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Inhibitory effect of oregano and thyme essential oils on molds and foodborne bacteria
Abstract
The essential oil of oregano (‘origanum oil’; thymol type oil from Origanum vulgare) inhibited completely the mycelial growth of Aspergillus niger and A. flaous at 400 μg/ml, while A. ochraceus was inhibited at 600 μg/ml. At 700 μg/ml, thyme oil inhibited the mycelial growth of A. flavus and A. niger but not that of A. ochraceus. Fungal spore germination was inhibited by 600 μg/ml of origanum oil and (with the exception of A. ochraceus) by 700 μg/ml of thyme oil. Under aerobic conditions, the essential oils of oregano (250 μg/ml) and thyme (350 μg/ml) inhibited to some extent the growth of Staphylococcus aureus and Salmonella typhimurium. Pseudomonas aeruginosa was not affected by either oregano or thyme oil at concentrations up to 500 μg/ml. The origanum oil was very effective against Campylohacter jejuni and Clostridiurn sporogenes and thyme oil was very effective against C. jejuni. The antagonistic effect of the two oils on Staph. aureus and Salm. typhimuriutn was greatly enhanced when those organisms were incubated in atmospheres of low oxygen tensions
... Oregano EO is active against moulds, especially aflatoxin-producing strains and foodborne bacteria [56,57]. Oregano EO exhibited a fungicidal effect due to a chemical composition rich in phenolic compounds, which can cause damage at the mycelial level [57]. ...
... Oregano EO is active against moulds, especially aflatoxin-producing strains and foodborne bacteria [56,57]. Oregano EO exhibited a fungicidal effect due to a chemical composition rich in phenolic compounds, which can cause damage at the mycelial level [57]. It has been demonstrated that oregano EO can be used to prevent infection with Fusarium spp. ...
This study aimed to investigate the antifungal and antimycotoxicogenic effect of binary and tertiary mixtures of Thymus vulgaris, Origanum sativum, and Coriandrum sativum essential oils (EOs), as well as emulsions based on EO mixtures, on fungi developed on wheat grains destined for the bakery industry. The chemical composition of the EO mixtures, the physical characteristics of the emulsions, and the influence of treatments on the proximate composition of wheat seeds were also studied. The methods used included the microbiological analysis of fungi developed on wheat seeds, the ELISA technique for determining the deoxynivalenol content (DON), gas chromatography coupled with mass spectrometry (GC-MS) to detect the chemical composition of the EOs, Zetasizer to analyse the particle sizes and their electric charge at the surface, and NIR analysis of the proximate composition of wheat. The chemical composition analysis revealed that thymol and o-cymene were the major components in the binary mixture of the EOs with thyme, linalool in the binary mixtures of the EOs with coriander and carvacrol, and o-cymene in the binary mixtures of the EOs with oregano. The results showed that, based on the zeta potential, the tertiary mixture ensured maximum emulsion stability, while the emulsion based on thyme and oregano was the less stable system. Regarding the antifungal and antimycotoxicogenic effect, the results showed that the highest inhibition potential on fungi was observed with the binary mixtures of the EOs based on thyme and oregano, and on deoxynivalenol (DON) when the binary emulsion based on the same EOs was applied to wheat seeds. The proximate composition of wheat seeds contaminated with DON showed an increase in protein content and mineral substances, and there were changes in the colour of the wheat seeds after treatment with the EOs. In conclusion, the results obtained in this study showed the possibility of using binary/tertiary mixtures of EOs and emulsions as healthy and environmentally friendly alternatives in the bakery industry.
... Since the beginning of the 1990s, some EOs or oil extracts from specific plants have been found to present efficacy in inhibiting various fungi and bacteria (Paster et al., 1990). In such studies, experiments have been performed directly on the pathogen (S. ...
... In such studies, experiments have been performed directly on the pathogen (S. Das et al., 2019;Jiang et al., 2020;Ju et al., 2019;Paster et al., 1990;Prakash et al., 2018;Reichling et al., 2005;Schnitzler et al., 2001;Sun et al., 2020), and also the antiviral activity of the corresponding substance has been then quantified (Astani et al., 2010;Koch et al., 2008;Loizzo et al., 2008;Nolkemper et al., 2006;Reichling, 2021;Reichling et al., 2009;Wani et al., 2021). Recently, these types of molecules have also been proposed as a coadjutant to SARS-CoV-2 treatments (da Silva et al., 2020;Nagoor Meeran et al., 2021;Omrani et al., 2021;Suvarna et al., 2021;Wani et al., 2021;Yadalam et al., 2021). ...
Until recently, food packaging has been used as a barrier to unfavorable environmental and microbial conditions, but new technologies are arising aimed at upgrading the protective nature of these materials. Cases of bacterial and viral transmission through food and surfaces have shown the vulnerabilities of the food packaging distribution systems over the years, creating awareness about new methods to prevent the proliferation of pathogens. This has been highlighted by safety concerns due to the COVID‐19 pandemic. This work reviews the state‐of‐the‐art biobased technologies tailored for antiviral applications on surfaces, focusing on packaging materials. A survey and selection tool of essential oils (EOs) and nanoparticles that have been proven effective in reducing the proliferation or transmission of viruses through surfaces is presented. Additionally, the use of essential oil formulations or nanoparticle‐functionalized biobased materials that can be deployed to prevent virus transmission through food produce and surfaces is reviewed, including environmental and safety concerns around the use of metal nanoparticles and EOs in packaging materials. Finally, an assessment of the available technologies, challenges, opportunities and the potential role of biobased antiviral surfaces in future viral outbreaks is presented. Encapsulation of essential oils intended for packaging films.
