Peppermint Plants Research Articles

Modulation of Phytochemical Pathways and Antioxidant Activity in Peppermint by Salicylic Acid and GR24: A Molecular Approach.

This study uncovers the potential of salicylic acid (SA) and synthetic Strigolactone (GR24) in enhancing menthol biosynthesis and antioxidant defense mechanisms in Mentha piperita L. Our comprehensive analysis, which included a series of controlled experiments and data analysis of the effects of these phytohormones on enzymatic antioxidants catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidants, including carotenoids and proline, revealed promising results. The study also examined their impact on lipid peroxidation, hydrogen peroxide levels, and the expression of genes critical to menthol and menthofuran synthesis. The results indicated that SA and GR24 significantly increased menthol production and reduced the levels of menthofuran and pulegone, suggesting upregulation in the plant's innate defense systems. Furthermore, the activities of CAT and APX were elevated, reflecting a strengthened antioxidant response. Interestingly, the menthofuran synthase (MFS) was higher in the control group. At the same time, pulegone reductase (PR) genes and menthol dehydrogenase (MDH) gene expression were upregulated, highlighting the protective effects of SA and GR24. These findings underscore the potential of SA and GR24 to serve as effective bio-stimulants, improving the quality and resilience of peppermint plants and thereby contributing to eco-friendly agricultural practices in pollution-stressed environments.

Kebun Pintar dalam Ruang Berbasis Internet of Things

The concept of smart farming emerged as a sign that technology developments in the agricultural sector are growing rapidly. Home gardening activities have become a trend during the pandemic and are often still done manually. This research aims to create a prototype of an indoor smart garden that is connected via the Blynk application to control and display sensor readings. The plant used as a test was a peppermint plant with a testing period of 4 weeks with 2 different treatments. Based on the results of the overall system testing that has been carried out, the monitoring and control system can work well. The soil moisture sensor is prone to corrosion, so it needs to be replaced every 6-7 days. Peppermint plants, in the second test which were given a set point of soil moisture of 60% and provided light for 23 hours, experienced an increase in plant height, the color of the leaves is green and number of leaves increases when compared to the first test which was given a set point of soil moisture of 50% and provided light for 9 hours.

The ameliorating effects of cinnamic acid-based nanocomposite against salt stress in peppermint.

Nanoparticles (NPs) are important in regulating plant tolerance to salt stress. Peppermint is one of the most widely used aromatic plants, with a high sensitivity to salt stress. The present study investigated physiological and biochemical factors to understand better the behavior of cinnamic acid (CA) and cinnamic acid nanocomposite in salinity control in peppermint plants. The first factor was salt stress with different salt concentrations, including 0, 50, 100, and 150 mg/L, the second factor was 50 μM CA, and the third factor was 50 μM CA nanocomposite based on carboxymethyl cellulose (CMC-CA NC). Results showed that stress markers increased with increasing salinity levels. On the contrary, plants treated with salinity showed a decrease in physiological and photosynthetic parameters, while the application of CA and CMC CA NC increased these critical parameters. Under salinity, compared to the control, malondialdehyde and hydrogen peroxide contents decreased by 11.3% and 70.4%, respectively. Furthermore, CA and CMC-CA NC enhanced peppermint tolerance to salinity by increasing compatible solute content such as proline, free amino acids, protein content, and soluble carbohydrates, increasing antioxidant enzymes, and decreasing stress markers in plant tissues. Compared to the control, chlorophyll fluorescence and proline content increased by 1.1% and 172.1%, respectively. Salinity stress negatively affected all physiological and biochemical parameters, but CA and CMC-CA NC treatments improved them. We concluded that the nanocomposite, a biostimulant, significantly enhances mint tolerance under salinity conditions.

Studying the impact of titanium dioxide nanoparticles on the expression of pivotal genes related to menthol biosynthesis and certain biochemical parameters in peppermint plants (Mentha Piperita L.)

