 10 other H. pylori clinical strains were examined for their sensitivity to the EOs in addition to their major monoterpenoid components (menthol, menthone, carvone, dihydrocarvone, linalool, 1,8-cineole, and limonene). All tested mint EOs showed inhibitory activity against both the reference H. pylori ATCC 43504 strain (MIC 15.6-31.3 mg/L) and clinical H. pylori strains (MIC50/90 31.3-250 mg/L/62.5-500 mg/L). Among the reference monoterpenes, menthol (MIC50/90 7.8/31.3 mg/L) and carvone (MIC50/90 31.3/62.5 mg/L) had the highest anti-H. pylori activity, which also correlated with a higher activity of EOs containing these compounds (M. × piperita 'Swiss' and M. spicata 'Moroccan'). A synergistic and additive interaction between the most active EOs/compounds and antibiotics possibly points to a new plant-based anti-H. pylori treatment.

Biorational potential of Mentha essential oils of Indian origin: Comparative note on insecticidal efficacy, fumigant persistence, oviposition deterrence of Sitophilus oryzae

Natural compounds have widely gained their acceptance as biorationals for management of storing grain from insect pests. Mentha spp. are commercially important plant genus known for its distinct aroma. The present study is aimed towards the comparative insecticidal activity of four mint essential oils (Mentha arvensis, Mentha citrata, Mentha piperita and Mentha spicata) against rice weevil (Sitophilus oryzae). Further, the GC-MS analysis of mint essential oil’s (EO’s) exhibited diversity in aroma compounds, M. arvensis (menthol 61% and l-menthone 9.11%), M. citrata (linalool 36.74% and linalyl acetate 35.9%), M. piperita (menthol 36.28%, menthone 26.37% and iso-menthone 5.15%) and M. spicata (54.14% of carvone and 20.97% of limonene). Whereas, the M. spicata EO exhibited the strongest toxicity (fumigant and contact) in both with and without food conditions around 100% mortality for 25 μL dose within 24 h of exposure. The LC50 and LD50 values exhibited by M. spicata were 54.07 μL/L and 11.5 μL/100 cm2 respectively. Similarly, the concentrations of 2.5% and 5% of M. spicata EO also exhibited a strong fumigant and contact toxicity against S. oryzae within 24 h as compared to known prophylactic insecticide (0.3% of Deltamethrin). Besides, 100% oviposition deterrence exhibited by all the four mint EO’s and 56% of AChE inhibition is noticed for M. spicata EO. Furthermore, post-treated grains showed no persistence of mint aroma residues and the treated grains retained the seed viability. Thus, on a comparative note, the M. spicata EO possess potential biorational traits for the effective management of stored grain from insect pests.

Óleos essenciais no manejo de Alternaria alternata f. sp. citri em frutos de tangerineira ‘Dancy’

ABSTRACT Tangerines and their hybrids are affected by economically essential diseases. The Alternaria brown spot (Alternaria alternata f. sp. citri) deserves to be highlighted, as it is present in all tangerine production areas. This study aimed to determine the effect of essential oils on A. alternata f. sp. citri. The experiments were carried out in the Laboratories of Phytopathology and Biology and Technology of Post-Harvest of the Federal University of Paraíba, Areia, PB. Three pathogen isolates were used, and ten essential oils from grape, sunflower, eucalyptus, ginger, copaiba, mint, fennel, citronella, clove, and linseed at a concentration of 1%, diluted in potato dextrose agar for in vitro tests. The oils were diluted in distilled water for the fruit test, and the fruits were immersed in the treatments for 5 min. In addition, the fungicide Thiabendazole (400 mL/100L) and sterile distilled water were used as the control treatments. The fruits were inoculated with a conidia suspension of the pathogen (105 conidia/mL). Mycelial Growth Rate Index, colony diameter, spore production and dimensions, fruit disease severity, and enzymatic activity were evaluated. A completely randomized design was used, with 12 treatments and four replications in vivo. The results indicate that the essential oils of mint, eucalyptus, fennel, and citronella were efficient in the in vitro control of the pathogen, ultimately inhibiting the growth of fungal colonies. Eucalyptus oil efficiently managed A. alternata f. sp. citri on ‘Dancy’ tangerine fruits. Essential oils did not influence the enzymatic activity of the fruits.