... The essential oil of Oregano acts as a barrier against the growth of Aspergillus niger and A.flaus at 400 mg/ml, while A. ochraceus is inhibited at 600 mg/ml. The germination of fungal spores is obstructed by 600 mg/ml of oregano oil and (apart from A. ochraceus) with 700 mg/ml of thyme oil (Paster et al. 1990). ...
... hirtum, in dilution 1/4000 or even 1/50000 there was a considerable decrease in bacterial growth rates. The same essential oil exhibits high levels of cytotoxicity against four permanent animal cell lines, including two derived from cancerous human growths (Paster et al 1990;Sivropoulou et al. 1996). ...
The Greek territory provides an ideal environment for growing plants and herbs, which are to be found in abundance, flourishing on mountain sides, where they grow naturally. Medicinal plants are considered as important factors in sustainable development, environmental protection, and public health. The aim of this chapter is to present comprehensive information about the diversity, ecological value, cultivation, and utilization of the economically important medicinal plants such as Salvia sp., Origanum sp., and Sideritis sp., in Greece, stressing their medical-environmental and economical values. The utilization of our natural wealth together with the conservation of biodiversity is issues of paramount importance. Valuable aides to these appear to be the medicinal plants which play a crucial role in both these sectors. Another important fact we should keep in mind is the potential use of medicinal plants and their unconventional applications in sustainable agriculture, enhanced by the selective and multiple biological properties of their essential oils. Numerous and valuable uses are more than possible as the diversity of medicinal plants presents new sustainable opportunities—financial and environmental—for agriculture, and this should be the motive to boost further studies concerning the cultivation of medicinal plants.
... З метою досягнення цих цілей нами вивчено дію натуральної кормової добавки в склад якої входять стандартизовані і стабілізовані ефірні компоненти, які володіють перетравною, бактерицидною та антиоксидантною функціями (Curtis et al., 1986;Paster et al., 1990;Lo´pez et al., 2005;Kwiatek, 2007;Lo´pez et al., 2007;Tunc et al.,2007;Upadhyay, 2010). ...
... Вона посилює сприйняття запаху та смаку корму, знижує наслідки стресу та захворювань (Bracey et al., 1998;Mayaud et al., 2008;Paster et al., 2006;Reichling et al., 2009); -ефірну олію розмарину, яка володіє антиоксидантними і протизапальними властивостями, регулює температуру тіла та знижує біль при запальних процесах (Halle et al., 1987;Bagamboula et al., 2004;Lo´pez et al., 2007); -екстракт перцю чілі покращує травлення, оптимізує конверсію корму, посилює секрецію шлункового соку і виділення травних ферментів, а також підвищує засвоєння поживних речовин (Mayaud et al., 2008;Reichling et al., 2009); -ефірну олію орегано, яка проявляє бактерицидні та антиоксидантні властивості, сприяє зниженню росту грибків, бактерій та патогенних паразитів в шлунковокишковому тракті. Під її впливом підвищується проникна здатність мембран бактерій завдяки чому змінюється кислотність внутріклітинного середовища бактеріальних клітин, пригнічує енергію синтезу бактеріальних клітини та інгібує вільні радикали (Curtis et al., 1986;Paster et al., 1990;Kwiatek, 2007;Tunc et al.,2007). ...
In order to increase the intensity of livestock development and obtain safe products such as meat and milk, it is of great importance to provide cows with qualitative feed and optimal maintenance. An important role is devoted to the animal health because it directly affects productivity. The use of poor quality feeds leads to animal health deteriorating, reduced productivity. Dis-balance of the gastrointestinal microbiota leads to poor food intake and clinical manifestations of disease. In order to increase feed efficiency and productivity indexes, were used extracts of essential oils contained in the feed additive "Activo". This supplement with its properties stimulates feed intake, digestion, has bactericidal and anti-stress properties with positive effect on animal health and productivity. The experiment revealed a positive effect of feed additive "Activo" on cows’ organism after calving and at the beginning of lactating. The influence of essential oils extracts contained in the feed additive "Activo" on the feed intake and digestion, milk production, protein and fat levels has been studied. There is a systematic dependence on feed intake increasing to milk yield. At the same time, indexes of quality such as fat and protein content were almost stable. According to the experimental results, it is possible to recommend milk producers to use "Activo" as part of cow feed with the aim to improve health and productivity.
... The essential oil of oregano inhibits completely the mycelial growth of Aspergillus niger and A. flaous at 400 mg/ml, while A. ochraceus is inhibited at 600 mg/ml. Fungal spore germination is inhibited by 600 mg/ml of origanum oil and (with the exception of A. ochraceus) with 700 mg/ml of thyme oil (Paster et al., 1990). Under aerobic conditions, the essential oil of oregano (250 mg/ml) inhibited to some extent the growth of Staphylococcus aureus and Salmonella typhimurium. ...
