Efficacy of Some Essential Oils Against Aspergillus flavus with Special Reference to Lippia alba Oil an Inhibitor of Fungal Proliferation and Aflatoxin B1 Production in Green Gram Seeds during Storage

During mycofloral analysis of green gram (Vigna radiata (L.) R. Wilczek) seed samples taken from different grocery stores by agar and standard blotter paper methods, 5 fungal species were identified, of which Aspergillus flavus exhibited higher relative frequency (75.20% to 80.60%) and was found to produce aflatoxin B₁. On screening of 11 plant essential oils against this mycotoxigenic fungi, Lippia alba essential oil was found to be most effective and showed absolute inhibition of mycelia growth at 0.28 μL/mL. The oil of L. alba was fungistatic and fungicidal at 0.14 and 0.28 μL/mL, respectively. Oil had broad range of fungitoxicity at its MIC value and was absolutely inhibited the AFB1 production level at 2.0 μL/mL. Chemical analysis of this oil revealed geranial (36.9%) and neral (29.3%) as major components followed by myrcene (18.6%). Application of a dose of 80 μL/0.25 L air of Lippia oil in the storage system significantly inhibited the fungal proliferation and aflatoxin production without affecting the seed germination rate. By the virtue of fungicidal, antiaflatoxigenic nature and potent efficacy in storage food system, L. alba oil can be commercialized as botanical fungicide for the protection of green gram seeds during storage.     

Short communication: Cheese supplemented with Thymus algeriensis oil,a potential natural food preservative

The essential oil of Thymus algeriensis was analyzed as a potential preservative in soft cheese. We developed a novel method to test the preserving properties of essential oil in soft cheese. Contamination incidence of Penicillium aurantiogriseum was absent after 30 d of storage at 4°C with 25 µL of essential oil added. The antimicrobial activity was tested against 8 bacteria and 8 fungi. Thymus algeriensis oil showed inhibitory activity against tested bacteria at 0.03 to 0.09 mg/mL, and bactericidal activity was achieved at 0.05 to 0.15 mg/mL. For antifungal activity, minimum inhibitory concentrations ranged between 0.01 and 0.04 mg/mL and minimum fungicidal concentrations between 0.01 and 0.04 mg/mL. Furthermore, the oil was also screened for antiradical activity using the 1,1-diphenyl-2-picrylhydrazyl assay. The results showed that the oil was active and achieved half-maximal inhibitory activity at 0.132 mg/mL. We used gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectrometry to investigate the volatile compounds from the oil. Carvacrol was identified as the main compound in the oil, represented by 80.9% of the total constituents, followed by p-cymene (7.7%).     

Chemical composition and in vitro control of agricultural plant pathogens by the essential oil and various extracts of Nandina domestica Thunb.

BACKGROUND: The aims of this study were to examine the chemical composition of the essential oil isolated from the floral parts of Nandina domestica Thunb. by hydrodistillation, and to test the efficacy of essential oil and various leaf extracts (n‐hexane, chloroform, ethyl acetate and methanol) as an antifungal potential against a panel of agricultural plant pathogens. RESULTS: The GC‐MS analysis determined that 79 compounds, which represented 87.06% of total oil, were present in the oil containing mainly 1‐indolizino carbazole (19.65%), 2‐pentanone (16.4%), mono phenol (12.1%), aziridine (9.01%), methylcarbinol (4.6%), ethanone (3.3%), furfural (2.96%), 3,5‐dimethylpyrazole (1.29%) and 2(5H)‐furanone (1.32%). The oil (1000 ppm disc^?1) and the leaf extracts (1500 ppm disc^?1) revealed remarkable antifungal effect against Fusarium oxysporum, Fusarium solani, Phytophthora capsici, Colletotrichum capsici, Sclerotinia sclerotiorum, Botrytis cinerea and Rhizoctonia solani in the growth inhibition range of 53.3–64.3% and 33.3–56.0%, respectively, along with their respective values for mimimum inhibitory concentration (MIC) ranging from 125 to 1000 µg mL^?1 and 500 to 2000 µg mL^?1. The values for minimal fungicidal concentration (MFC) of the oil and extracts were obtained in the range of 125 to 1000 µg mL^?1 and 500 to 2000 µg mL^?1, respectively. The essential oil also had a strong detrimental effect on spore germination of all the plant pathogens tested along with concentration as well as time‐dependent kinetic inhibition of B. cinerea. CONCLUSION: The results obtained in this study demonstrate that N. domestica mediated oil and extracts could become potential alternatives to synthetic fungicides for controlling certain important agricultural plant pathogenic fungi. Copyright © 2008 Society of Chemical Industry     

