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Text | Xue Zhengzheng AA
Edit | Xue Zhengzheng AA
introduction
Peppermint essential oil is a common essential oil with many unique ingredients and antibacterial effects. Its main source is extracted from the peppermint plant, and the main components include menthol, menthone and mentholaldehyde.
Menthol is one of the main components in peppermint essential oil, with a strong cooling sensation, it is not only able to stimulate the cold receptors of the skin, making people feel refreshing and comfortable, but also has antibacterial and anti-inflammatory effects, can effectively inhibit the growth of bacteria and fungi, reduce the risk of infection.
Peppermint is a well-known genus in this plant family, growing widely in temperate regions around the world, especially in Europe, Asia, Africa, Australia and North America, plants in the genus Peppermint are significantly bioactive, it has a wide range of morphological variability, and the chemical composition of its essential oils is very diverse.
Antimicrobial activity of peppermint essential oil
One of the most famous is peppermint essential oil, which is widely used in the treatment of respiratory diseases, such as bronchitis, sinusitis, tuberculosis, etc., the chemical composition of peppermint is complex and extremely variable, each species has its own unique main compounds, in addition, the chemical composition of essential oils may change according to life cycle stages, plant organs, geographical location and other factors.
Regarding the properties of the genus Menthol, several have been reported according to studies, antiviral, antibacterial, antifungal, high antioxidant properties, cytotoxicity, anti-inflammatory and anti-allergic.
Society tends to eliminate chemicals used to treat different biological pathogens while causing diseases, and global consumers and food safety agencies have led researchers to prioritize the use of natural alternatives to control these diseases.
As an antimicrobial agent, peppermint contains a variety of volatile odor essential oils, and its complex composition is rich in antibacterial, antiviral and other bioactive molecules, and in the current food industry, fungal contamination is a widespread problem, causing great trouble to the preservation and storage of fruits and vegetables.
The emergence of fungi, which may lead to a decrease in postharvest quality, loss of yield, and increased economic costs, and may even pose a threat to human health, controlling the spread of fungi to prolong the supply chain of fruits and vegetables is essential to ensure food safety and reduce economic losses.
To address this issue, the researchers will focus on exploring the potential of natural antifungal agents to determine their antifungal effects on fungi, and one of the goals of this study is to determine the chemical composition of peppermint essential oil and evaluate the antifungal effects of four important plant pathogenic fungi and postharvest fungi.
By analyzing the composition of peppermint essential oil, the researchers found that there are a variety of molecules with antibacterial, antifungal and antiviral activities that can inhibit fungal growth and reproduction, thereby alleviating the problem of food contamination caused by fungi.
To evaluate the antifungal potential of peppermint essential oil, involving four important plant pathogenic fungi and postharvest fungi, the researchers used different concentrations of peppermint essential oil to determine its inhibitory effect on these fungi, and the results showed that peppermint essential oil has significant antifungal activity, which in turn can effectively inhibit the growth and reproduction of these fungi.
These findings suggest that the use of peppermint essential oil as a natural antifungal agent can extend the storage life of fruits and vegetables, reduce postharvest losses, and provide a safer food supply, which will bring important health benefits to both consumers, but further research is needed to determine the optimal application conditions for peppermint essential oil in different environments.
Experimental materials and methods for peppermint essential oil
The researchers obtained M. M. from plant material collected from experimental fields. Spicata and M. The essential oils of suaveolens, subsequently, the collected two plants were hydrodistilled using a Clevenger-type device and 3 liters of distilled water for 3 hours.
After drying with anhydrous sodium sulfate, the essential oil can be diluted to 2% dichloromethane and stored in glass bottles at -18°C without light until gas chromatography.
According to the analysis, it was performed on a Varian Saturn 2000 equipped with a capillary column, and the same working conditions were used for gas chromatography and split mode injection, mass spectrometry in the range of m/z 28-400, ionization voltage of 70 eV, followed by the use of standard hydrocarbons in cochromatography, the calculation of linear retention index in preparation for the next study.
The next bioassay is performed in Petri dishes and relies on peppermint essential oil. Researchers dissolved in pre-sterilized potato glucose-based flasks at concentrations of 200, 300, and 400 μg/mL at 45-50°C and dispensed into Petri dishes when the medium was still liquid.
To measure colony diameters in both vertical directions to assess fungal growth, Petri dishes are inoculated on PDA medium, grown colony discs for 7 days, and incubated in the dark at 25°C for 7 days, in between, using 5 replicate dishes for each essential oil, dose, and fungus 3 times a day.
The Petri dish in the control group, which contained only PDA/Tween 20 and the fungus to be analyzed, assessed the growth of the hyphae by measuring the diameter of the vertical colony.
The fungal growth results, statistically analyzed by ANOVA, followed by HSD Tukey confidence intervals, compared species and treatments, significantly set at P < 0.05, and analyzed using Statgraphics Centurion XVII software.
Chemical composition of commercial essential oils
The researchers classified the essential oil composition of spearmint, peppermint and basil according to the class of terpene compounds: 63.6%, 92.0% and 77.3% of oxidized monoterpenes, and 25.4%, 4.0% and 7.3% of hydrocarbon monoterpenes. The content of sesquiterpenes was 7.9%, 3.1% and 6.6%, respectively.
The main compounds in menthol are menthol and its derivatives, mentholone, menthyl acetate, menthol furan and neomenthol, while the relatively high content of 1,8-cineoleol, menthol oil in turn usually contains menthol isomers and their esters, as well as derivatives such as menthol as the main compound.