... hirtum is extremely bactericidal at 1/4000 dilution and even at dilutions as high as 1/50000 caused a considerable decrease in bacterial growth rates. The same essential oil also exhibits high levels of cytotoxicity against four permanent animal cell lines including two derived from human cancers (Paster et al., 1990;Sivropoulou et al., 1996). Carvacrol causes a total obstructing in the development of colonies of fungus Penicillium digitatum, Fusarium solani var. ...
Medicinal and aromatic plants represent a stable part of the natural biodiversity legacy of many countries in the world. The present review focuses on oregano (Origanum vulgare L.; family Lamiaceae), an endemic herb in Greece that constitutes one of the best known aromatic and medicinal plants originating in the Mediterranean region. In particular, oregano is an evergreen, rich in natural compounds perennial plant that received increased attention in the last years for a wide range of uses. Oregano dry leaves and inflorescences in mixture are used as human and animal food that is extremely rich in antioxidative properties. Additionally, its essential oil is rich in carvacrol, thymol, c-terpinene and p-cymene, and is used for a number of medicinal purposes, e.g. for inhibiting microbial and fungal toxin production as well as for the well-known anti-inflammatory, analgesic, antiarthritic, antiallergic, anticarcinogenic, antidiabetic, cardioprotective, gastroprotective, hepatoprotective, and neuroprotective properties. Due to its perfect quality and high essential oil concentration, Greek oregano (O. vulgare ssp. hirtum) is regarded among the best in the world gaining in popularity in the global markets for food industry applications. Consequently, oregano might be considered as an important low-input, environmental friendly commodity for extensive cultivation in Greece. The present review summarizes on the origin, the morphology, the ecology and the utilization of this plant. Despite the extensive literature available on the use of oregano biomass and essential oil, only few reports exist concerning the cultivation of this plant. Therefore, the present review is additionally focused on the cultivation practices and the importance of cultivation and utilization of Origanum vulgare L. in Greece and generally in the Mediterranean region in the near future, as it constitutes a plant species with high medical, economic and environmental value.
... In addition, Burt (2004) Salmonella tiphymirium and Pseudomonas aeruginosa. Burt (2004) noted that minimum TEO inhibitory concentrations generally range from 0.005 to 0.5 %. Paster et al. (1990) reported that TEO used at 500 µg/mL inhibited growth of Staphylococcus aureus and Salmonella tiphymirium, while Pseudomonas aeruginosa was not affected even at higher concentrations. Burt and Reinders (2003) and Paster et al. (1990) recorded inhibition diameters for Escherichia coli ranging from 24 to 25.7 mm when using diluted TEO. ...
... Paster et al. (1990) reported that TEO used at 500 µg/mL inhibited growth of Staphylococcus aureus and Salmonella tiphymirium, while Pseudomonas aeruginosa was not affected even at higher concentrations. Burt and Reinders (2003) and Paster et al. (1990) recorded inhibition diameters for Escherichia coli ranging from 24 to 25.7 mm when using diluted TEO. According to Calo et al. (2015) effectiveness of essential oils demonstrated in vitro should not be considered strictly true, due to food matrix complexity in which intrinsic and extrinsic factors interfere with activity of these compounds and must be confirmed by an in vivo assay. ...
This study aims to use thyme essential oil (TEO) as an antibacterial agent in raw milk intended for the production of farm cheese and to test its effect on bacteriological and sensory quality. Antibacterial activity of TEO was first tested in vitro on four strains of bacteria known for their pathogenicity such as Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium and Staphylococcus aureus and then in situ on the total mesophilic aerobic flora (TMAF) in raw milk used to produce farm cheese. All tested bacteria were very sensitive to TEO with a higher sensi t ivi ty for Escherichia coli, followed by Pseudomonas aeruginosa, then Staphylococcus aureus and finally Salmonella tiphymirium. In situ study showed that TEO has an effective effect on TMAF of raw milk. Monitoring bacteriological quality of TEO based farm cheese during 6 days of cold storage, revealed the effectiveness of TEO on TMAF, yeasts and moulds. Despite the good bacteriological quality of TEO-based farm cheese, the strong aroma characterizing this essential oil was not well appreciated by some tasters, which had a negative impact on the final score attributed to this cheese. Thyme essential oil can be used as an alternative solution to produce healthy farm cheese without needing heat treatment, while ensuring high nutritional value food product.
Keywords: Antibacterial effect, Farm cheese, Milk quality, Pathogenic bacteria, Thyme essential oil.
... The essential oil of oregano inhibits completely the mycelial growth of Aspergillus niger and A. flaous at 400 mg/ml, while A. ochraceus is inhibited at 600 mg/ml. Fungal spore germination is inhibited by 600 mg/ml of origanum oil and (with the exception of A. ochraceus) with 700 mg/ml of thyme oil (Paster et al., 1990). Under aerobic conditions, the essential oil of oregano (250 mg/ml) inhibited to some extent the growth of Staphylococcus aureus and Salmonella typhimurium. ...
... hirtum is extremely bactericidal at 1/4000 dilution and even at dilutions as high as 1/50000 caused a considerable decrease in bacterial growth rates. The same essential oil also exhibits high levels of cytotoxicity against four permanent animal cell lines including two derived from human cancers (Paster et al., 1990;Sivropoulou et al., 1996). Carvacrol causes a total obstructing in the development of colonies of fungus Penicillium digitatum, Fusarium solani var. ...
