Classification of Southeast Asian mints (Mentha spp.) based on simple sequence repeat markers.

Mentha is a complex genus encompassing many species as a consequence of their interspecific hybridization and polyploidy. Southeast Asian mints have been poorly distinguished though they are widely used for culinary and medical purposes. In this study, we have analyzed Southeast Asian mints and known varieties as well as a related Lamiaceae species (Nepeta sp.) using simple sequence repeat (SSR) markers and leaf morphology. Two types of mints were clearly distinguished based on their venation pattern and leaf shape index. We developed 12 SSR markers that allowed good amplification in the Mentha and another Lamiaceae species. In the SSR-based phylogram, the Mentha lines could be delimited into groups I-VI. The Southeast Asian mints divided into groups I and II, and the phylogram separated most of the available species, with groups I and II containing the known species M. × cordifolia and M. arvensis, respectively. The separation of the two groups was supported by a population structure analysis. The SSR markers developed in this study enabled the simultaneous classification of mints and will help improve our understanding of the genetic composition of known mint varieties and as yet unclassified Southeast Asian mints.

Headspace Solid-Phase Micro-Extraction Versus Hydrodistillation of Volatile Compounds from Leaves of Cultivated Mentha Taxa: Markers of Safe Chemotypes.

Various mint taxa are widely cultivated and are used not only for medicinal purposes but also in cosmetic and industrial applications. The development of new varieties or cultivars of mint generates difficulties in their correct identification and safe use. Volatile organic compounds (VOCs) from the leaves of seven different taxa of the genus Mentha obtained by hydrodistillation (HD) and headspace solid-phase microextraction (HS-SPME) were analyzed using gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) was also performed. Comparative GC-MS analysis of the obtained extracts showed similarity in the major compounds. PCA data allowed the separation of two groups of chemotypes among the analyzed mints, characterized by the abundance of piperitenone oxide and carvone. Two out of seven analyzed taxa were not previously examined for VOC profile, one was examined only for patent application purposes, and six out of seven were investigated for the first time using the HS-SPME technique. The presented analysis provides new data on the abundance and qualitative characterization of VOCs in the studied mint plants and on the safety of their use, related to the possibility of the presence of potentially toxic components. HS-SPME is a valuable method to extend the characterization of the VOC profile obtained by hydrodistillation.

Mint (Mentha spp.) Honey: Analysis of the Phenolic Profile and Antioxidant Activity.

Research background: The composition of honey is influenced by the botanical source and geographical area of the nectar from which it is derived. Unifloral honeys reach higher market value than multifloral honeys due to their specific aromas, which result from volatile and phenolic compounds. Experimental approach: The aim of our study is to characterize the phenolic composition of a rare unifloral variety of honey - mint (Mentha spp.) honey. For this purpose, we performed standard physicochemical analyses, pollen analysis, determined total phenolic and flavonoid content, analysed antioxidant activity and performed qualitative and quantitative analyses of phenolic compounds for five mint honeys. Results and conclusions: Our results indicate that mint honey samples have high phenolic content, expressed in gallic acid equivalents, from (76.7±0.6) to (90.1±1.1) mg/100 g, and flavonoid content, expressed as quercetin equivalents, from (6.7±0.6) to (12.5±0.8) mg/100 g. These honey samples also exhibit strong antioxidant activity, expressed as Trolox equivalents, from (33.6±2.8) to (51.3±1.2) mg/100 g and from (14.4±0.8) to (55.1±2.4) mg/100 g when analysed with DPPH and ABTS assays, respectively. Quantitative LC-MS/MS analysis revealed that the most abundant phenols in all samples were chrysin, apigenin and p-coumaric acid. Qualitative LC-MS/MS analysis identified the presence of kaempferide, diosmetin, acacetin and several caffeic acid derivatives. Novelty and scientific contribution: Our study indicates that mint honey contains unique phenolic profiles, which likely contribute to its distinctive aroma and strong antioxidant activity. A detailed description of the rare honey varieties gives beekeepers greater visibility and easier access to the demanding natural product market.

Characterization, activities, and ethnobotanical uses of Mentha species in Morocco.