Impact of essential oils on seed quality and seed-borne pathogens of Altheaofficinalis seeds of different ages

BackgroundThe cultivation of medicinal plants is a promising alternative to overcoming problems in the overharvesting of wild plants and ecosystem degradation. Cultivation depends upon two major factors: seed quality and the presence of seed-borne pathogens. Organic production of marshmallow plants (Altheaofficinalis L.) does not allow for the use of conventional pesticides. This study aimed to find an environmentally safe solution and the equilibrium between seed germination and the presence of fungal pathogens. The study was performed on a population of marshmallows which were cultivated for a period of 3 years (2018–2020) in Pančevo, The Republic of Serbia. The following six essential oils: Origanumvulgare L.,Cinnamomumcassia Presl.,Ocimumbasilicum L.,Carumcarvi L.,Menthapiperita L.,Lavandulaangustifolia Mill. at five concentrations (1%, 0.5%, 0.2%, 0.02%, 0.002%) were used for seed treatment along with water and PEG-40 (emulsifier) as controls. Germination, dormant seeds, dead seeds, abnormal seedlings and the presence of seed-borne pathogens were determined under laboratory conditions.ResultsAmong the aforementioned treatments using oregano, cinnamon, basil, caraway, mint, and lavender essential oils, the most effective treatment resulted with lavender essential oil at a concentration of 0.02% in 3-year-old seeds. The highest values for seed germination and dead seeds were 46% and 20% in 3-year-old seeds, respectively. This treatment increased seed germination by 13%, and seedling growth i.e., the growth of seedling stems and radicles by 24–35%, respectively. It also reduced the presence of seed-borne fungal pathogens from 53 to 100%.ConclusionsThe results revealed that an increase in seed germination rate and simultaneous reduction in seed-borne fungal infection was achieved with the lavender essential oil seed treatments. This is the first discovery of the stimulating effect of lavender essential oil on seed quality parameters. Furthermore, the study demonstrates its potential application in seed processing in the organic production of marshmallow plants.Graphical

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.

Antifungal Efficacy of Mint Essential Oil Against Penicillium spp. Inoculated on Carrots

Current research aims to investigate the chemical composition, antioxidant, and in vitro and in situ antifungal activities of commercially available Mentha arvensis essential oil (mint, MEO). The identification of the volatile substances was done using Gas chromatography–Mass spectrometry (GC-MS) analysis. A total of 42 components representing 99.5% of the total oil were identified. The main compounds in the oil were menthol (37.3%), menthone (17.4%), neo-menthol (14.1%), and 1,8-cineole (4.9%). Antioxidant assays (1,1-diphenyl-2-picrylhydrazyl radical) demonstrate only weak activity for the MEO in values 195.00 ± 5.30 μg TEAC.mL-1, with 22.8 ± 1.2% free radical-scavenging inhibition. Evaluation of in vitro and in situ antifungal activities of MEO (in four concentrations: 62.5 µL/L, 125 µL/L, 250 µL/L, and 250 µL/L) against three strains of Penicillium (P.) spp. fungi strains (P. expansum, P. citrinum, P. crustosum) were assessed by disc diffusion method and vapor contact method on the carrot as model food, respectively. The suitability of carrots as a substrate for analyzes was verified by determining moisture content (MC) and water activity (aw), which showed values of 82.80 ± 2.33% and 0.959 ± 0.001, respectively. MEO exhibited promising antifungal activity against analyzed strains of test fungi as a diameter of zones of inhibition (from 2.88 ± 0.55 to 12.33 ± 1.14 mm), as well as the effectiveness of this oil was detected on the carrot model (from -5.41 ± 7.35 to 100.00 ± 0.00%). Moreover, it can be concluded that the growth inhibition of fungi strains significantly depends (P < 0.05) on the concentration of the MEO used in both procedures. Our results suggest that MEO, as a promising natural antifungal agent, can be applied in the innovative packaging of food products including carrots.

Signal, Not Poison—Screening Mint Essential Oils for Weed Control Leads to Horsemint

Weed control tries to suppress competitors for a crop and often relies on differential intoxication, making use of differences in uptake, development, or metabolism. We explored the possibility of using natural signals to shift competition in favour of the crop. Using the competitive horsemint (Mentha longifolia) as a paradigm, we showed that essential oils from certain mint species suppress the seedling development of different target species in a specific and efficient manner. The specificity concerned both the donor and the receptor. We demonstrated further that the effect of horsemint oil was specific for actin filaments, and not for microtubules. Since the elimination of actin will impair auxin transport, which is essential for root regeneration in vegetatively propagating weeds, we tested the efficacy of horsemint essential oil in combination with a slow-release carrier against field bindweed (Convolvulus arvensis), a pertinent weed in organic cereal production. We observed that the development of this weed can be specifically blocked, especially if the carrier is worked into the soil. We propose that allelopathic interactions, often relying on manipulative chemical signalling, harbour significant potential for organic weed control.