Medicinal and aromatic plants represent a stable part of the natural biodiversity legacy of many countries in the world. The present review focuses on oregano (Origanum vulgare L.; family Lamiaceae), an endemic herb in Greece that constitutes one of the best known aromatic and medicinal plants originating in the Mediterranean region. In particular, oregano is an evergreen, rich in natural compounds perennial plant that received increased attention in the last years for a wide range of uses. Oregano dry leaves and inflorescences in mixture are used as human and animal food that is extremely rich in antioxidative properties. Additionally, its essential oil is rich in carvacrol, thymol, c-terpinene and p-cymene, and is used for a number of medicinal purposes, e.g. for inhibiting microbial and fungal toxin production as well as for the well-known anti-inflammatory, analgesic, antiarthritic, antiallergic, anticarcinogenic, antidiabetic, cardioprotective, gastroprotective, hepatoprotective, and neuroprotective properties. Due to its perfect quality and high essential oil concentration, Greek oregano (O. vulgare ssp. hirtum) is regarded among the best in the world gaining in popularity in the global markets for food industry applications. Consequently, oregano might be considered as an important low-input, environmental friendly commodity for extensive cultivation in Greece. The present review summarizes on the origin, the morphology, the ecology and the utilization of this plant. Despite the extensive literature available on the use of oregano biomass and essential oil, only few reports exist concerning the cultivation of this plant. Therefore, the present review is additionally focused on the cultivation practices and the importance of cultivation and utilization of Origanum vulgare L. in Greece and generally in the Mediterranean region in the near future, as it constitutes a plant species with high medical, economic and environmental value.
... With the increasing use of chemicals, antibiotics many pathogens have developed resistance against them; hence there is immense need to develop new anti-agent with improved performance and wide applications. Certain plant extracts have shown antimicrobial properties against certain bacteria (Paster et al, 1990) [14] and have been studied to be utilized as agro chemical with favorable antimicrobial activity (Kim et al, 1996) [9] . The essential oils from the Myrtaceae family exhibit diverse biological activities like bacteriostatic, fungistatic and anti-inflammatory effects. ...
... With the increasing use of chemicals, antibiotics many pathogens have developed resistance against them; hence there is immense need to develop new anti-agent with improved performance and wide applications. Certain plant extracts have shown antimicrobial properties against certain bacteria (Paster et al, 1990) [14] and have been studied to be utilized as agro chemical with favorable antimicrobial activity (Kim et al, 1996) [9] . The essential oils from the Myrtaceae family exhibit diverse biological activities like bacteriostatic, fungistatic and anti-inflammatory effects. ...
Eucalyptus has been used as a medicinal plant from ages because of its various properties. The phytochemical content of Eucalyptus leaves was analyzed by soxhlet extraction of the dried leaves using methanol and acetone. Maximum amount of phytochemicals present in eucalyptus leaves were retained in methanolic extract. The methanolic extract contained quinones, saponins, carbohydrates, tannins, phenols, flavonoids & fat while in the acetonic extract quinones, flavonoids & fat was present. The quantitative analysis of methanolic extract revealed an appreciable amount of antioxidant activity assessed by DPPH scavenging activity expressed in terms of ascorbic acid i.e. IC50 value of 444.6, the phenolic content was found to be 11.41% while the total flavonoid content was 35.88%.
... Oregano oil is very active against molds especially aflatoxigenic strains and foodborne bacteria like Aspergillus niger, Aspergillus flavus, Aspergillus ochraceus, Staphylococcus aureus, Salmonella typhimurium, Campylohacter jejuni and Clostridiurn sporogenes (Paster et al., 1990). ...
In the last decades, consumers’ attention has been focused on natural food products without preservatives, because they believe that food could have a direct influence on their health. From the industrial point of view, these new consumers’ preferences involves technological changes and reorientation to natural raw materials, like plants. In order to reduce or remove the synthetic preservatives from food products, previous researches has emphasized on the importance of self-life prolongation by using natural products like oregano (Origanum vulgare, Hirtum ssp.) herb and oil. The following mini-review attempts to synthesize the importance of oregano in food preservation industry due to its rich chemical composition on bioactive compounds which could have antimicrobial effects.
... For our tests, P. aeriginosa, although inhibited by the oils of the parental species of Eucalyptus, it was resistant to the oil of the hybrid species. Similar results were found by other research which showed that gram-negative bacterium, and in particular P. aeriginosa, appears to be the least sensitive to the action of essential oils [32,33]. Additional research has demonstrated the biological activities of these oils, including [34], which points to a strong antibacterial impact of the EOs of E. woodwardii and E. torquate. ...