Some of the samples in the study exhibited different chemical combinations, with hydrocarbon monoterpenes, or oxidized monoterpenes being the main components.
The main components of spearmint are anisone and limonene, and there are some significant amounts of oxide monoterpenes, but some components are different from other oxidized monoterpenes, such as 1,8-cineoleol and dihydroanisole.
As for basil, the essential oil used here exhibits two of the most representative balanced combinations of the species: menthone oxide and menthone ketone oxide, and a small amount of other monoterpenes such as limonene or sabidol.
M. suaveolens essential oil has a characteristic combination, mainly characterized by compounds rich in oxymethyl menthol backbone on C3, such as mentholone, menthone ketone, and C2 similar to anisole and dihydroanisole, also rich in oxygen-rich compounds.
At the same time, the researchers also reported other chemical combinations, such as anisol and 1,8-cineoleol, rich in rutone, and monoterpene essential oils such as methanol.
The study resulted in the best antifungal activity results for basil essential oil, up to 400 μg/mL, and a maximum growth inhibition rate of 100% in all the fungi studied.
Although the inhibition rate of some fungi against Fusarium is only 94.21%, the effect is slightly reduced, but the results of the study are still very satisfactory.
When the dose is reduced to 200 μg/mL, the MGI value of basil essential oil is significantly reduced, showing a large difference in the percentage of MGI compared to higher doses, with only Botrytis dwarf exceeding 50%, while Dalf ivy bacteria in peppermint and spearmint showed similar results.
In the post-hoc examination of Tukey HSD, the significance of fungal growth results under the test conditions was shown, but Botrytis dwarf was the fungus with the highest sensitivity to the treatment of these three peppermint essential oils.
By using basil essential oil, the researchers found no significant difference between Botrytella dwarf and Fusarium at doses of 400 μg/mL and 300 μg/mL, which just suggests that the treatment is effective, but there is a significant difference between the two doses for the growth of Dalph ivy bacteria.
Results were obtained for peppermint essential oil on four pathogenic fungi, similar to those for other fungal species, and the study also evaluated the effect of peppermint essential oil on spore germination of Sporendosporus coastalensis, hyphae growth in ex vivo cultures, and different concentrations on papaya fruit.
In the antifungal study of peppermint essential oil, the researchers conducted a series of tests to evaluate its effect on inhibiting fungal growth, and by observing spore germination and ex-vivo cultured hyphae growth, the researchers found that peppermint essential oil showed strong inhibitory effects in both aspects.
When the researchers added peppermint essential oil to the medium in the laboratory in the ex vivo environment, they observed that the germination rate of spores was significantly reduced, and the growth rate of hyphae was also inhibited, indicating that peppermint essential oil can effectively inhibit the growth of fungi in the ex vivo environment.
Subsequently, the researchers also conducted in vivo tests to evaluate the inhibitory effect of peppermint essential oil on fungi, they applied peppermint essential oil to plants infected with pathogenic fungi, and observed the growth of pathogenic bacteria in plant tissues, and the results showed that peppermint essential oil showed a good inhibitory effect on these fungi and could effectively reduce the severity of the disease.
These results highlight the potential of peppermint essential oil as an antifungal agent, which shows good inhibitory effect in the stage of spore germination and hyphae growth, whether in vivo environment or in vivo, it can effectively control the growth of fungi, especially for Flavonosis and other pathogenic fungi, and the inhibitory effect of peppermint essential oil is particularly significant.
Moreover, these findings contribute to an in-depth understanding of the antifungal mechanism of peppermint essential oil, and provide a scientific basis for its application in the agricultural and food industries, which can further explore the antifungal components of peppermint essential oil, optimize the use method, and evaluate its combined effect with other antifungal agents to achieve a wider range of applications.
Immediately afterwards, the researchers evaluated B. The mycelial growth, conidia production and germination of the fuckeliana species, and the addition of essential oils to the medium, using different test essential oils, found that peppermint worked best on it.
Recent findings suggest that M. spicata may be a potentially efficient and safe alternative to the controlled storage of fresh products in B. spicata. Cinerea's fumigant, whose main components are pineone, limonene and papaya alcohol, was immediately tested for antifungal activity against rot, Lit. and late blight.
Volatile oils show obvious antifungal activity against plant pathogenic fungi, and the oil concentration it uses is twice as high as ours, not only that, volatile oils also show significant activity against Xanthomonas citrus.
Therefore, M. suaveolens, the most effective essential oil currently known, shows strong antifungal activity against Aspergillus niger. And M. The biological activity of suaveolens has been widely described, the most representative of which is the compound mentholone oxide.
It can be used not only for antifungal and antioxidant activity, but also as a food additive and flavoring agent due to its low risk in use.
epilogue
Through this study, we know that menthol and mentholone are the main compounds in spearmint, and menthol and mentholone are the main compounds in M. menthol. The main compounds in piperita, while menthone oxide and menthone oxide are M. piperita. The main compound in suaveolens.
Ficus is the most sensitive of all the fungi tested, and while these three essential oils inhibited their growth, they also obtained the best results of antifungal activity at doses of 400 μg/mL, yielding a maximum growth inhibition of 100% in all fungi studied, except for Fusarium with an inhibition rate of 94.21%.
Peppermint essential oil has a variety of ingredients, mainly including menthol and menthol nitrile, which give it its unique aroma and efficacy. It has also been shown to have a strong antibacterial effect and can be used for oral and skin care, so when used correctly, peppermint essential oil can be a natural antibacterial option and provide beauty and health benefits.