The postharvest life of most fruit, vegetables and cereals is limited by fungal proliferation. The chemical composition of Mentha piperita, M. spicata and M. suaveolens essential oils (EO), and the ...antifungal activity against four pathogenic and post-harvest fungi isolated from food, were herein investigated to evaluate their potential as natural food preservatives. The EO were obtained by hydrodistillation of aerial parts leaves, stems and inflorescences (except for peppermint oil, which was purchased in a specialized store) and submitted to GC-MS and GC-FID analysis. Regarding the EO composition, carvone (41.1%) and limonene (14.1%) were the major compounds in M. spicata, menthol (47.0%) and menthone (23.1%), as well as other menthol derivatives (neomenthol -3.6%- and menthofurane -3.7%-) in M. piperita, and piperitone oxide (40.2%) and piperitenone oxide (31.4%) in M. suaveolens. Botryotinia fuckeliana was the most sensitive fungus. The three studied EO inhibited growth by 92–100%. The highest dose of M. suaveolens EO, 400 µg/mL, produced 100% MGI in all the studied fungi, except Fusarium oxysporum with 94.21%. The M. suaveolens EO can be considered to develop a low-risk enviro-friendly botanical biofungicide.
The European Union is promoting regulatory changes to ban fungicides because of the impact their use has on the ecosystem and the adverse effects they can pose for humans. An ecofriendly alternative ...to these chemicals to fight against fungal species with low toxicity is essential oils and their compounds extracted from aromatic plants. The purpose of this study was to evaluate the in vitro antifungal capacity of the botanical compounds eugenol, carvacrol, thymol, and cinnamaldehyde, and the synergy or antagonism of their mixtures, against
and
. Different bioassays were performed at doses of 300, 200, 150, and 100 µg/mL using pure commercial compounds and their combination in potato dextrose agar culture medium. Growth rate and the mycelium growth inhibition parameters were calculated. Phenolic compounds and their combination inhibited the development of species at the different concentrations, with fungicidal or fungistatic activity shown under almost all the tested conditions. When comparing the growth rates of the species in the control plates and treatments, the statistical analysis showed that there were statistically significant differences. The mixture of compounds improved fungicidal activity against the studied species and at a lower concentration of monoterpenes.
Fungal pathogens cause major yield losses in agriculture and reduce food quality and production worldwide.
To evaluate new safer alternatives to chemicals for disease management and preserve the ...shelf life of food, this research was conducted to: determine the chemical composition of the essential oils (EOs) of
and
chemotypes 1 and 2; investigate the antifungal potential of EOs
against:
,
,
,
f. sp.
,
,
; evaluate a natural
extract biofilm to conserve rice grain and cherry tomatoes.
EOs were analyzed by GC-MS+GC-FID. EOs' antifungal activity was evaluated by dissolving
extracts in PDA. Petri dishes were inoculated with disks of each fungus and incubated at 25°C for 7 days.
The
EO displayed the best Mycelial Growth Inhibition. The antifungal effect of the
EO biofilm was evaluated on rice caryopsis. Disinfected grains were dipped in a conidial suspension of each fungus and sprayed with EO (300 and 600 μg/mL) prepared in Tween 20. Grains were stored. The percentage of infected grains was recorded for 30 days. The
EO effect on cherry tomato conservation was evaluated
. Wounded fruit were immersed in the
EO (300 and 400 μg/mL) and inoculated with
f. sp.
. Fruit were evaluated for 7 and 14 days. Chemical profiles thymol/carvacrol for
, carvacrol for
Tp1 and thymol for
Tp2 were defined. The three evaluated EOs reduced all the studied phytopathogens' fungal growth. The
biofilm was effective with rice storage and against
f. sp.
for extending the shelf life of tomatoes in warehouses and storing postharvest cherry tomatoes.
We suggest applying these EOs as biofilms for safe food conservation to replace synthetic products.
The chemical composition of Essential Oils Satureja montana and Mentha longifolia was determined, and their activity against important phytopathogenic and post-harvest fungi was studied, to evaluate ...their potential as natural food preservatives. The major compounds were carvacrol (24.0%), γ-terpinene (15.9%) and p-cymene (14.2%) in S. montana, and piperitenone oxide (52.7%) and piperitone oxide (23.5%) in M. longifolia. EOs were tested in vitro on Alternaria alternata, Botryotinia fuckeliana, Curvularia hawaiiensis, Fusarium equiseti, F. oxysporum lycopersici, Rhizoctonia solani and Verticillium dahliae. S. montana demonstrated excellent results. At 300 μg mL−1 the growth of all fungi was inhibited with 100% mycelial growth inhibition (MGI), except for B. fuckeliana (92%). M. longifolia was less effective, and its best result was against Verticillium dahliae (100% MGI) at 400 and 300 μg mL−1. S. montana EO was selected for in vivo antifungal tests in Cherry tomatoes and kaki “Persimmon” against A. alternata. The S. montana EO biofilm reduced post-harvest fungi development. In tomato, it inhibited up to 90% after 20 days. Necrosis did not occur for 2 months in the persimmon fruits. S. montana EO is an effective non-toxic preservative that can be considered to develop a botanical and enviro-friendly low-risk biofungicide.