This work is a summary of the characterization, activities, and ethnobotanical surveys about aromatic and medicinal plants belonging to the genus Mentha in Morocco. The Mentha species investigated are Mentha pulegium, Mentha spicata, Mentha viridis, Mentha suaveolens, Mentha longifolia, Mentha gattefossei, Mentha rotundifolia, and Mentha vulgare, with M. pulegium being the most studied species. M. spicata and M. viridis are poorly explored even though they are daily consumed by Moroccans in tea infusions. The elucidated factors affecting the composition of Mentha essential oils are fertilization, drying conditions, mechanical impedance, NaCl stress, and Gamma irradiation. Investigation of the activities of the Mentha species showed that the main interest was dedicated to addressing the antibacterial effect towards gram+ and gram- bacteria. Essential oils of Mentha species exhibited antifungal, antiviral, antioxidant, insecticidal, licidal, niticidal, allelopathic, antidiabetic, derma-protective, and anticorrosive activities. The ethnobotanical surveys revealed that Mentha species are used in seven regions: Tafilalet, High Atlas, Fez-Boulemane, Taounat, Oujda, Ouazzane, and Rabat. By calculating the Jaccard index, the highest degree of similarity was found between Tafilalet, Rabat, and Oujda regions. The wide use of the Mentha species in Morocco highlights the high ethnobotanical value of the genus.

A comparative study of antibacterial and antifungal activities of extracts from four indigenous plants.

A repetitive and wide use of chemical antibiotics has brought a serious threat in the biomedical and clinical sectors by the emergence of multidrug resistant pathogens. Plants have secondary metabolites that make them suitable candidate for natural antimicrobial agent without any side effect. In this study, we assessed comparative antibacterial and antifungal effects of extracts from four Indigenous plants (Nerium sp; Mentha sp; Aloe vera and Eucalyptus sp). Total phenolic and flavonoid content were extracted by microwave-assisted extractor and used for phytochemical assay. Antimicrobial experiment was done by micro dilution technique. A post hoc analysis inbuilt with one-way ANOVA test was used for the compilation of antibiotic sensitivity data and percent inhibition. Total phenolic content was significantly high in Mentha sp. and low in Nerium sp. (All p < 0.05). In antibacterial and antifungal activity higher concentrations of extracts showed a strong activity, which was as good as antibiotics used as control. Results from Eucalyptus sample showed a significant growth reducing capability even at lower concentrations. This study concludes that the plant extracts can be used to treat microbial infections with almost same efficacy as antibiotics and with a lower chance of resistance development.

Antioxidant, Antifungal, Antibiofilm, and Cytotoxic Activities of Mentha spp. Essential Oils.

Since ancient times, plants have been used to preserve food, or for their health properties. Essential oils are complex mixtures of volatile compounds that are obtained from botanical material, specifically from aromatic plants. Lamiaceae is one of the most important families in the production of essential oils, as it has both antioxidant and antimicrobial properties. The essential oils of Mentha (the Lamiaceae family) have been extensively studied for their biological actions. In this review, we report the antioxidant, antifungal, antibiofilm, and cytotoxic properties of Mentha spp. essential oils. The first objective is to provide comprehensive information about the use of essential oils in the treatment of fungal infections, or as antioxidants and integrative anticancer therapy. The second is to explore the evidence supporting its effectiveness in treating diseases without causing any serious adverse reactions.

Investigation of damage to Escherichia coli, Listeria monocytogenes and Salmonella Enteritidis exposed to Mentha arvensis L. and M. piperita L. essential oils in pineapple and mango juice by flow cytometry.

The effects of Mentha arvensis L. (MAEO; 0.625 µL/mL) and M. piperita L. (MPEO; 1.25 µL/mL) essential oils on viable cell counts and physiological functions in Escherichia coli, Listeria monocytogenes and Salmonella enterica Serovar Enteritidis in pineapple and mango juice after a 15 min-exposure under refrigeration were evaluated in this study. The physiological functions of the bacterial cells were assessed by flow cytometry using the fluorochromes thiazole orange, propidium iodide, bis-1,3-dibutylbarbutiric acid, ethidium bromide, and 5-cyano-2,3-ditolyl tetrazolium chloride to investigate membrane integrity, membrane potential, efflux activity, and respiratory activity. MAEO and MPEO sharply reduced (>5 log10 CFU/mL cycles) the counts of E. coli, L. monocytogenes and Salmonella Enteritidis in pineapple juice, and caused smaller reductions (0.61-1.58 log10 CFU/mL cycles) in mango juice. Bacterial cells exposed to MAEO and MPEO in pineapple and mango juice showed increased membrane permeability, membrane depolarization and changes in efflux pump and respiratory activity. More physiological damage occurred in bacterial cell populations exposed to MAEO or MPEO in pineapple juice than in mango juice. These results indicate that MAEO and MPEO inactivate E. coli, L. monocytogenes and Salmonella Enteritidis cells in pineapple and mango juice through a multi-target action mode that disrupts cytoplasmic membranes, increases permeability and potential depolarization, as well as inhibits efflux pump and respiratory activity.