Synergistic antifungal effects of thyme essential oil and Lactobacillus plantarum cell‐free supernatant against Penicillium spp. and in situ effects

This study evaluates the synergistic antifungal effects between thyme essential oils and Lactobacillus plantarum cell‐free supernatant (LCFS) against Penicillium spp. and in situ antifungal activity in rice grains. Thyme essential oil and LCFS showed remarkable antifungal activities against Penicillium spp. with the minimum inhibitory concentration (MIC) of 40 and 80 µL/mL, respectively. The analysis of fractional inhibitory concentration (FIC) index showed the antifungal synergism between thyme essential oil and LCFS against Penicillium spp. with FIC index of 0.5. This synergism also resulted in fourfold reduction in their MICs when applied in combination. The antifungal modes of action were characterized by observing the changes in cell membrane permeability and degradation of fungal cell wall. The combination of thyme essential oil and LCFS (2 × MIC of each) showed remarkable in situ antifungal effect and completely inhibit the growth of Penicillium in rice seeds. The results suggested the possible applications of the observed synergism on actual crops.

Practical applications

Essential oils are used as preservative in food industry and high concentration of essential oil is associated with negative organoleptic characteristics. This study presented a novel approach for synergistic antifungal effects by using the combination of thyme essential oil and Lactobacillus plantarum cell‐free supernatant (LCFS) against Penicillium spp. and systematic evaluation of the antifungal effect by using fractional inhibitory concentration (FIC) index method. This approach will be a role model for future research on synergism and overcome the major drawbacks of using live bacteria and the negative effects arising from antimicrobial activities of essential oils.     

Antioxidative activity of Rosmarinus officinalis L. essential oil compared to its main components

This study was designed to examine the in vitro antioxidant activities of Rosmarinus officinalis L. essential oil compared to three of its main components (1,8-cineole, α-pinene, β-pinene). GC–MS analysis of the essential oil resulted in the identification of 19 compounds, representing 97.97% of the oil, the major constituents of the oil were described as 1,8-cineole (27.23%), α-pinene (19.43%), camphor (14.26%), camphene (11.52%) and β-pinene (6.71%). The oil and the components were subjected to screening for their possible antioxidant activity by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and β-carotene bleaching test. In the DPPH test system, free radical-scavenging activity of R. officinalis L. essential oil, 1,8-cineole, α-pinene and β-pinene were determined to be 62.45% ± 3.42%, 42.7% ± 2.5%, 45.61% ± 4.23% and 46.21% ± 2.24% (v/v), respectively. In the β-carotene bleaching test system, we tested series concentration of samples to show the antioxidant activities of the oil and its main components, whereas the concentrations providing 50% inhibition (IC₅₀) values of R. officinalis L. essential oil, 1,8-cineole, α-pinene and β-pinene were 2.04% ± 0.42%, 4.05% ± 0.65%, 2.28% ± 0.23% and 2.56% ± 0.16% (v/v), respectively. In general, R. officinalis L. essential oil showed greater activity than its components in both systems, and the antioxidant activities of all the tested samples were mostly related to their concentrations. Antioxidant activities of the synthetic antioxidant, ascorbic acid and BHT, were also determined in parallel experiments as positive control.     

The essential oil from Heteropyxis natalensis harv: Its antimicrobial activities and phytoconstituents

The essential oil obtained from Heteropyxis natalensis by steam distillation was tested for antimicrobial properties. Twenty five bacterial and four fungal species were used as test organisms in this study. These included animal and plant pathogens, food poisoning bacteria and mycotoxigenic fungal strains. The essential oil exhibited considerable inhibitory activities against all the test organisms. GC–MS analysis indicated the essential oil contained 1,8-cineole, limonene, β-myrcene, α-phellandrene and α-pinene.     