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•Satureja montana and Mentha longifolia EOs were tested as food preservatives.•The in vitro tested Satureja montana EO showed great antifungal activity.•A natural biodegradable Satureja montana EO biofilm was developed.•The S. montana EO biofilm controlled Alternaria alternata in tomato and kaki.•The composition of the EOs was determined by CG and GC/MS.
Chemical composition of commercial Origanum compactum and Cinnamomum zeylanicum essential oils and the antifungal activity against pathogenic fungi isolated from Mediterranean rice grains have been ...investigated. Sixty-one compounds accounting for more than 99.5% of the total essential oil were identified by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Carvacrol (43.26%), thymol (21.64%) and their biogenetic precursors p-cymene (13.95%) and γ-terpinene (11.28%) were the main compounds in oregano essential oil, while the phenylpropanoids, eugenol (62.75%), eugenol acetate (16.36%) and (E)-cinnamyl acetate (6.65%) were found in cinnamon essential oil. Both essential oils at 300 μg/mL showed antifungal activity against all tested strains. O. compactum essential oil showed the best antifungal activity towards Fusarium species and Bipolaris oryzae with a total inhibition of the mycelial growth. In inoculated rice grains at lower doses (100 and 200 μg/mL) significantly reduced the fungal infection, so O. compactum essential oil could be used as ecofriendly preservative for field and stored Valencia rice.
Fusarium sudanense is a novel fungus recently isolated from asymptomatic samples of wheat grains in Argentina. The fungus caused symptoms of seedling blight and seed rot on wheat after artificial ...inoculations. It is known that the production of mycotoxins by pathogens belonging to the Fusarium genus is harmful to human and animal health. Moreover, the warm and humid conditions that are favorable for growth and mycotoxin production of these species put the Argentinian wheat production area at a high risk of mycotoxin contamination with this novel pathogen. The aim of this work was to evaluate the antagonistic effect of Trichoderma harzianum against F. sudanense under in vitro tests at different environmental conditions. Fungi were screened in dual culture at different water activities (αw) (0.995, 0.98, 0.95, and 0.90) and temperatures (25 and 15 °C). The growth rate of the fungi, interaction types, and dominance index were evaluated. Also, the interaction between T. harzianum and F. sudanense was examined by light and cryo-scanning microscopy. T. harzianum suppressed the growth of F. sudanense at 0.995, 0.98, and 0.95 αw at 25 °C and 0.995 and 0.98 αw at 15 °C. Macroscopic study revealed different interaction types between F. sudanense and T. harzianum on dual culture. Dominance on contact where the colonies of T. harzianum overgrew the pathogen was the most common interaction type determined. The competitive capacity of T. harzianum was diminished by decreasing the temperature and αw. At 0.95 αw and 15 °C, both fungi grew slowly, and interaction type “A” was assigned. Microscopic analysis from the interaction zone of dual cultures revealed an attachment of T. harzianum to the F. sudanense hyphae, penetration with or without formation of appressorium-like structures, coiling, plasmolysis, and a veil formation. According to our results, T. harzianum demonstrated capability to antagonize F. sudanense and could be a promising biocontrol agent.
Agrowastes are produced worldwide in huge quantities and they contain interesting elements for producing inorganic cementing binders, especially silicon. Conversion of agrowastes into ash is an ...interesting way of yielding raw material used in the manufacture of low-CO2 binders. Silica-rich ashes are preferred for preparing inorganic binders. Sugarcane leaves (Saccharum officinarum, SL) and bamboo leaves (Bambusa vulgaris, BvL and Bambusa gigantea, BgL), and their corresponding ashes (SLA, BvLA, and BgLA), were chosen as case studies. These samples were analyzed by means of optical microscopy, Cryo-scanning electron microscopy (SEM), SEM, and field emission scanning electron microscopy. Spodograms were obtained for BvLA and BgLA, which have high proportions of silicon, but no spodogram was obtained for SLA because of the low silicon content. Different types of phytoliths (specific cells, reservoirs of silica in plants) in the studied leaves were observed. These phytoliths maintained their form after calcination at temperatures in the 350-850°C range. Owing to the chemical composition of these ashes, they are of interest for use in cements and concrete because of their possible pozzolanic reactivity. However, the presence of significant amounts of K and Cl in the prepared ashes implies a limitation of their applications.