BackgroundThis study examines the impact of titanium dioxide nanoparticles (TiO2NPs) on gene expression associated with menthol biosynthesis and selected biochemical parameters in peppermint plants (Mentha piperita L.). Menthol, the active ingredient in peppermint, is synthesized through various pathways involving key genes like geranyl diphosphate synthase, menthone reductase, and menthofuran synthase. Seedlings were treated with different concentrations of TiO2NPs (50, 100, 200, and 300 ppm) via foliar spray. After three weeks of treatment, leaf samples were gathered and kept at -70 °C for analysis.ResultsAccording to our findings, there was a significant elevation (P ≤ 0.05) in proline content at concentrations of 200 and 300 ppm in comparison with the control. Specifically, the highest proline level was registered at 200 ppm, reaching 259.64 ± 33.33 µg/g FW. Additionally, hydrogen peroxide and malondialdehyde content exhibited a decreasing trend following nanoparticle treatments. Catalase activity was notably affected by varying TiO2NP concentrations, with a significant decrease observed at 200 and 300 ppm compared to the control (P ≤ 0.05). Conversely, at 100 ppm, catalase activity significantly increased (11.035 ± 1.12 units/mg of protein/min). Guaiacol peroxidase activity decreased across all nanoparticle concentrations. Furthermore, RT-qPCR analysis indicated increased expression of the studied genes at 300 ppm concentration.ConclusionsHence, it can be inferred that at the transcript level, this nanoparticle exhibited efficacy in influencing the biosynthetic pathway of menthol.Graphical

First record of the glasshouse leafhopper, Hauptidia maroccana (Melichar, 1907) (Hemiptera: Cicadellidae), from Jordan

AbstractThe glasshouse leafhopper, Hauptidia maroccana (Melichar, 1907), is recorded for the first time in Jordan. It was found infesting basil, tomato, pepper, peppermint, celery and parsley plants in ‘Ammān in October 2023. Adult genitalia slide mounts were prepared and voucher specimens were preserved at the University of Jordan Insects Museum. Original images for nymph, adult male and female genitalia, and distribution data, are provided.

Accumulation of biologically active substances in peppermint varieties

Biologically active substances (BAS) are substances that play an important role in the life of organisms. They are involved in various processes, such as metabolism, regulation of growth and development, homeostasis maintenance. We can get natural biological substances from various plants. Such BAS include essential oils, which are essential in the relationship of plants with the environment. The accumulation of essential oils is influenced, among other things, by plant life expectancy. The article considers the dynamics of the accumulation of essential oils and individual components of a perennial peppermint plant by the years of crop cultivation.

Phosphorus Nanoparticles Foliar Application as an Effective Strategy for Improving the Vegetative Growth, Biochemical Traits, and Essential Oil of Peppermint Plants

Phosphorus Nanoparticles Foliar Application as an Effective Strategy for Improving the Vegetative Growth, Biochemical Traits, and Essential Oil of Peppermint Plants

Unraveling the influence of TiO2 nanoparticles on growth, physiological and phytochemical characteristics of Mentha piperita L. in cadmium-contaminated soil