Inactivation of Spoilage Yeasts by Mentha spicata L. and M. × villosa Huds. Essential Oils in Cashew, Guava, Mango, and Pineapple Juices.

This study evaluated the efficacy of the essential oil from Mentha spicata L. (MSEO) and M. × villosa Huds. (MVEO) to inactivate Candida albicans, C. tropicalis, Pichia anomala and Saccharomyces cerevisiae in Sabouraud dextrose broth and cashew, guava, mango, and pineapple juices during 72 h of refrigerated storage. The effects of the incorporation of an anti-yeast effective dose of MSEO on some physicochemical and sensory characteristics of juices were evaluated. The incorporation of 3.75 µL/mL MSEO or 15 µL/mL MVEO caused a ≥5-log reductions in counts of C. albicans, P. anomala, and S. cerevisiae in Sabouraud dextrose broth. In cashew and guava juices, 1.875 µL/mL MSEO or 15 µL/mL MVEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae. In pineapple juice, 3.75 µL/mL MSEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae; 15 µL/mL MVEO caused ≥5-log reductions in counts of S. cerevisiae in mango juice. The incorporation of 1.875 µL/mL MSEO did not affect the physicochemical parameters of juices and did not induce negative impacts to cause their possible sensory rejection. These results show the potential of MSEO and MVEO, primarily MSEO, to comprise strategies to control spoilage yeasts in fruit juices.

Genotoxicity assessment of piperitenone oxide: An in vitro and in silico evaluation.

Piperitenone oxide, a natural flavouring agent also known as rotundifolone, has been studied for the genotoxicity assessment by an integrated in vitro and in silico experimental approach, including the bacterial reverse mutation assay, the micronucleus test, the comet assay and the computational prediction by Toxtree and VEGA tools. Under our experimental conditions, the monoterpene showed to induce both point mutations (i.e. frameshift, base-substitution and/or oxidative damage) and DNA damage (i.e. clastogenic or aneuploidic damage, or single-strand breaks). Computational prediction for piperitenone oxide agreed with the toxicological data, and highlighted the presence of the epoxide function and the α,ß-unsaturated carbonyl as possible structural alerts for DNA damage. However, improving the toxicological libraries for natural occurring compounds is required in order to favour the applicability of in silico models to the toxicological predictions. Further in vivo evaluations are strictly needed in order to evaluate the role of the bioavailability of the substance and the metabolic fate on its genotoxicity profile. To the best of our knowledge, these data represent the first evaluation of the genotoxicity for this flavour compound and suggest the need of further studies to assess the safety of piperitenone oxide as a flavouring agent.

A Comparative Analysis of the Chemical Composition, Anti-Inflammatory, and Antinociceptive Effects of the Essential Oils from Three Species of Mentha Cultivated in Romania.

This work was aimed at correlating the chemotype of three Mentha species cultivated in Romania with an in vivo study of the anti-inflammatory and antinociceptive effects of essential oils. The selected species were Mentha piperita L. var. pallescens (white peppermint), Mentha spicata L. subsp. crispata (spearmint), and Mentha suaveolens Ehrh. (pineapple mint). Qualitative and quantitative analysis of the essential oils isolated from the selected Mentha species was performed by gas chromatography coupled with mass spectrometry (GC-MS). The anti-inflammatory activity of the essential oils was determined by the rat paw edema test induced by λ-carrageenan. The antinociceptive effect of the essential oils was evaluated by the writhing test in mice, using 1% (v/v) acetic acid solution administered intraperitonealy and by the hot plate test in mice. The results showed a menthol chemotype for M. piperita pallescens, a carvone chemotype for M. spicata, and a piperitenone oxide chemotype for M. suaveolens. The essential oil from M. spicata L. (EOMSP) produced statistically significant and dose-dependent anti-inflammatory and antinociceptive effects.

