The Vapor Phase of Selected Essential Oils and Their Antifungal Activity In Vitro and In Situ against Penicillium commune, a Common Contaminant of Cheese

This study aimed to determine the in vitro and in situ antifungal activity of (14) selected essential oils (EOS), namely clove, thyme, red thyme, litsea, eucalyptus, niaouli, fennel, anise, cumin, basil, rosemary, sage, bergamot mint, and marjoram, by vapor contact against the growth of two strains of Penicillium commune (KMi-183 and KMi-402). Furthermore, to exclude the negative effect of EOs on the lactic acid bacteria (LABs) (Streptococcus spp.) on cheeses, their influence was monitored. Next, the sensory evaluation of cheese treated by EOs was evaluated. The results show that litsea and clove EOs were the most effective in the vapor phase against both tested strains. These EOs were characterized by the highest amount of α- (40.00%) and β-Citral (34.35%) in litsea and eugenol (85.23%) in clove. The antitoxicogenic activity of less effective (in growth inhibition) EOs on cyclopiazonic acid (CPA) production by the tested strains was also observed. The growth of Streptococcus spp. (ranging from 8.11 to 9.69 log CFU/g) was not affected by the EOs in treated cheese. Even though the evaluators recognized some EOs in sensory evaluation by the triangle test, they did not have a negative effect on the taste and smell of the treated cheeses and were evaluated as edible. The antifungal activity of EOs against several types of microscopic fungi and their effect on the sensory properties of treated foods needs to be further tested to achieve the most effective protection of foods from their direct contaminants.

The Use of Essential Oils from Thyme, Sage and Peppermint against Colletotrichum acutatum

The Colletotrichum spp. is a significant strawberry pathogen causing yield losses of up to 50%. The most common method to control plant diseases is through the use of chemical fungicides. The findings of plants antimicrobial activities, low toxicity, and biodegradability of essential oils (EO), make them suitable for biological protection against fungal pathogens. The aim is to evaluate the inhibition of Colletotrichum acutatum by thyme, sage, and peppermint EO in vitro on detached strawberry leaves and determine EO chemical composition. Our results revealed that the dominant compound of thyme was thymol 41.35%, peppermint: menthone 44.56%, sage: α,β-thujone 34.45%, and camphor: 20.46%. Thyme EO inhibited C. acutatum completely above 200 μL L^-1 concentration in vitro. Peppermint and sage EO reduced mycelial growth of C. acutatum. In addition, in vitro, results are promising for biological control. The detached strawberry leaves experiments showed that disease reduction 4 days after inoculation was 15.8% at 1000 μL L^-1 of peppermint EO and 5.3% at 800 μL L^-1 of thyme compared with control. Our findings could potentially help to manage C. acutatum; however, the detached strawberry leaves assay showed that EO efficacy was relatively low on tested concentrations and should be increased.

Plants of Nepeta cataria var. citriodora Beck. and essential oils from them for food industry

Nepeta cataria var. citriodora Beck. (catmints) is a source industrial production of citral and attractive raw material for food industry and cooking. Aerial part of Nepeta are characterized by high antimicrobial activity and fungicidal action against mold fungi, used in folk medicine, as ingredient in recipes for sausages, liqueurs and soft drinks, vegetable and fruit canned food, in the manufacture of vermouth. Ukrainian variety 'Melody' was created specifically for growing in the Forest-Steppe zone, and variety 'Peremozhets' – in the Steppe zone. Data on the yield aerial part and essential oil Nepeta was determined. The dry aerial part of plants N. cataria we used to create a dry spicy mixture for sweet dessert dishes. Quantitative content and qualitative composition of essential oil of plants by organs and phases of vegetation are presented in the article. In our research we used essential oils obtained by hydro distillation procedure for 2 h using Clevendger-type apparatus from the flowering parts of plants N. cataria 'Peremozhets' and 'Melody'. Investigate of components was carried out by high effective gas chromatography with HP 6890 chromatograph coupled with HP 5972 mass selective detector. The most abundant components of Nepeta essential oil was citral, geraniol, as well as nerol, citronellol, citronellal, carvacrol, camphor, eugenol. We proposed fractional distillation of essential oils to obtain a line of flavors with stable sensory and physicochemical indicators for food industry. The separation of essential oils into fractions was carried out on a pilot installation of fractional distillation DFD (Device of Fractional Distillation). Calculations of parameters controlled dispersal of essential oils (residual pressure, temperature regimes, number of theoretical plates, reflux number) were carried out. During fractionation of essential oil of N. cataria four fractions were obtained with a content of 96 ±0.5% to the total mass of samples. Sensory and physicochemical analysis of aromatic fractions announced them as promising flavours for food industry.

Antifungal activity of selected essential oils against Fusarium culmorum and F. graminearum and their secondary metabolites in wheat seeds

Essential oils (EOs) are products of plant origin and include mixtures of different chemical compounds. These volatile substances have many interesting properties, including antifungal properties. Fungi may develop under field conditions on crops such as wheat or corn and are able to synthesize mycotoxins, which adversely affect livestock and human health. In the present study, selected EOs were used to inhibit the growth of Fusarium graminearum and F. culmorum and reduce the concentrations of mycotoxins in wheat grain. The EOs significantly inhibited the growth of tested Fusarium species (90.99-99.99%), as determined based on ergosterol quantitative analysis. Only the addition of orange oil to F. culmorum exhibits a different inhibition capacity (68.13%). EO application resulted in a large reduction in zearalenone content (99.08-99.99%); only in the case of orange oil application was the reduction estimated at approximately 68.33%. However, all EOs provided a significant reduction in the concentration levels of group B trichothecenes (94.51-100%). It can be concluded that EOs inhibit the growth of fungi of the genus Fusarium and reduce concentration levels of the mycotoxins zearalenone and group B trichothecenes.

Constituents of the essential oil in Solidago canadensis L. from Eurasia

Hydro distilled essential oils in air-dry samples of aerial parts of Solidago canadensis L., (Asteraceae) from eight local invasive populations were investigated by GC-MS analysis. A comparative study on quantity and composition of the essential oils obtained from plants, growing in different ecological and climatic conditions, ontogenesis phase and different plant organs was carried out The major compounds detected in oil samples of S. canadensis were α-pinene (1.3 - 61.27%), limonene (0.5 - 22.5%), bornyl acetat (3.4 - 29.8%) and germacrene D (1.8 - 39.2%). Samples from inflorescences contained the maximal percentage of monoterpene hydrocarbons, while the leaves' samples showed the maximal cumulative percentage of sesquiterpene and monoterpene hydrocarbons. Data obtained from our studies confirm the availability of alien invasive species Solidago canadensis for medicine and many other purposes. The variability of the qualitative and quantitative composition of essential oils in different geographical locations will allow futher selection of form containing the maximum amount of active substances.