Eucalyptus torwood is a spontaneous hybrid of two species: Eucalyptus torquata and Eucalyptus woodwardii. Our work aims to study the essential oils of these three taxa, including yield, chemical composition and antimicrobial activities, with the aim of analyzing the effect of hybridization on these parameters. The essential oil yields were 2.6, 2.52 and 2.12% for E. torquata, E. woodwardii and E. torwood, respectively. All three oils showed the same α-pinene content (around 12%), but E. woodwardii was richer in aromandendrene than the other two eucalypts, which have higher torquatone contents. Also, E. torwood showed a specific richness in β-eudesmol and a lower percentage in 1,8-cineole. The antibacterial and antifungal activity was determined against six bacterial strains, the results obtained highlight that the essential oils tested showed antimicrobial activity against gram-positive bacteria to different degrees, while on gram- negative bacteria they showed resistance. The yeast Candida albicans was most sensitive to the three Eucalyptus essential oils. To clarify the antibacterial effect of the major phytocompounds, we employed computational methods, including ADME and molecular docking. Significant results were obtained, molecular docking simulations highlighted high binding score of four major abundant compounds towards targeted receptors (pdb: 2zcq and pdb: 1kzn).
... The antifungal properties of oregano essential oil have already been reported in regard to Fusarium spp. and other plant pathogenic fungi, such as Alternaria alternata, Botrytis cinerea, Macrophomina phaseolina, Penicillium spp., Phytophthora capsici, Rhizoctonia solani, and Sclerotinia sclerotiorum [50]. In the non-inoculated samples, the application of oregano essential oil favored the growth of Emmonsiellopsis coralliformis, Arthrobotrys amerospora, Pseudallescheria boydii, Byssochlamys zollerniae, and Puccinia amari, while it had a negative effect on Mortierella chlamydospora, Chrysosporium pseudomerdarium, Conioscypha minutispora, Phialemonium globosum, and Aspergillus chlamydosporus. ...
The destructive effects of Fusarium wilts are known to affect the production of many crops. The control of Fusarium oxysporum and other soilborne pathogens was mainly based on soil fumigation (methyl bromide), which has long been prohibited and, nowadays, is based on a limited number of available fungicides due to legislation restrictions on residue tolerances and environmental impacts. Alternatively, natural and environmentally safe compounds, such as essential oils, are being investigated for their efficacy in the control of soilborne diseases. The great fungicidal ability of the oregano essential oil components (carvacrol and thymol) has been reported to inhibit the germination and the mycelial development of several fungal species, including F. oxysporum. The aim of our study was to demonstrate how the metabarcoding approach can provide valuable information about the positive or negative impacts of two different doses of oregano essential oil on Fusarium oxysporum and other fungal species which were present in the studied soil samples through the amplification of the ITS1 and ITS2 regions, which were analyzed on a MiSeq platform. A higher dose of oregano essential oil decreased the abundance of F. oxysporum, along with other fungal species, but also had negative effects on Trichoderma evansii and Mortierella chlamydospora, species with possible fungicidal properties. Soil properties, essential oil properties, the fungal composition, and interactions between fungal species should be considered as factors influencing the effectiveness of essential oils as biological control agents for soilborne pathogens.
... Essential oils present in oregano are active against the growth of the fungi Aspergillus niger, Aspergillus flavus and Aspergillus ochraceus, as well as against the bacteria Campylobacter jejuni and Clostridium sporogenes (Paster et al. 1990(Paster et al. , 1995Shaaya et al. 1991) and Clostridium botulinum (Ismaiel 1988). The same property was found against Phytophthora citrophthora, Phoma tracheiphila (syn. ...
This book is part of the series 'Promoting the conservation and use of underutilized and neglected crops'. Volume 25. Engels was the series manager.
... P. aeruginosa had the lowest sensitivity to both essential oils (inhibition zone 19 ± 0.7 and 16 ± 1.0 mm for oil from non-disintegrated and disintegrated fruit, respectively). Low sensitivity of this Gram-negative bacterium to essential oils was reported in earlier studies (Dorman and Deans, 2000;Lis-Balchin et al., 1999;Omulokoli et al., 1997;Paster et al., 1990;Senatore et al., 2000;Wilkinson et al., 2003). This can be explained by the hydrophilicity of P. aeruginosa membrane's surface, through which only small and hydrophilic molecules can pass, unlike hydrophobic molecules (such as essential oils' components) that remain on the surface of the membrane (Nikaido, 1994). ...
... In general, all three EOs showed an inhibitory effect against the growth of the SSO of RTE chilli shrimp paste. This agrees with Paster et al. (1990) and Mardafkan et al. (2015) where they concluded that both Gram-positive and Gram-negative bacteria are sensitive to EOs. All the values from disc diffusion assay (DDA) were found to be significantly different (p < 0.05). ...
Ready-to-eat (RTE) chilli shrimp paste has a short shelf life; thus, chemical additives are usually added to extend it. However, certain additives have potential health implications. In this regard, plant essential oils (EOs) which exhibit antibacterial properties can be used as an alternative for extending the shelf life of RTE chilli shrimp paste. The present work intended to (1) establish the microbial profile of RTE chilli shrimp paste, (2) determine the antibacterial activities of black cumin, clove, and ginger EOs against the isolated specific spoilage organisms (SSO) of RTE chilli shrimp paste, and (3) determine their effect on the shelf life of RTE chilli shrimp paste. Biochemical tests and 16S rRNA gene sequencing were used to identify the SSO in RTE chilli shrimp paste. Disc diffusion assay was performed for antibacterial analysis of EOs. To monitor the shelf life of the paste, total plate count (TPC) and yeast and mould count (YMC) were carried out for five days. The results showed that the SSO of RTE chilli shrimp paste were dominated by Staphylococcus spp. followed by Klebsiella aerogenes and Enterobacter tabaci. EOs of black cumin, clove, and ginger showed inhibitory effects against the SSO with the highest inhibition by ginger EO of 27.50 ± 9.19 to 58.00 ± 7.21 mm. Application of ginger EO in RTE chilli shrimp paste showed a 3-log reduction of bacterial population and 4-log reduction for fungal population. It was concluded that ginger EO can be a highly potential candidate to be added into RTE chilli shrimp paste as a natural additive to extend its shelf life.