Among the metals contaminants, cadmium (Cd) is one of the most toxic elements in cultivated soils, causing loss of yield and productivity in plants. Recently, nanomaterials have been shown to mitigate the negative consequences of environmental stresses in different plants. However, little is known about foliar application of titanium dioxide nanoparticles (TiO2 NPs) to alleviate Cd stress in medicinal plants, and their dual interactions on essential oil production. The objective of this study was to investigate the effects of foliar-applied TiO2 NPs on growth, Cd uptake, chlorophyll fluorescence, photosynthetic pigments, malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, total phenols, anthocyanins, flavonoids, antioxidant enzymes (SOD, CAT and POD) activity and essential oil content of Mentha piperita L. (peppermint) under Cd stress. For this purpose, plants were grown in Cd-contaminated (0, 20, 40, and 60 mg L−1) soil, and different concentrations of TiO2 NPs (0, 75, and 150 mg L−1) were foliar sprayed at three times after full establishment until the beginning of flowering. Exposure to TiO2 NPs significantly (P < 0.01) increased shoot dry weight (37.8%) and the number of lateral branches (59.4%) and decreased Cd uptake in plant tissues as compared to the control. Application of TiO2 NPs increased the content of plastid pigments, and the ratio Fv/Fm (13.4%) as compared to the control. Additionally, TiO2 NPs reduced the stress markers, MDA and H2O2 contents and enhanced the activity of the phenylalanine ammonia-lyase (PAL) enzyme (60.5%), total phenols (56.1%), anthocyanins (42.6%), flavonoids (25.5%), and essential oil content (52.3%) in Cd-stressed peppermint compared to the control. The results also demonstrated that foliar spray of TiO2 NPs effectively improved the growth and chlorophyll fluorescence parameters and reduced Cd accumulation in peppermint, which was mainly attributed to the reduction of oxidative burst and enhancement of the enzymatic (SOD, CAT, and POD) antioxidant defense system due to the uptake of NPs. The findings provide insights into the regulatory mechanism of TiO2 NPs on peppermint plants growth, physiology and secondary metabolites production in Cd-contaminated soil.

Potential application of light emitting diodes to improve molecular, physiological, and growth responses in peppermint plant

AbstractBackgroundClimate change and growing global population are driving forces that shift the agriculture from open fields to environmentally‐controlled confined systems. In such confined systems, plants are adapted to unique light spectra to achieve maximal qualitative and quantitative yields. In the present study, effects of five light spectra on morpho‐physiological and molecular attributes of peppermint were examined. Treatments included a traditional greenhouse considered as the control, a fluorescent light, and four types of light emitting diodes (LED): red, blue, red‐blue (70:30), and white. Leaf samples were collected from plants and analyzed for volatile constituents using a headspace GC–MS. Meanwhile, changes in the expression profile of genes involved in the biosynthesis of menthol were evaluated.ResultsOur results showed that maximal yield (wet and dry biomass) was achieved under greenhouse condition and the red‐blue LED. Application of the red‐blue LED resulted in maximal production of beneficial monoterpenes, which indicate superiority to greenhouse environment. A significant change in the gene expression profile was observed among plants grown under different light treatments. The red‐blue LED was associated with a significant up‐regulation of key genes in the menthol biosynthesis (menthol dehydrogenase and pulegone reductase). This phenomenon was consistent with a higher menthol production under the same condition.ConclusionThe application of red‐blue LED was associated with the highest level of yield and menthol production, whereas it resulted in lower concentrations of unfavorable by‐products (isomenthol, cis‐pulegone, and menthofuran). In conclusion, 70:30 red‐blue LED can be satisfactory applied to maximize growth yield and optimize favorable bioactive constituent in peppermint.

Exogenous melatonin differentially affects biomass, total carbohydrates, and essential oil production in peppermint upon simultaneous exposure to chitosan-coated Fe3O4 NPs

Melatonin and iron play important roles in the growth processes and production of secondary metabolites in medicinal plants. To evaluate the effects of melatonin and Chitosan-Coated Iron Oxide Nanoparticles (Fe-CTs NPs) on peppermint growth, essential oil content and constituents, total carbohydrates and antioxidant enzyme activities, a factorial experiment was conducted based on randomized complete block design (CRBD) with three replications (n = 3). Treatments consisted of different concentrations of melatonin (0, 100, and 200 mg L−1) and Fe-CTs NPs (0, 7.5, and 15 mg L−1). During the experiment, foliar applications of melatonin and Fe-CTs NPs were performed three times with 20 days’ interval. Treatments with melatonin, and Fe-CTs NPs had significant effects on the studied traits. The results showed that with increasing melatonin and Fe-CTs NPs concentrations, fresh and dry weights, total carbohydrates, and leaf area index were significantly (P < 0.05) increased in treated plants. The highest CAT and APX activities were observed in plants treated with melatonin at 100 mg L−1 and Fe-CTs NPs at 15 mg L−1. Eucalyptol, Menthyl acetate, Thiophene, 2-ethyl-5-(2-methylpropyl), Mint furanone, and Viridiflorol were found as the major essential oil constituents in peppermint plants under experimental treatments. Moreover, analytical results showed that the highest amount of Menthol (38.48 %) was obtained in plants exposed to Fe-CTs NPs at 7.5 mg L−1, however, the highest L-Menthone (30.53 %) was observed in plants treated with melatonin at 200 mg L−1 and Fe-CTs NPs at 15 mg L−1. The findings provide insights into the regulatory mechanisms of melatonin and Fe-CTs NPs on peppermint growth, physiology and biosynthesis of volatile compounds.