Purified bioactive compounds from Mentha spp. oils as a source of Candidosis treatment: A brief review / Compostos bioativos purificados de óleos de Mentha spp. como fonte de tratamento de candidose: Uma breve revisão

Medicinal plants have been the subject of many studies in an attempt to discovery alternative drugs, since they are sources of potentially bioactive compounds that may act in the maintenance of human health. The discovery of new antimicrobial substances or biocomponents derived from natural products has been important in the control of microorganisms, especially due to the increase of cases of resistance to conventional antimicrobials. In parallel, yeasts of the genus Candida are becoming a public health problem in the last decades due to the increase of infections denominated candidosis. Candida spp. has mechanisms of virulence, such as polymorphism and biofilm formation, that facilitate the development of the infection and difficult the treatment. In this sense, studies found in the literature with bioactive compounds from Mentha spp. essential oil, describe their antifungal action, especially from the isolated compounds as carvone, mentone, menthofuran and pulegone. In this sense, this review describes studies about antimicrobial activity of these compounds especially against yeasts of Candida species and some particularities of this genus such as virulence mechanisms once these themes are crucial for the development of new alternative drugs and/or antifungal agents that may act as adjuncts to conventional treatments against these microorganisms.(AU)

Plantas medicinais têm sido objeto de muitos estudos na tentativa de descobrir drogas alternativas, uma vez que são fontes de compostos potencialmente bioativos que podem atuar na manutenção da saúde humana. A descoberta de novas substâncias antimicrobianas ou biocomponentes derivadas de produtos naturais tem sido importante no controle de microrganismos, especialmente devido ao aumento de casos de resistência a antimicrobianos convencionais. Em paralelo, leveduras do gênero Candida vem se tornando um problema de saúde pública nas últimas décadas, devido ao aumento de infecções denominadas candidoses. Candida spp. possuem mecanismos de virulência, como polimorfismo e formação de biofilme, que facilitam o desenvolvimento da infecção e dificultam o tratamento. Nesse sentido, estudos na literatura com compostos bioativos do óleo essencial de Mentha spp. descrevem sua ação antifúngica, especialmente dos compostos isolados como carvona, mentona, mentofurano e pulegona. Sendo assim, esta revisão teve como objetivo abordar estudos sobre a atividade antimicrobiana destes compostos especialmente contra leveduras do gênero Candida e algumas particularidades desse gênero, tais como mecanismos de virulência, uma vez que esses temas se tornam cruciais para o desenvolvimento de novas drogas alternativas e/ou agentes antifúngicos que possam atuar como adjuvantes aos tratamentos convencionais contra esses microrganismos.(AU)

The efficacy of Mentha arvensis L. and M. piperita L. essential oils in reducing pathogenic bacteria and maintaining quality characteristics in cashew, guava, mango, and pineapple juices.

This study evaluated the ability of the essential oil from Mentha arvensis L. (MAEO) and M. piperita L. (MPEO) to induce ≥5-log reductions in counts (CFU/mL) of E. coli, L. monocytogenes, and Salmonella enterica serovar Enteritidis in Brain-Heart Infusion broth (BHIB) and cashew, guava, mango, and pineapple juices during refrigerated storage (4±0.5°C). The effects of the incorporation of these essential oils on some physicochemical and sensory parameters of juices were also evaluated. The incorporation of 5, 2.5, 1.25, or 0.625µL/mL of MAEO in BHIB caused a ≥5-log reduction in counts of E. coli and Salmonella Enteritidis after 24h of storage; but only 5µL/mL was able to cause the same reduction in counts of L.monocytogenes. The incorporation of 10µL/mL of MPEO in BHIB caused a ≥5-log reduction in counts of E. coli, Salmonella Enteritidis, and L. monocytogenes after 24h of storage; smaller reductions were observed in BHIB containing 5, 2.5, and 1.25µL/mL of MPEO. Similar reductions were observed when the MAEO or MPEO was incorporated at the same concentrations in mango juice. The incorporation of MAEO or MPEO at all tested concentrations in cashew, guava, and pineapple juices resulted in a ≥5-log reduction in pathogen counts within 1h. The incorporation of MAEO and MPEO (0.625 and 1.25µL/mL, respectively) in fruit juices did not induce alterations in °Brix, pH, and acidity, but negatively affected the taste, aftertaste, and overall acceptance. The use of MAEO or MPEO at low concentrations could constitute an interesting tool to achieve the required 5-log reduction of pathogenic bacteria in cashew, guava, mango, and pineapple fruit juices. However, new methods combining the use of MAEO or MPEO with other technologies are necessary to reduce their negative impacts on specific sensory properties of these juices.