Chemical composition and antioxidant and antimicrobial activities of essential oil of Allium sphaerocephalon L. subsp. sphaerocephalon (Liliaceae) inflorescences

BACKGROUND: Allium sphaerocephalon is a wild‐growing plant commonly used as an onion substitute. In this study the essential oil obtained from A. sphaerocephalon subsp. sphaerocephalon inflorescences was analysed by gas chromatography and gas chromatography/mass spectrometry and also evaluated for in vitro antioxidant and antimicrobial activities. The obtained results are reported for the first time and discussed with respect to the sulfur compounds detected in the essential oil. RESULTS: Ninty‐one compounds were identified, representing 91.6% (w/w) of the total oil. Major constituents of the analysed sample were shyobunol (15.3%), β‐caryophyllene (8.1%), α‐cadinol (7.8%), 3,5‐diethyl‐1,2,4‐trithiolane (isomer II, 5.9%) and δ‐cadinene (5.2%). The diluted oil had an antioxidant capacity of 160 000 ± 111 µmol α‐tocopherol acetate equivalents g^?1. Its antimicrobial activity was evaluated against five bacterial and two fungal strains using the broth microdilution assay. Among the micro‐organisms tested, the most susceptible strains were Pseudomonas aeruginosa (minimal inhibitory/bactericidal concentration = 0.08/2.5 mg mL^?1) and Aspergillus niger (minimal inhibitory/fungicidal concentration = 0.31/0.63 mg mL^?1). CONCLUSION: The results showed that the examined species had strong antioxidant and antimicrobial properties and are in accordance with the popular use of plants belonging to the genus Allium in traditional medicine, emphasising the necessity of further detailed study of the active principles in Allium species. Copyright © 2010 Society of Chemical Industry     

High-Performance Liquid Chromatography-Diodic Array Detector,Fungistatic, and Anti-Morphogenical Analysis of Extracts from Psidium brownianum Mart. ex DC. Against Yeasts of the Genus Candida

We assessed extracts from Psidium brownianum for antifungal activity and identified the phenolic phytocompounds. Minimum inhibitory concentration was determined by microdilution and IC₅₀ was calculated. The minimun fungicidal concentration and the morphology of Candida were evaluated. Extracts analyzed by high-performance liquid chromatography demonstrated flavonoids and phenolic acids. The minimum inhibitory concentration was 8192 µg/mL and the IC₅₀ varied between 1056 and 5128 µg/mL. Extracts showed fungistatic effect and altered the dimorphism of the strains, being the better result observed using the decoction, that affected the fungal dimorphism of the strain CA ATCC40006 at 4096 µg/mL.     

Chemical Composition and Antidiabetic Activity of Essential Oils Obtained from Two Spices (Syzygium aromaticum and Cuminum cyminum)

The current aim was to evaluate antidiabetic potential of Syzygium aromaticum and Cuminum cyminum essential oils and their emulsions by alpha amylase inhibition assay. Antidiabetic activity of C. cyminum and S. aromaticum was examined in dose dependent mode (1 to 100 µg/mL). The maximum antidiabetic activity for S. aromaticum and C. cyminum essential oils was noted at the highest dose (100 µg/mL). Five emulsions (essential oil + surfactant [tween 80] + co-surfactant [ethanol] + water) of different concentrations for S. aromaticum (A1 to A5) and C. cyminum (B1 to B5) essential oils were formulated. Among different emulsions, A5 of S. aromaticum and B5 of C. cyminum essential oil exhibited a maximum antidiabetic activity with 95.30 and 83.09% inhibition of α-amylase, respectively. Moreover, the analysis of essential oils showed that eugenol (18.7%) and α-pinene (18.8%) were the major components of S. aromaticum and C. cyminum essential oils, respectively.     

Determination of Chemical Composition,Total Phenolic,Antimicrobial, and Antioxidant Activities of Echinophora tenuifolia Essential Oil

In this study, the antioxidant and antimicrobial activities, total phenolic content, and essential oil composition of Echinophora tenuifolia L. subsp. sibthorpiana were investigated. The antioxidant activity of investigated essential oil was assessed by ABTS and DPPH assays. DPPH radical scavenging activity expressed by IC₅₀ was 2.84 g/L, whereas the TEAC value determined by ABTS assay was 0.032 g TEAC/kg plant. Total phenol content of essential oil determined by Folin-Ciocalteu method was calculated as 1.32 g GAE/kg plant. The essential oil extracted by hydrodistillation (Clevenger apparatus) was investigated by GC-MS technique and 78 compounds were identified. The main components of essential oils were found to be δ-3-carene (17.93%), p-cymene (8.99%), methyleugenol (16.41%), and α-phellandrene (9.33%). The antimicrobial activity of investigated essential oil was tested using a broth dilution method against 13 bacterial and 2 fungal microorganisms. The lowest minimum inhibitory concentration of essential oil against Bacillus cereus was 62.5 μg/mL while the antifungal activity was greater than 1000 μg/mL for both Candida albicans and Saccharomyces cereviciae. Investigated essential oil has a certain level of antioxidant and antimicrobial effects, which may be attributed to their chemical compounds. The antimicrobial efficiency of essential oil, especially against Bacillus cereus and Staphylocoocus spp., offers its effectiveness to treatment of wound or disease caused by Gram positive bacteria.     