First Report of Puccinia menthae Causing Leaf Rust on Peppermint (Mentha x piperita) in Mexico.

Peppermint (Lamiaceae) is an aromatic herb with culinary, medicinal, and industrial properties. In June 2022, symptoms and signs of foliar rust were observed in four commercial fields of peppermint (Mentha × piperita) in San Buenaventura Tecalzingo, San Martín Texmelucan, Puebla, Mexico (19°14'34.0"N 98°27'25.4"W; 19°14'16.7"N 98°27'21.4"W; 19°14'37.0"N 98°27'07.7"W; 19°15'00.6"N 98°26'54.7"W). Two diseased plants were collected at each site. The disease was present in 50% of the plants and the damaged foliar tissue was under 17%. Initial symptoms included small chlorotic spots on the adaxial surface of the leaves, which later spread to form a necrotic area surrounded by a broad chlorotic halo. Necrosis developed only in the presence of abundant reddish-brown pustules on the abaxial surface of the leaf, while smaller pustules were observed on the adaxial surface. The signs were detected as numerous reddish-brown pustules on the abaxial surface of the leaves. The infected leaves of all samples showed subepidermal uredinia, erumpent, with hyaline and cylindrical paraphyses. Urediniospores (n = 50) were hyaline to light brown, echinulate, with two germinative pores, obovoid (16.5-26.5 × 11.5-25.5 μm, mean ± SD = 22 ± 1.6 × 19 ± 0.4 μm and 0.6 μm of wall thickness), individually supported on pedicels. Morphological characteristics aligned most closely with the description of Puccinia menthae by Kabaktepe et al. (2017) and Solano-Báez et al. (2022). A voucher specimen was deposited in the Herbarium of the Department of Plant-Insect Interactions at the Biotic Products Development Center of the National Polytechnic Institute under accession no. IPN 10.0115. From one sample, genomic DNA was extracted, and the 28S gene region of rDNA was amplified by a nested PCR using the primer sets Rust2inv (Aime, 2006) and LR6 (Vilgalys and Hester, 1990), and Rust28SF (Aime et al., 2018), and LR5 (Vilgalys and Hester, 1990) for the first and second reactions, respectively. The obtained sequence (GenBank accession No. OQ552847) showed 100% homology (902/1304bp) with the type-specimen sequence of P. menthae (DQ354513) from Cunila origanoides from USA (Aime, 2006). A phylogenetic analysis using Maximum Likelihood including a published 28S dataset for Puccinia species was executed and the isolate IPN 10.0115 was grouped into a clade of P. menthae with bootstrap support value of 100%. Pathogenicity was assessed by spraying a suspension of urediniospores (1×104 spores/ml) of the isolate IPN 10.0115 onto six healthy peppermint plants (Mentha × piperita) that were 30 days old, while six other plants were sprayed with sterile distilled water. All plants were kept in a wet chamber for 48 h at temperatures from 28±2°C and relative humidity of 95%, after which the plastic bag was removed. All inoculated plants developed disease symptoms after 15 days, whereas the control plants remained symptomless. The pathogenicity assay was conducted twice with similar results. The morphology of the pathogen recovered from the pustules of the inoculated plants was identical to that originally recollected, thus fulfilling Koch'postulates. To our knowledge, this is the first report of Puccinia menthae causing leaf rust on Mentha × piperita in Mexico. This species has been previously identified using morphological characteristics in Brazil, Canada, Poland, and USA on Mentha × piperita (Farr and Rossman, 2023). Since the disease defoliates peppermint plants reducing yield, further information on disease management is needed.