Identification and quantification of phenolics in Australian native mint (Mentha australis R. Br.).

Australian native mints have traditionally been used by the aboriginal people for natural remedies; however, their bioactive components have not been studied. Antioxidant capacity and composition of phenolic compounds of Mentha australis R. Br., Lamiaceae were investigated for the first time. Phenolic compounds were analyzed by HPLC photodiode array detector, liquid chromatography high resolution mass spectrometry, tandem mass spectrometry and nuclear magnetic resonance spectroscopy. Aqueous methanolic extract of the mint exhibited comparable antioxidant capacity to the common spearmint. Major compounds identified in the extract were rosmarinic acid (160.4 ± 0.85 µg mg(-1)purified extract), neoponcirin (145.0 ± 0.42 µg gallic acid equivalent(GAE) mg(-1)), narirutin (30.3 ± 0.02 µg GAE mg(-1)), chlorogenic acid (15.4 ± 0.05 µg mg(-1)) and biochanin A (9.6 ± 0.06 µg GAE mg(-1)), while minor compounds were caffeic acid, apigenin, hesperetin and naringenin. Neoponcirin and biochanin A were identified for the first time in the Mentha genus.

Coatings comprising chitosan and Mentha piperita L. or Mentha × villosa Huds essential oils to prevent common postharvest mold infections and maintain the quality of cherry tomato fruit.

In this study, we evaluated the efficacy of coatings comprising shrimp chitosan (CHI) and Mentha piperita L. (MPEO) or Mentha × villosa Huds (MVEO) essential oils to control mold infections caused by Aspergillus niger, Botrytis cinerea, Penicillium expansum and Rhizopus stolonifer in cherry tomato fruits (Solanum lycopersicum L.) during storage at room temperature (25°C for 12 days) and low temperature (12°C for 24 days). The effects of the coatings on the physicochemical and sensory characteristics of cherry tomato fruits during storage were also assessed. The minimum inhibitory concentration (MIC) of CHI against all test fungi was 8 mg/mL, whereas the MIC for both MPEO and MVEO was 5 µL/mL. Combinations of CHI at 4 mg/mL and MPEO or MVEO at 2.5 or 1.25 µL/mL strongly inhibited the mycelial growth and spore germination of target fungi. The coatings comprising CHI and MPEO or CHI and MVEO at the different tested concentrations delayed the growth of decay-causing fungi in artificially contaminated tomato fruit during storage at either room temperature or low temperature. The assayed coatings preserved the quality of cherry tomato fruit during storage, in terms of physicochemical and sensory attributes. These results indicate that coatings comprising CHI and MPEO or CHI and MVEO represent promising postharvest treatments to prevent common postharvest mold infections in cherry tomato fruit during storage without affecting the quality of the fruit.

Nutritional and sensory quality during refrigerated storage of fresh-cut mints (Mentha×piperita and M. spicata).

The effect of storage time on quality attributes of refrigerated fresh-cut mints (Mentha×piperita and M. spicata) was studied. Atmosphere composition, respiratory activity, weight loss, surface colour, total chlorophyll, carotenoids, browning potential, total phenols, flavonoids, radical-scavenging activity, ascorbic acid and essential oil yield and composition were analysed. Respiratory activity of peppermint and spearmint samples diminished moderately (42% and 28%, respectively) after 21days at 0°C. A slight modification of the internal atmosphere was achieved. Surface colour, chlorophyll, carotenoid and antioxidant compounds remained almost constant. The yield of essential oil did not change or it showed an apparent increase after 21days at 0°C, depending on plant growth stage. The characteristic flavour components of peppermint (menthone and menthol) increased, while the contents of the main constituents of spearmint essential oil showed minor variations after storage. The conditions assayed for packaging and storing fresh-cut mints were adequate to achieve a relatively long shelf life and they retained their antioxidant properties.