Effect of Zingiber officinale Roscoe essential oil in fungus control and deoxynivalenol production of Fusarium graminearum Schwabe in vitro

ABSTRACT

Members of the Fusarium genus are capable of contaminating agricultural commodities, compromising the quality of maize and other grains, which leads to severe quality and yield losses. Contamination with mycotoxins is also a concern. Essential oils are possible alternatives to the use of synthetic pesticides for control of fungal contamination, as many have antifungal and anti-mycotoxigenic properties and are innocuous to human health. They also do not cause any sort of microbial resistance and do not promote environmental pollution. The aim of this study was to evaluate the antifungal and anti-mycotoxigenic effects of Zingiber officinale Roscoe essential oil (GEO) upon Fusarium graminearum Schwabe in vitro. The essential oil was extracted by hydrodistillation and analysed by GC/MS. Antifungal and anti-mycotoxigenic activities were assessed by HPLC/UV by quantifying ergosterol and deoxynivalenol (DON), respectively. Results indicated that GEO inhibited ergosterol production at a concentration of 1000 µg/mL and DON production at a concentration of 500 µg/mL, evidencing that the anti-mycotoxigenic effect is independent of the antifungal effect due to its probable direct action upon toxin biosynthesis.     

Chemical composition,antibacterial and antifungal activities of seed essential oil of Ferulago angulata

The aim of this study was to determine the chemical composition and the in vitro antimicrobial effects of seed essential oil of Ferulago angulata. The oil analyses by GC and GC/MS resulted in the identification of 39 compounds representing 91.07% of the oil. The major constituents were (Z)-β-ocimene (19.93%), α-pinene (15.50%), p-cymene (7.67%), sabinene (7.49%), β-phellandrene (5.5%), and α-phellandrene (4.95%). The oil was also screened for its antimicrobial properties against six bacteria (Erwinia amylovora, Xanthomonas oryzae, Pseudomonas syringae, Pectobacterium carotovorum, Ralstonia solanacearum, Bacillus thuringiensis) and six fungi (Alternaria alternata, Culvularia fallax, Macrophomina phaseolina, Fusarium oxysporum, Cytospora sacchari, Colletotrichum tricbellum). According to the results of antibacterial activity, B. thuringiensis (with 8 µL mL^?1 minimal inhibitory concentration (MIC) and 15 µL mL^?1 minimum bactericidal concentration (MBC)) was the most sensitive bacterium; P. carotovorum and R. solanacearum (with 20 µL mL^?1 MIC and 30< MBC) were the most resistant bacteria. Additionally, a broad differentiation against all of the tested fungi showed that the most susceptible and resistant fungi after 6 days at the highest concentration (800 µL L^?1) were F. oxysporum (100.0 ± 0.00%) and C. tricbellum (52.50 ± 1.67%) of growth inhibition, respectively.     

砂糖橘精油化学组成及对指状青霉的抑菌活

采用水蒸气蒸馏法提取砂糖橘(Citrus reticulate Blanco)果皮精油,并用GC-MS对其成分进行分析,共鉴定出17种成分,主要包括柠檬烯(77.99%)、β-月桂烯(3.74%)、β-水芹烯(2.78%)、罗勒烯(2.64%)、β-芳樟醇(2.35%)、α-蒎烯(1.60%)、正辛醇(1.54%)、癸醛(1.24%)、4-松油醇(1.10%)和4-十一烯(1.04%)等。测定不同添加量(0.16、0.31、0.63、1.25、2.50、5.00、10.00μL/mL)砂糖橘精油对指状青霉孢子萌发和菌丝体生长的作用。结果表明：低添加量(＜2.5μL/mL)砂糖橘精油对指状青霉孢子萌发无影响甚至有促进作用,对指状青霉菌丝体生长有轻微的抑制;而高添加量(10μL/mL)则显著抑制孢子萌发和菌丝体生长(P＜0.05)。本实验表明砂糖橘精油在防治指状青霉具有一定作用。     