Effects of Ulva intestinalis Linnaeus seaweed liquid extract on plant growth, photosynthetic performance and water status of two hydroponically grown Lamiaceae species: Peppermint (Mentha × piperita L.) and purple basil (Ocimum basilicum var. purpurascens Benth.)

Seaweed extracts are considered as marine biostimulants and have been successfully used in agriculture to improve the growth and tolerance to different environmental stress conditions of many crops. Therefore, the present study was carried out for the first time and aimed to determine the effects of a seaweed liquid extract on growth and photosynthetic performance as well as the water status of hydroponically-grown peppermint and purple basil plants. For this purpose, the experiment was conducted under greenhouse conditions and plants were cultivated in hydroponic systems according to the nutrient film technique. A seaweed liquid extract at 10% was prepared from the green marine macroalgae Ulva intestinalis and then added to the nutrient solution of the hydroponic system. Based on our experimental data, the main results have proven that Ulva intestinalis seaweed liquid extract could be successfully used as a biostimulant in the hydroponic cultivation of peppermint for its enhancing effect on some plant growth and photosynthetic as well as water status parameters. However, it is not recommended to add the seaweed liquid extract of Ulva intestinalis to the hydroponic culture of purple basil since most of the parameters analyzed were shown to be negatively affected by the seaweed liquid extract treatment. Furthermore, the results of this study could be practical for enhancing the production of medicinal and aromatic plants by adding the Ulva intestinalis seaweed liquid extract to the nutrient solution of the hydroponic system.

Simulated dormant peppermint (Mentha × piperita) response to mesotrione: a greenhouse study

AbstractA dose-response trial was conducted in two experimental runs at the Purdue University Horticulture Greenhouses, West Lafayette, IN, in 2021/2022 to determine the effect of mesotrione rate on simulated dormant ‘Redefined Murray Mitcham’ peppermint. Peppermint was established in 20-cm-diam polyethylene pots, it was then harvested, and pots were placed in a cooler (4 C) for 1 mo. Potted peppermint plants were removed from cold storage and treated with one of five mesotrione rates: 0 (nontreated control), 53, 105, 210, or 420 g ai ha–1. As mesotrione rate increased from 53 to 420 g ai ha–1, predicted peppermint injury increased from 35% to 80% at 2 wk after treatment (WAT), 36% to 95% at 4 WAT, 9% to 82% at 6 WAT, and 8% to 90% at 8 WAT; and peppermint height decreased from 74% to 42% of the nontreated control (7 cm) 2 WAT, 74% to 17% of the nontreated control (20 cm) 4 WAT, 81% to 15% of the nontreated control (28 cm) 6 WAT, and 88% to 19% of the nontreated control (37 cm) 8 WAT. Mesotrione rates from 53 to 420 g ai ha–1 reduced peppermint dry weight from 40% to 99%, respectively. Results from this experiment showed that mesotrione applied even at half of the recommended field use rate for corn (53 g ai ha–1) was not safe for peppermint due to a reduction in aboveground biomass.

First Report of Leaf Blight Caused by Colletotrichum karsti on Peppermint (Mentha x piperitavar. citrata) in Mexico.