Mint (Mentha): A Herb and Used as a Functional Ingredient

Health never goes out of trend. There is increased interest in alternative medicines particularly those obtained from plants. Functional foods have the ability to prevent or lessen the severity of symptoms of disease. The world is gaining its interest in treatment through natural sources like foods and medicinal plants. Herbal medicines have already been utilized by various cultures around the world for several therapies including chronic pain, malaria, heart conditions, warts, skin diseases and bowel disorders. The need for functional foods is anticipated to increase as a result of three factors: changing laws, increased health care expenses, and scientific discoveries. Mint is a member of the Lamiaceae family. Mint is an excellent source of vitamins, minerals, phenolic compounds, dietary fiber and antioxidants. Mint is a mysterious herb because of its many unknown aspects through which it promotes good health that should be revealed. Mint is a rich source of Iron. Alkaloids, steroids, and tannins are among phytoconstituents found in mint essential oils that prevent the absorption of sugars and flavonoids.

Exogenous β-Aminobutyric Acid (BABA) Improves the Growth, Essential Oil Content, and Composition of Grapefruit Mint (Mentha suaveolens × piperita) under Water Deficit Stress Conditions

Grapefruit mint, Mentha suaveolens × M. piperita, belonging to the Lamiaceae family, is an important medicinal plant with applications in the cosmetic, pharmaceutical, food, and nutraceutical industries. Environmental factors such as cold, salinity, and water deficit significantly impact the quantity and quality of the active compounds of medicinal plants. To examine the effects of drought stress and β-aminobutyric acid (BABA) as an elicitor on the biochemical characteristics and essential oil (EO) profile of grapefruit mint, a factorial experiment was conducted in a completely randomized design (CRD) with two factor and three replications under greenhouse conditions. The first factor included field moisture capacity (FC) as the control (100% FC), mild (75% FC), moderate (55% FC), and severe water deficit stress (35% FC), while the second factor consisted of 0 (control plants without BABA), 0.8, 1.6, and 2.4 mM of BABA foliar application. Water stress and BABA application significantly affected the EO content and composition of grapefruit mint. The highest content of EO was observed in mild drought stress and BABA spraying at 1.6 to 2.4 mM, which increased by about 140% compared with the control condition. The EO components were identified using GC-FID and GC-MS analysis. Linalool (33.7–47.3%) and linalool acetate (31.2–52%) were the most abundant compounds. The highest content of linalool acetate was observed in severe drought stress (35% FC) with foliar application of BABA (1.6 mM), which increased by 33.86% compared with the control condition. However, the highest content of linalool was observed under normal irrigation with foliar application of 0.8 to 1.6 mM BABA. Based on the results, severe drought stress reduced the total chlorophyll and carotenoids by 81.76 and 64.6% compared with the control condition, respectively. Water stress and the foliar application of BABA significantly affected the activity of antioxidant enzymes (ascorbate peroxidase, APX; guaiacol peroxides, GPX; and superoxide dismutase, SOD). The application of 1.6 mM BABA significantly increased the activity of antioxidant enzymes under water stress conditions. Finally, our results showed that the application of BABA (mainly at 1.6 mM) can improve the grapefruit mint yield and EO profile under water stress conditions.

Anti-Candida and Antibiofilm Activity of Selected Lamiaceae Essential Oils.

Candidiasis is a common oral and vaginal infection. Some papers have presented that the essential oils of Lamiaceae plants can have antifungal activity. This study aimed to investigate the activity of 7 essential oils of the Lamiaceae family with known phytochemical compositions against Candida fungi. Forty-four strains belonging to six species were tested: C. albicans, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis. During this investigation, the following methods were used: determination of the minimal inhibitory concentrations (MICs), biofilm inhibition studies, and in silicotoxicity tests. Essential oils of lemon balm (Melissa officinalis) and oregano (Origanum vulgare) showed the best anti-Candida activity, with MIC values below 3.125 mg/mL. Lavender (Lavandula stoechas), mint (Mentha × piperita), rosemary (Rosmarinus officinalis), and thyme (Thymus vulgaris) essential oils were also very active (0.39 to 6.25 or 12.5 mg/mL). Sage (Salvia officinalis) essential oil presented the lowest activity, with MIC values ranging from 3.125 to 100 mg/mL. In an antibiofilm study using MIC values, oregano and thyme essential oils showed the greatest effect, followed by lavender, mint, and rosemary oils. The weakest antibiofilm activity was observed with the lemon balm and sage oils. In silico toxicity research suggests that most of main compounds of Lamiaceae essential oils probably do not exhibit carcinogenicity, mutagenicity, or cytotoxicity. The obtained results showed that Lamiaceae essential oils have anti-Candida and antibiofilm activity. Further research is required to confirm the safety and efficacy of essential oils in the topical treatment of candidiasis.