Chemical Composition,Antimicrobial, and Antioxidant Activities of Essential Oil and Ethanol Extract of Coriandrum sativum L. Leaves from Turkey

This study reports the chemical composition, antioxidant, and antimicrobial activity of the essential oil and ethanol extract of Coriandrum sativum L. leaves. Gas chromatography/mass spectrometry analysis identified 19 compounds representing 95.30% of the oil. (E)-2-decenal (29.87%), linalool (21.61%), (E)-2-dodecenal (7.03%), dodecanal (5.78%), (E)-2-undecenal (3.84%), (E)-2-tridecenal (3.56%), (E)-2-hexadecenal (2.47%), tetradecenal (2.35%), and α-pinene (1.64%) were the main components identified in the essential oil. The samples were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging and β-caroten bleaching assay. IC₅₀ value for ethanol extract of C. sativum was determined as 74.87 ± 0.03 μg/mL. Total antioxidant activity value for C. sativum ethanol extract was 85.85 ± 0.04%. Total phenolic content for ethanol extract of the plant was determined as 14.97 ± 0.05 mg gallic acid equivalents/g dry weight. The essential oil and ethanol extract were also tested for antimicrobial activity against 28 different foodborne microorganisms, including 19 bacteria, 7 fungi, and 2 yeast species. The ethanol extract of the plant showed weak antimicrobial activities against microbial strains in both disc diffusion and minimal inhibition concentration tests. This study suggested that Coriandrum sativum L. leaves may be used as a potential source of food flavoring, and for their antioxidants and antimicrobial properties.     

Daphne oleoides: An alternative source of important sesquiterpenes

This study was targeted to characterize the chemical composition and antibacterial properties of Daphne oleoides subsp. oleoides essential oil. The essential oil was analyzed and quantified by gas chromatography and gas chromatography/mass spectrometry. Additionally, the broth dilution method was used to evaluate its antibacterial activity against Bacillus cereus (ATCC 11778), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Streptococcus faecalis (ATTC 29212), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 25933), Proteus vulgaris (ATCC 13315), Pseudomonas aeruginosa (ATCC 27853), and Salmonella typhi Ty2 (ATCC 19430). Seventy-nine compounds were identified, representing 95.2% of the total oil. Nootkatone (18.5%), nootkatin (12.1%), and daphnauranol C (11.7%) were determined as the main constituents in the oil. Oxygenated sesquiterpenes were dominating in the oil (43.0%), followed by fatty acid derivatives (13.7%) and carbonylic compounds (9.6%). The minimal inhibitory/bactericidal concentrations of essential oils of D. oleoides were in the range from 25–100 μg/mL, which can be considered as high activity in comparison with the reference antibiotic which was active in the rangefrom 3.12–100 μg/mL. The greatest minimal inhibitory concentration value was determined as 25 µg/mL against both two Bacillus strains and S. epidermidis, B. cereus, B. subtilis, and S. aureus were the most sensitive strains against essential oils when compared with the minimal inhibitory concentrations of control antibiotic. Consequently, Daphne oleoides subsp. oleoides can be exploited as a source of natural antibacterial agents and nootkatone for the pharmaceutical, food, and agricultural industries.     

Biological activity of Boswellia serrata Roxb. oleo gum resin essential oil: effects of extraction by supercritical carbon dioxide and traditional methods

The findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.     

Chemical Composition and Antimicrobial Activity of Essential Oil of Matricaria recutita

Matricaria recutita is a herbaceous plant belonging to the Asteraceae family. The present study reports the chemical composition and antimicrobial activity of M. recutita essential oil and its main compounds. The essential oil was obtained from the aerial parts of the M. recutita by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components were α-bisabolol oxide (38%), followed by camphene (9.11%), sabinene (4.87%), limonene (6%),1,8-cineole (7.12%), camphor (6.54%), and α-pinene (6%). Essential oil of chamomile was evaluated for its antibacterial activities against three gram-positive and four gram-negative pathogenic bacteria. The essential oil and its main compounds were particularly active against Bacillus cereus, with the lowest minimum inhibitory concentration and minimum bactericidal concentration value (0.022 and 1.5 μg /mL). In conclusion, these results support the use of the essential oil and its main compounds for their antimicrobial properties.     