Spearmint (Mentha x piperita var. citrata (Ehrh.) Briq.: Lamiaceae) is an aromatic herb widely cultivated owing to its industrial properties. In June 2020, symptoms of leaf blight were observed on 1,500 peppermint plants in a commercial nursery located in Cuautla (18°52'18"N 98°57'58"W), Morelos, Mexico. The incidence of the disease was 89%. Symptoms were initially observed as irregular, small black necrotic spots, that grew rapidly until the leaves were blighted. Fungal isolation was done using diseased leaf tissue on potato dextrose agar (PDA) as described by Ayvar-Serna et al. (2020) and Colletotrichum-like colonies were obtained. Six isolates were purified by single spore culture and only a single morphotype was obtained. One isolate was used for pathogenicity tests, morphological characterization, and multilocus phylogenetic analysis. The isolate (accession no. UACH449) was deposited in the Culture Collection of Phytopathogenic Fungi of the Department of Agricultural Parasitology at the Chapingo Autonomous University. Colonies in PDA grow at a rate of 7.0-10.0 mm/d. After 14 days, the colony was white to orange, and conidia (n =100) were hyaline, cylindrical, and straight with rounded ends, measuring 15.0-17.0 × 4.5-6.5 μm. Appressoria were brown and bullet-shaped. In 28-day-old colonies, the formation of perithecia was observed. Asci were hyaline, unitunicate, 8-spored, fasciculate, and cylindrical to clavate. Ascospores (n =100) were hyaline, unicellular, allantoid, inaequilateral, often straight on the inner side, apices rounded, arranged biseriately within the asci, and measured 14-19 × 4.0-7.5 μm. Morphological features of the isolate placed it tentatively within the Colletotrichm boninense species complex (Damm et al. 2012). For molecular identification, genomic DNA was extracted, and the internal transcribed spacer (ITS) region (White et al. 1990), partial sequences of calmodulin (CAL), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and actin (ACT) (Damm et al. 2012) genes were amplified and sequenced. A phylogenetic tree including published ITS, CAL, GAPDH, and ACT data for Colletotrichum species was constructed and the isolate UACH449 was grouped in the clade of Colletotrichum karsti. Sequences were deposited in GenBank under the accession numbers: ITS, OL825605; CAL, OL855890; GAPDH, OL855891 and ACT, OL855889. Pathogenicity was tested by spraying a suspension of 1 × 10^5 conidia/ml, onto eight healthy peppermint plants 30-days-old var. citrata, while eight control plants were sprayed using sterile distilled water. All plants were kept at 25 +/- 2°C and 70% RH. The characteristic symptoms of the disease were observed seven days after inoculation, while control plants remained symptomless. The pathogenicity test was repeated twice. The fungus was consistently reisolated from the eight inoculated plants and was morphologically identical to that originally isolated from diseased leaves, fulfilling Koch's postulates. To date, this pathogen has not been reported on peppermint (Farr and Rossman, 2022). To our knowledge, this is the first report of Colletotrichum karsti causing foliar blight on peppermint worldwide. According to our field observations, this disease is a threat to the production of peppermint plants.

LITERATUR REVIEW: PEMBERIAN PEGAGAN (CENTELLA ASIATICA) SEBAGAI MINUMAN ALTERNATIF UNTUK MENURUKAN TEKANAN DARAH PADA LANSIA

Hypertension usually occurs in people of middle age and above. Causes there are several such things as, changes in the structure of blood vessels, narrowing the lumen, blood vessel becoming stiffer and reduced elasticity. As a result, the risk of developing hypertension increases with age. Treatment of hypertension involves the use of medications and changes in lifestyle habits. Medications for hypertensive patients can be both pharmaceutical and non-pharmacological. The medicinal plant has the ability to reduce high blood pressure by reducing triglyceride levels in the blood, making it a non-pharmacological treatment choice for hypertension. An alternative to non-pharmacological treatment for those with hypertension is the traditional medicine made from the peppermint plant. The method used in this study is literature review. Writing is done through article search by entering keywords in Google Schoolar, Science Direcct, PubMed, and Elsevier. The keywords used in the search are Pegagan, Centella asiatica, blood pressure, Hypertension. In 5 journals results mentioned leaves of peppermint can lower blood pressure. Where the shape of the preparation of pegagan leaves varies, that is, in the form of rebusan, juice, tea or a mixture of tea leaves pegagan with other herbs.