... Several scientists reported the inhibitory effect of clove and cinnamon oils on growth and aflatoxin production by A. flavus [248][249][250][251][252] and, in maize, cinnamon and clove oils effectively fought against aflatoxin formation by A. flavus for 10 days [250]. A. flavus, A. ochraceus, and A. niger's reaction to oregano oil was noted by Paster et al. [253,254], and it was described as efficient in suppressing fungi in wheat [254]. Palmarose oil proved to be active against 12 fungi, to which it appeared to range from being non-effective to inhibitory [255]. ...
Contamination of crops with phytopathogenic genera such as Fusarium, Aspergillus, Alternaria, and Penicillium usually results in mycotoxins in the stored crops or the final products (bread, beer, etc.). To reduce the damage and suppress the fungal growth, it is common to add antifungal substances during growth in the field or storage. Many of these antifungal substances are also harmful to human health and the reduction of their concentration would be of immense importance to food safety. Many eminent researchers are seeking a way to reduce the use of synthetic antifungal compounds and to implement more eco-friendly and healthier bioweapons against fungal proliferation and mycotoxin synthesis. This paper aims to address the recent advances in the effectiveness of biological antifungal compounds application against the aforementioned fungal genera and their species to enhance the protection of ecological and environmental systems involved in crop growing (water, soil, air) and to reduce fungicide contamination of food derived from these commodities.
... The inhibition of growth and aflatoxin production from A. flavus by Thymus oils and their active components has frequently been reported by [34]. In this manner, the extent of inhibition of fungal growth and mycotoxin production was dependent on the concentration of essential oils used [35]. ...
Comparison between the antimicrobial effects of three different essential oils; thyme, castor and jo-joba was studied against some microbial species. Results showed that thyme essential oil from Thymus capitatus plant exhibits strong antimicrobial activity than the other two types, so it was subjected to further studies. Thyme oil was analyzed by GC and GC/MS and seventeen compounds were identified and the major components were thymol (45.36%). We further investigated the effect of thyme oil on af-latoxin production from Aspergillusflavus and the expression levels of the genes responsible for its bi-osynthesis. Transcription of five aflatoxins biosyn-thesis were detected by reverse transcription-poly-merase reaction analysis which revealed that all the expected amplicons were observed, whereas the expression of the structural genes could not be detected and this revealed that no differences of aflatoxin gene expression occurred between the two strains; (untreated and treated with thymus oil). Results showed that DNA barcoding is used as a tool for identification and phylogenetic construction of Thy-mus species, so PCR rbcL amplification and DNA sequencing suggesting that rbcL is universal tool for this species. Conclusively, our study accomplished that it is applicable to use the thyme oil as a source of a natural antifungal and detoxification agent.
... Since we did not see a good result on P. expansum, there might be a chance where Thyme oil would react better on other strains of pathogens. A research using Thyme oil extract stated that there was a total inhibition of the mycelia growth on the food borne bacteria: Aspergillus niger and A. flavus (Paster et al., 1990). Hence, although our results on Thyme oil were not significant, the future for use of essential oil like Thyme oil in bio-control might look promising. ...
Apple fruits are usually stored after harvest. During cold storage losses of economic importance are produced by several post-harvest fungal pathogens. Pathogens modify the pH of their host tissue to ease for infection and disease development. The present study was intended to show the importance of pH modification for decay development on fruits of two commercial apple cultivars (Fuji and Elstar) caused by four fungal pathogens (Penicillium exapsum2020, Penicillium exapsum21525, Botrytis cinerea and Colletotrichum acutatum). Besides, it was intended to highlight the use of bio-control products as one of the management options against blue mold. The study pointed out that P. exapsum2020, P. exapsum21525 and B. cinerea acidified the host tissues by lowering the pH, where as C. acutatum experienced alkalinisation by raising the pH during decaying on both apple cultivars. Among the pathogens, B. cinerea was more virulent on both cultivars followed by P. exapsum2020, P. exapsum21525 and C. acutatum respectively. The enzyme activity of the pathogens in the infected apple tissues was examined using AZCL-Azurine-Crosslinked Polysaccharide plates using different substrates and variation was obtained. P. expansum2020 inoculated samples showed better enzyme reaction in all of the substrates except in Beta-Glucan. The strongest enzyme reaction was obtained in substrate Xyloglucan followed by Xylan on both apple cultivars while C. acutatum showed better enzyme reaction in the substrate Casein. In the experiment involving bio-control on the blue mold fungus, Bio-Save gave the highest effect by significantly decreasing the size of the fungal lesions on both apple cultivars.