Chemical Composition and Anticancer and Antioxidant Activities of Schinus Molle L. and Schinus Terebinthifolius Raddi Berries Essential Oils

Abstract: Essential oils were obtained by steam distillation from berries of Schinus molle L. and Schinus terebinthifolius Raddi originating from southern of Tunisia and analyzed by GC-FID and GC-MS. Among 57 and 62 compounds (%[mg/100 g dry matter]) identified in these oils, the main were α-phellandrene (46.52%[1256.15] and 34.38%[859.60]), β-phellandrene (20.81%[561.74] and 10.61%[265.15]), α-terpineol (8.38%[226.26] and 5.60%[140.03]), α-pinene (4.34%[117.29] and 6.49%[162.25]), β-pinene (4.96%[133.81] and 3.09%[77.30]) and p-cymene (2.49%[67.28] and 7.34%[183.40]), respectively. A marked quantity of γ-cadinene (18.04%[451.05]) was also identified in the S. terebinthifolius essential oil whereas only traces (0.07%[1.81]) were detected in the essential oil of S. molle. The in vitro antioxidant and antiradical scavenging properties of the investigated essential oils were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Essential oil of S. terebinthifolius expressed stronger antioxidant activity in the ABTS assay, with an IC₅₀ of 24 ± 0.8 mg/L, compared to S. molle (IC₅₀= 257 ± 10.3 mg/L). Essential oils were also evaluated for their anticancer activities against human breast cancer cells (MCF-7). S. terebinthifolius essential oil was more effective against tested cell lines (IC₅₀= 47 ± 9 mg/L) than that from S. molle (IC₅₀= 54 ± 10 mg/L). Suggestions on relationships between chemical composition and biological activities are outlined.     

Original article: Antifungal activities of cinnamon oil against Rhizopus nigricans,Aspergillus flavus and Penicillium expansum in vitro and in vivo fruit test

The postharvest pathogens such as R. nigricans, A. flavas and P. expansum are the causal agents of jujube or orange fruit, therefore, in vitro and in vivo antifungal activities of cinnamon oil to inactivate these fungi were investigated. Cinnamaldehyde is the main constituent of cinnamon oil. The minimum inhibitory concentrations of cinnamon oil against Rhizopus nigricans, Aspergillus flavus and Penicillium expansum were 0.64% (v/v), 0.16% (v/v) and 0.16% (v/v), respectively. The antifungal activity of cinnamon oil against A. flavus and P. expansum was stronger than that against R. nigricans and the activity was improved with increasing its concentration. In an in vivo study, cinnamon oil with concentrations of 2.0% (v/v) and 3.0% (v/v) showed complete control the growth of fungi in wound‐inoculated Lingwu Long Jujube and Sand Sugar Orange fruits. These results revealed that cinnamon oil has a good potential to be as a natural antifungal agent for fruit applications.     

Natural Control of Corn Postharvest Fungi Aspergillus flavus and Penicillium sp. Using Essential Oils from Plants Grown in Argentina

The objective in this study was to evaluate the antifungal activity of essential oils from native and commercial aromatic plants grown in Argentina against corn postharvest fungi and to link the essential oil bioactivity with lipid oxidation and morphological changes in fungus cell membrane. Essential oil (EO) of oregano variety Mendocino (OMen), Cordobes (OCor), and Compacto (OCom), mint variety Inglesa (Mi), and Pehaujo (Mp), Suico (Sui); rosemary (Ro), and Aguaribay (Ag) were tested in vitro against 4 corn fungi: A. flavus (CCC116–83 and BXC01), P. oxalicum (083296), and P. minioluteum (BXC03). The minimum fungicidal concentration (MFC) and the minimum inhibitory concentration (MIC) were determined. The chemical profiles of the EOs were analyzed by GC‐MS. Lipid oxidation in cell membrane of fungi was determined by hydroperoxides and related with essential oil antifungal activity. The major compounds were Thymol in OCor (18.66%), Omen (12.18%), and OCom (9.44%); menthol in Mi and Mp; verbenone in Sui; dehydroxy‐isocalamendiol in Ag; and eucaliptol in Ro. OCor, Omen, and OCom showed the best antifungal activity. No antifungal activity was observed in Ag and Ro EO. The hydroperoxide value depended on the fungi (P < 0.001) and the antimicrobial agent (P < 0.001).Membrane lipids were oxidized by Sui EO in A. flavus BXC01 and A. flavus CCC116–83 (0.021 and 0.027 meqO₂/kg, respectively). The results suggest that the EOs of OCor, OMen, OCom, Mi, Mp, and Sui grown in Argentina can be used as natural alternatives to control fungi that produce mycotoxin in maize.