Implementation of Temperature and Humidity Control Devices in IOT-Based Hydrophonic Peppermint Cultivation at Sufiagrifarm Slawi

Along with the rapid development of existing technology, especially in the field of information and the Internet of Thinks ( IoT ), which is developing so fast and producing a lot of benefits to help humans both in the field of education and in manufacturing and agriculture. But at this time there are still so many technologies that still cannot be implemented in certain fields, for example like agriculture, where everything is still done manually so that it takes a lot of time, costs and also more energy in the process. Such as the constraints that exist with Sufiagrifarm, where in this case to meet the needs of temperature and humidity in Peppermint plants that use a hydrophonic planting system it is still done manually by spraying the plants with a spray that produces dew. Given these problems, this research aims to assist Sufiagrifarm in overcoming problems in regulating temperature and humidity in peppermint plants so that temperature and humidity compliance in peppermint plants can be carried out automatically and can be monitored in real time. Development in this method is carried out using the SDLC Waterfall method. This application was created using the Java programming language using the MITApp inventor platform, for the tool itself it was made using an Arduino microcontroller with the C programming language supported by several other devices such as Thingspeak. The results of this study are to help fulfill temperature and humidity in peppermint cultivation at Sufiagrifarm.

Characterization of Peppermint Plant Extract and Antimicrobial Activity

The use of plant extracts in the medical and pharmacological fields have been increased in the last years. The plants have shown to possess materials with important features that can be used as a treatment in multiple health risks such as inflammation, cardiovascular disorders, bacteria and fungus. Peppermint was used extensively as medical herbs and have given a remarkable results. We aimed to prepare water and alcoholic (methanol) extract of peppermint leaves and characterize the presence of some phytochemical compounds qualitatively, along with some trace elements (copper, zinc and selenium). The antimicrobial activity of peppermint extract was investigated against two Gram negative escherichia coli as well as klebsiella sp, also two Gram positive bacterial strains Staphylococcus epidermidis as well as Staphylococcus aureus, as well as one fungi (Candida albicans). We have obtained the presence of flavonoids, polyphenolic compounds, steroids, carbohydrate, and protein contents in the extract of peppermint. Copper, zinc and selenium levels were detected in good amount in the extract. Furthermore, both water and methanol extract of peppermint have shown good antimicrobial activity against the experimented strains. Nevertheless, the extraction by methanol have shown more powerful activity than water against all strains.

Effect of nitrogen fertilizer and salicylic acid spraying on growth and volatile oil content of peppermint (Mentha piperita L.)

A field study was carried out at the Agricultural Research Station of the Agriculture College, Al-Muthanna University (located in southern Iraq) , during season growth 2022.The study aims to know the effect of two factors, first one : adding nitrogen at three levels (0, 75 and 150 Kg. N. ha-1 ), second factor : spraying salicylic acid with three different concentrations (0, 100, 200 mg. SA. L-1 ) and their interaction on growth and essential oil yield of peppermint (Mentha piperita L.). Results showed the significantly superiority of nitrogen fertilizer level 150 Kg. N. ha-1 in all studied characteristics : plant height, branches number, leaves number, fresh weight of the shoot , dry weight of the shoot, volatile oil content and volatile oil yield (46.92cm, 16.89 branch plant-1 ,153.7 leaves plant-1 , 17.49 g plant, 2.66 g plant, 1.02% and 271.0 µL plant-1 , respectively. The peppermint plants sprayed with a concentration (200 mg SA. L-1 ) were significantly superior in plant height, branches number, leaves number, shoot fresh and shoot dry weight (42.88cm, 13.52 branch plant-1 ,129.9 leaf plant-1 , 12.97 g plant-1 and 1.98 g plant-1 ), respectively. While plants treated with concentration (100 mg. SA. L-1 ) gave the highest significant values of volatile oil content and yield of volatile oil ( 0.96 % , 291.9 µL plant), respectively. The interaction treatment (150 Kg. N. ha-1 , with 200 mg SA. L-1 ) gave the highest rates for all the studied except yield of essential oil was a highest in treatment (150 Kg. N. ha-1 , with 100 mg SA. L-1 )