... Several studies documented the use of EOs to reduce the incidence of necrotic enteritis in chickens and to control the proliferation of C. perfringes (Timbermont et al., 2010;Jerzsele et al., 2012;Yang et al., 2015). Also, several reports have been published about the antibacterial effects of Piper nigrum, Origanum vulgare, Syzygium aromaticum and Thymus vulgaris, and their components, thymol, carvacrol, and eugenol, against Clostridium species (Paster et al., 1990;Dorman and Deans, 2000;Mitsch et al., 2004). ...
... On the other hand, the maximum inhibition halo in the presence of oregano was measured for isolates grouped in Cluster XIII (2 cm), which showed similarity with B. simplex and in Cluster XII, affiliated with Paenibacillus sp. in the presence of clove (0.9 ± 0.2 cm). These data are in line with previous works which highlighted the inhibitory effect of EOs, and the concentration of EOs required for growth inhibition [60]. ...
In this study, the biocidal activity of two plant derivatives (oregano and cloves’ essential oils—EOs) was evaluated, as a potential innovative and eco-friendly cleaning method for canvas paintings. The object of the study was the oil painting on canvas entitled “Studio di nudo” (Giovanni Maria Mossa, 1921), showing stains caused by microorganisms. The research focused on: (1) isolation and identification of microorganisms associated with discolorations on the obverse and reverse sides of the canvas; (2) evaluation of biocidal activity of selected EOs against fungal and bacterial collections. The phylogenetic identification was conducted with both cultivation and molecular methods. The canvas was mainly colonized by Penicillium, Aspergillus, and Cephaloteca fungal genera and by bacteria of the Bacillus genus. To evaluate the biocidal effect of the EOs’ volatile components only, an antibiogram assay (agar disc diffusion method) and a customized assay (named the contactless test) were conducted. Tested EOs showed antimicrobial activity on fungi and bacteria. However, compared to cloves, oregano EO exhibited a better inhibition activity both in contact and contactless tests. The work is pioneering for the use of EOs’ volatile compounds against oil painting biodeteriogens, and gives insights into possible extended, innovative and eco-friendly cleaning methods for painting control procedures.
... These findings show that the phenolic extracts from plants may contain not only phenolics but also other compounds that could possess antimicrobial activities, and that, in effect, essential oil components can work synergistically. Paster et al. (1990), evaluating the antimycotic capacity of essential oil of oregano and clove against three strains of Aspergillus, indicated that the studied molds differed in their sensibility to tested extracts and found that A. flavus was sensitive to the essential oil of oregano. Zaika et al. (1983) found that little if any inhibition of growth and acid production by Lactobacillus plantarum and Pediococcus acidilactici was noted in the presence of 40 ppm oregano oil, whereas levels >200 ppm were bactericidal to both organisms; in addition, they reported that bacteria exposed to sub-lethal concentrations of oregano oil were able to overcome the inhibition and to develop resistance to the toxic effect of oregano oil or oregano. ...
... coli) and Gram-negative bacteria (S. aureus) [90]. Further, essential oils from oregano and thyme have been reported to inhibit the growth of moulds including Aspergillus niger and A. flaous [91]. Clove essential oils has been reported of remarkable inhibition against Botrytis cinerea (gray mold) [92]. ...
Essential oils and their chemical constituents have been reported with well documented antimicrobial effects against a range of bacterial, fungal and viral pathogens. By definition, essential oils are a complex mixture of volatile organic compounds which are synthesized naturally in different parts of the plant as part of plants secondary metabolism. The chemical composition of the essential oils is dominated by the presence of a range of compounds including phenolics, terpenoids, aldehydes, ketones, ethers, epoxides and many others inferring that essential oils must be effective against a wide range of pathogens. This review article mainly focuses on the antiviral potential of essential oils and their chemical constituents especially against influenza and coronaviruses. Essential oils have been screened against several pathogenic viruses, including influenza and other respiratory viral infections. The essential oils of cinnamon, bergamot, lemongrass, thyme, lavender have been reported to exert potent antiviral effects against influenza type A virus. The essential oil of Citrus reshni leaves has been shown to be effective against H5N1 virus. The essential oil of Lippia species at a concentration of 11.1 μg/mL has been shown to induce 100% inhibition of yellow fever virus in Vero cells. Essential oils and oleoresins have been shown through in vitro and in vivo experiments to induce antiviral effects against Coronavirus infectious bronchitis virus. A study reported 221 phytochemical compounds and essential oils to be effective against severe acute respiratory syndrome associated coronavirus (SARS-CoV) using a cell-based assay measuring SARS-CoV-induced cytopathogenic effect on Vero E6 cells. The main mechanism of antiviral effects of essential oils has been found to cause capsid disintegration and viral expansion which prevents the virus to infect host cells by adsorption via the capsid. Essential oils also inhibit hemagglutinin (an important membrane protein of various viruses) of certain viruses; this membrane protein allows the virus to enter the host cell. Many essential oils and their components could inhibit the late stages of viral life cycle by targeting the redox signalling pathway. Essential oils of Thymus vulgaris, cymbopogon citratus and Rosmarinus officinalis have been found to destabilize the Tat/TAR-RNA complex of HIV-1 virus, this complex being essential for HIV-1 replication. Being lipophilic in nature, essential oils can penetrate viral membranes easily leading to membrane disintegration. The current comprehensive review will facilitate researchers to find chemical entities from plant sources as possible inhibitory agents against various viruses.