Formulation of a Wort-Based Beverage with the Addition of Chokeberry (Aronia melanocarpa) Juice and Mint Essential Oil

In Croatia, the production of non-alcoholic wort-based beverages is in its initial stages. The main goal of this research was to produce wort that could be then used in the production of a wort-based beverage with the addition of chokeberry (Aronia melanocarpa) juice. Sensory characteristics and consumer acceptance was also analyzed. Worts were prepared by the standard mashing process, using Munich and pale ale malt. Chokeberry juice was added to the cooled worts. For the purpose of this research, two versions of wort with different concentrations of chokeberry juice (10%, 20%, 30%) were formulated, and all of the beverages were subjected to sensory analysis. Sensory analysis showed that wort with the addition of 30% chokeberry juice was the most accepted. This concentration of chokeberry juice gave the beverage a pleasant taste, but needed some improvement. To address this, mint essential oil was added to the mixture and carbonation using gaseous CO2 was conducted. This beverage received better acceptance when carbonated and mixed with mint essential oil. In addition to the sensory analysis, the polyphenol content of the chosen beverage was also analyzed, along with its nutritional value. Polyphenol content was 2621.47 mg/L and antioxidative activity was 2.28 mmol Trolox/L. The energy value was determined to be 57 kcal. However, in order to optimize the production of this wort-based beverage, further research should be conducted.

Shade-Induced Effects on Essential Oil Yield, Chemical Profiling, and Biological Activity in Some Lamiaceae Plants Cultivated in Serbia

Thyme, mint, and lemon balm were used to determine whether shading conditions could improve the yield, composition, antioxidant, and antimicrobial activity in plant essential oils (EOs) in comparison with non-shaded plants from an open field. The yield of the EOs of non-shaded thyme, mint, and lemon balm, was 3.44, 3.96, and 0.21 mL/100 g, respectively. Plants covered by nets produced different levels of EOs (3.46, 2.20, and 0.45 mL/100 g) after 120 min of hydrodistillation. The main components of the thyme essential oil are thymol (44.2–43.9%), γ-terpinene (18.3–16.8%), and p-cymene (16.5–17.4%). The predominant components of mint essential oil are piperitenone oxide (52.6–64.8%) and 1,8 cineole (25.9–16.3%), while lemon balm essential oil consists of the following main components: geranial (34.0–32.8%); neral (21.3–24.9%); and piperitenone oxide (17.2–16.7%). The EOs from non-shaded thyme and mint plants have the highest antioxidant activity (EC50 value 0.54 mg/mL and 3.03 mg/mL). However, shaded lemon balm showed a stronger antioxidant activity (EC50 3.43 mg/mL) than non-shaded plants (12.85 mg/mL) after 60 min of incubation. The EOs from all plants showed significant effects against Escherichia coli, Proteus vulgaris, Bacillus subtilis, Staphylococcus aureus, and Candida albicans. The most active EOs against most of the isolates originated from Thymus vulgaris L., plants. Adequate cultivation techniques, such as shading for Lamiaceae plants, has positive effects, especially in Melissa officinalis L. Shading can achieve a higher content and components in terms of the specific biological activity (antioxidant and microbial) of EOs.

Comparative efficacy of essential oil nanoemulsions and bioproducts as alternative strategies against root-knot nematode, and its impact on the growth and yield of Capsicum annuum L.

In a study to compare the effectiveness of some essential oil nanoemulsion and bioproducts as an alternative to chemical nematicide in control of root-knot nematode, Meloidogyne incognita parasitizing on chili pepper, Capsicum annuum L. plants, in parallel with the plant growth and yield under two varying conditions; in vitro , greenhouse and plastic house (intended for commercial production). In an in vitro study, basil and mint essential oil nanoemulsions (at a rate of 5%) achieved the best effects on morality reduction percentage (100%) at droplet sizes of 48.10 nm and 97.3 nm, respectively, compared with the non-treated control. In the greenhouse, Basil and Mint essential oil nanoemulsions (at 5%) (82.59% and 81.52%) and at 3% (77.6% and 72.15%), respectively, ranked second on population reduction, with approximately the effect of Bio-arc (at 2.5 g/L) (74.81%), after Nemaphose (92.7%). A similar pattern was found in a plastic house with a noted positive effect on the increase in yield, where Basil and Mint essential oil nanoemulsions (at 5%) achieved 113.42 and 108.23, respectively.