Thermodynamic analysis of solar assisted steam distillation system for peppermint oil extraction

AbstractScheffler reflector (10 m2) integrated peppermint oil (PO) extraction distillation system is developed. Optical loss in reflector and thermal loss in solar still, steam line, and condenser are determined. A solar distillation system of peppermint plants is also subjected to thermal energetic and exergetic study. Exergy and optical efficiencies are 27.58% and 52.25%, respectively, with an average irradiance of 970.5 W/m2 and 6 kg of peppermint for 4 h. Thermal efficiency of solar still, steam line, and condenser are 95.90%, 95.68%, and 87.96%, respectively. Efficiency of system and oil yield per unit of energy consumed is 41.98% and 6.24 ml/kWh, respectively, without insulating steam line. System's efficiency is 46.36%, with an improvement of 2.67% in energy gain by insulating the steam line. Thermodynamic analysis of developed solar steam distillation system (SSDS) for PO extraction will help in finding out energy saving potential at various parts of distillation unit and in improving the performance of distillation unit. This research would provide energy conservation opportunities in various parts of PO extraction SSDS. Exergy analysis and detailed investigation of condenser and steam line are also performed. As a result, incorporating solar energy into PO extraction technology improves opportunities for the source of income in rural areas and increases both income and level of food security for farmers.Practical applicationsThis research would provide energy conservation opportunities in various parts of peppermint oil (PO) extraction solar steam distillation system. Exergy analysis and detailed investigation of condenser and steam line are also performed. As a result, incorporating solar energy into PO extraction technology improves opportunities for the source of income in rural areas and increases both income and level of food security for farmers.Novelty StatementMentioned literature includes thermodynamic analysis of oil extraction system available for crops such as rosemary leaves, basil leaves, etc. Thermodynamic analysis of such a system is limited to these crops and applied to other crops like peppermint, eucalyptus, lavender, etc. As these crops possess different chemical properties and have large potential in essential oil market, a comprehensive thermal analysis is needed to identify various thermodynamic parameters to extract peppermint oil (PO) using solar‐assisted steam distillation system. Present work aims to identify energy and power loss due to convection and radiation at different parts of a solar distillation unit. Exergy analysis and detailed investigation of condenser and steam line are also performed. This research would provide energy conservation opportunities in PO extraction solar steam distillation system. Furthermore, the outcomes of present study have been compared with previously published studies.

The Influence of Microwave Treatments on Bioactive Compounds and Antioxidant Capacity of Mentha piperita L.

Microwave extraction is becoming a popular option in many fields, especially for bioactive compounds from medicinal plants. This paper addresses the application of microwaves in the process of extracting bioactive compounds (phenols, flavonoids, chlorophyll) from peppermint with antioxidant capacity in order to highlight the influence of the microwave field on the quality of the final product in comparison with the control samples. The Mentha piperita L. is a rich source of phenols. The total phenol content after applying the MW treatments significant increased and varied between 25.000 ± 1.992 and 391.687 ± 20.537 mg GAE/100 g dw compared to the untreated sample (8.089 ± 2.745 mg GAE/100 g dw). The same trend was also recorded in the case of the flavonoid and pigment content in peppermint leaves following the application of microwave treatments. The obtained results were investigated using chemometric multivariate analysis. The main purpose of our research was to compare the possibilities of total or partial substitution of conventional extraction technologies with the microwave extraction technology, and also to highlight the existing differences in the amount of total phenols and flavonoids extracted from peppermint plants in different processing conditions. Through microwave processing, a significant increase in polyphenolic compounds is obtained.