The Mediterranean Basin is particularly rich in aromatic plants with essential oils whose composition and properties are still to be investigated. The aims of this work were to: investigate the ...chemical composition of essential oils from three typical Spanish aromatic species: Artemisia herba-alba, Artemisia absinthium and Mentha longifolia; evaluate the antifungal potential of essential oils against seven plant pathogenic and postharvest fungi; analyse the effectiveness of the Mentha longifolia essential oil in extending the blueberry fruit shelf life. The main compounds for the Artemisia herba-alba essential oil were camphor (29.8%), trans-thujone (22%), 1,8-cineole (14.5%) and cis-thujone (10.8%). In the A. absithium essential oil, they were cis-cryshanthemyl acetate (35.4%), cis-β-epoxiocimene (36%) and trans-β-epoxiocimene (10.4%). α-Terpineol acetate (32.6%), pulegone (14.2%) and 8-acetoxy carvotanacetone (10.3%) were the most important molecules in the obtained composition of the Mentha longifolia essential oil. Different bioassays were performed at the 300 μg/mL and 600 μg/mL doses using the distinct essential oils in potato dextrose agar culture medium. The Artemisia herba-alba and Artemisia absinthium essential oils at 300 μg/mL were not very effective. The Mentha longifolia essential oil strongly inhibited mycelial growth at the two tested doses, but it totally inhibited the growth of Curvularia hawaiiensis, Fusarium nygamai and Verticilliun dahliae at 600 μg/mL. The blueberries coated with the Mentha longifolia essential oil solution obtained a statistically higher percentage of healthy fruit than the control. They could be considered an ecofriendly alternative for postharvest treatment, and for maintaining the quality and turgidity of these berries during storage.
The postharvest life of most fruit and vegetables is limited by fungus proliferation. The Aloe vera gel was added at different concentrations to test its antifungal potential against five fungi ...(Rhizoctonia solani, Curvularia hawaiiensis, Botryotinia fuckeliana, Penicillium italicum, Verticillium dahliae), which cause significant losses in basic agricultural products included in the world's diet: tuber potato, cereals, fruit and vegetables. The best results were for the fungus Verticillium dahlie, with a mycelial growth inhibition of 100% and 70% at 200 and 100 mL/L, respectively. Satisfying results were for fungi R. solani and B. fuckeliana, where the mycelial growth inhibition exceeded 50% in them all at 200 mL/L. Antifungal activity was maintained in B. fuckeliana by lowering the dose to 100 mL/L. The Aloe vera extract at 300 mL/L was applied as a coating in the postharvest treatment to blueberry fruit at 21 °C and 85% humidity. When the experiment ended, the percentage of rotted berries was significantly lower in the treated than in the control. The Aloe vera gel could be considered a promising postharvest treatment to maintain blueberry quality and turgor during storage.
•Aloe vera leaf extract inhibited postharvest fungi in a dose-dependent manner.•Verticillium dahliae had the best results with total inhibition of mycelial growth.•Antifungal activity was maintained in B. fuckeliana by lowering the dose.•The natural film created extended shelf life and maintained blueberry quality.
The chemical composition of commercial Syzygium aromaticum, Cinnamomum verum, and Laurus nobilis essential oils as well as their antifungal activity against four pathogenic fungi isolated from ...Mediterranean rice grains has been investigated. Eighty nine compounds accounting for between 98.5 and 99.4% of the total essential oil were identified. The phenylpropanoids eugenol (89.37 ± 0.29%) and eugenol (56.34 ± 0.41%), followed by eugenol acetate (19.48 ± 0.13%) were, respectively, the main compounds in clove and cinnamon essential oils, whereas large amounts of the oxygenated monoterpenes 1,8-cineole (58.07 ± 0.83%) and α-terpinyl acetate (13.05 ± 0.44%) were found in bay leaf essential oil. Clove and cinnamon oils showed the best antifungal activity results against all tested fungi. Against Alternaria alternata, clove essential oil displayed the best antifungal effect, whereas against Curvularia hawaiiensis, cinnamon essential oil was more active. Both essential oils showed a similar antifungal effect towards Fusarium proliferatum and Fusarium oxysporum. In vitro studies in inoculated rice grains showed that clove and cinnamon totally inhibited pathogenic fungal development after 30 days of incubation. In vivo studies showed that eugenol used with a polysaccharide such as agar–agar formed a fine coat which wraps the inoculated rice grains, creating a natural biofilm and reducing the development of all pathogenic fungi (80–95%) for 30 days.
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