Bases farmacológicas e toxicológicas potenciais do óleo essencial de Mentha spp / Potential pharmacological and toxicological basis of the essential oil from Mentha spp

During the past few years, interest in the potential clinical and pharmacological basis of the efficacy and safety of herbal medicines has increased greatly, due to widespread domestic self-medication with these agents. Some authors have analyzed the use of Mentha ssp. in the pharmacological industry. The essential oil from Mentha spp. is used to treat discomfort of the gastrointestinal tract, irritable bowel syndrome, myalgia and neuralgia, as well as oral mucosal inflammation, and also as an expectorant, an antimicrobial and an ingredient in many analgesic creams. The essential oil also contains chemical compounds that are associated with side effects such as nausea, vomiting, allergic reactions, flushing and headaches. Therefore, the purpose of the present review was to examine the literature on the efficacy and safety of the possible clinical and pharmacological uses of the essential oil from Mentha spp. in human beings.

Nas últimas décadas, houve um aumento crescente no interesse sobre as bases clínicas e farmacológicas potenciais em relação à eficácia e a segurança das drogas produzidas de plantas medicinais, devido à automedicação destes agentes. Diversos autores avaliaram o óleo essencial de Mentha spp., devido a sua larga utilização na indústria farmacológica. O óleo essencial de Mentha spp. componente de muitos analgésicos e com atividade antimicrobiana, é usado para tratamentos nos desconfortos gastrintestinais e dutos biliares superiores, Síndrome de Bowel, expectorante, mialgia e neuralgia, bem como na inflamação oral da mucosa. No entanto, esse óleo contém compostos químicos que apresentam efeitos colaterais tais como náusea, vômito, reações alérgicas e dores de cabeça. O objetivo desta revisão atual foi avaliar dados da literatura específica sobre a possível utilização, eficácia e segurança clínica e farmacológica do óleo essencial de Mentha spp. em seres humanos.

Avaliação sazonal do rendimento de óleo essencial em espécies de menta / Seasonal evaluation of essential oil yield of mint species

O gênero Mentha compreende diversas espécies de interesse econômico por causa da produção de óleos essenciais. Recentemente, foram introduzidos no Brasil novos materiais genéticos para avaliação da adaptação em relação ao potencial de rendimento e composição do óleo essencial. No presente trabalho, foram comparadas essas características em cultivares das espécies Mentha x piperita L. (cv. Grapefruit Mint e cv. Persian Mint Field), M. suaveolens Ehrh. (cv. Hillarys Sweet Lemon Mint), M. spicata L. (cv. Mentol Mint), M. aquatica L. (cv. Common Mint) e M. arvensis L. (cv. Banana Mint), durante o verão e inverno em Curitiba (PR). O rendimento médio das cultivares no verão foi aproximadamente o dobro do rendimento observado no inverno. Duas cultivares de Mentha x piperita L. (cv. Persina Mint Field e cv. Grapefruit Mint) apresentaram maior rendimento de óleo essencial no verão e inverno, sendo que as demais não diferiram entre si. A análise da composição do óleo essencial indicou grande variação nessas cultivares, sendo observada a presença de linalol, como constituinte majoritário na cv. Grapefruit Mint e a-felandren-8-ol e cis-ocimeno na cv. Persian Mint Field.

The genus Mentha includes many species of economic interest due the essential oil production. Recently new genetic materials were introduced in Brazil to evaluate the adaptation related to essential oil yield and composition. In the present work, these characteristics were compared in six cultivars of the species Mentha x piperita L. (cv. Grapefruit Mint e cv. Persian Mint Field), M. suaveolens Ehrh (cv. Hillarys Sweet Lemon Mint), M. spicata L. (cv. Mentol Mint), M. aquatica L. (cv. Common Mint) and M. arvensis L. (cv. Banana Mint) during summer and winter in Curitiba (PR). The average of essential oil yield obtained from samples collected during the summer was approximately two fold the observed during the winter. Two cultivars of Mentha piperita (cv. Persian Mint Field and cv Grapefruit Mint) showed great essential oil yield in both seasons, while the others did no show any difference. The analyses of the essential oil composition indicated great variation among the mint cultivars, being observed the presence of linalool as main constituent in cv. Grapefruit mint and a-phellandren-8-ol and cis-ocimene in cv. Persian Mint Field