... Antimicrobial-loaded edible films are systems that contain active molecules that demonstrate potent efficacy against different microbial agents (Paster et al., 1990;Vahedikia et al., 2019). For example, peptide-based antimicrobial compounds like nisin and lysozyme have been incorporated within biopolymeric films for enhanced antibacterial efficacy (Sun, Shao, Zhang, Wang, Dong, & Yu, 2019;Wang et al., 2018). ...
The current work is focused on the synthesis of tamarind kernel powder-based edible films that were loaded with the antimicrobial agent (geraniol). The prepared films were characterized for physical, optical, microstructural, molecular, barrier, and antimicrobial properties. The incorporation of geraniol resulted in the formation of rough-surfaced films, as observed from E-SEM micrographs. FTIR study demonstrated reduction in hydrogen bonding with the addition of geraniol. XRD analysis indicated a pre-dominant amorphous property of the films. However, the incorporation of geraniol in low concentrations promoted crystallite growth. WVTR, Young's modulus, and tensile strength exhibited a decreasing trend with the addition of geraniol. The percentage stress relaxation of the film increased with the increase in the loading concentration of geraniol. The geraniol-loaded films showed robust antimicrobial effectiveness against both Bacillus cereus and Escherichia coli. These results showed that the films have a high potential to be used in the development of antimicrobial packaging films for food applications.
... The lower TPC count for treatments in comparison to control might be attributed to the antibacterial activity of EOs (varying degrees) which gets influenced by the concentration to which oxygen is available. This might be due to the reason that when little oxygen was present, fewer oxidative changes could take place in the EOs and/or that cells obtaining energy via anaerobic metabolism are more sensitive to the toxic action of EOs (Paster et al., 1990). ...
The present study was aimed to develop Manihot esculenta and Carrageenan bio‐based composite active film functionalized with anise, caraway, and nutmeg essential oils (EOs) and to assess the shelf life of chicken nuggets wrapped with the developed film at refrigeration storage. Overall, the Minimum Inhibitory Concentration (MIC) values of the three EOs ranged from 0.4 to 0.8% v/v of which nutmeg EO was found most effective. Incorporation of EOs in the film resulted in significant (P ˂ 0.05) decrease in tensile strength and water activity while elongation at break was significantly (P ˂ 0.05) increased. No significant (P ˃ 0.05) changes in thickness and Water Vapor Transmission Rate (WVTR) were observed. Based on physicomechanical and sensory evaluation, films incorporated with 0.5, 1, and 1% concentration of anise, nutmeg, and caraway EO were selected. Chicken nuggets overwrapped with aforementioned films were stored aerobically at refrigeration temperature (4 ± 1 °C) to evaluate antimicrobial, antioxidant, and sensory characteristics. The result indicated that pH, peroxide, free fatty acid (FFA), and thiobarbituric acide (TBA) value of treatments were significantly (P ˂ 0.05) lower than controls however significantly (P < 0.05) higher DPPH activity was observed in all treatments. The total plate count, psychrophilic count and, yeast and mold count were also significantly (P ˂ 0.01) lower in treatment groups and were within the permissible limits. The treated samples were well acceptable during whole storage period of 15 days. The application of composite, active edible bio‐based film was found proficient in confining product quality attributes throughout storage.
Practical Application
The majority of films used for packaging of meat and meat products are derived from synthetic “plastic” materials. The demerits associated with plastics have eventually led to explore natural alternatives such as edible films. The composite‐active bio‐based films have a huge potential to be molded for specific film properties based on requirements of product‐specific packaging conditions.
... After this period, the number of these microorganisms remained stable in the mozzarella coated with zein film and oils blend (coated þ EO) and showed a significant decrease in the other mozzarellas, coated only with zein film and uncoated. The essential oils of garlic and thyme, used in this study, are known to have antimicrobial activity, acting on both fungi and bacteria (Benkeblia, 2004;Millezi et al., 2013;Paster et al., 1990;Sharma et al., 2018). Thus, the lower number of microorganisms present in the mozzarella coated with zein film containing essential oils up to the tenth day of storage may have been due to the antimicrobial activity of these oils. ...
Purpose
The main purpose of this paper was to evaluate the influence of the zein coating containing essential oils on the sensory characteristics of sodium-reduced mozzarellas.
Design/methodology/approach
Mozzarellas were prepared by dipping in brine containing 5, 10, 15 or 20% of NaCl (w/v) that correspond, respectively, to 25, 50, 75 and 100% of NaCl content used in industry. These salted mozzarellas and another one, unsalted, were coated by an edible zein film added with 3% of a mixture of thyme and garlic essential oils (1:1). They were subjected to sensory analysis in relation to salty taste and overall impression. The mozzarella without salt reduction (20% NaCl w/v), coated or uncoated with the edible film, was also subjected to the analysis of water loss and microbiological quality, in order to evaluate the impact of this film on product quality.
Findings
The zein coating added with oils did not compromise the sensory acceptance of the mozzarella prepared with up to 50% of salt reduction. Water loss and microbial growth were lower in zein-coated mozzarella than in uncoated mozzarella. These results showed that this film could be applied as natural additive, contributing to the microbiological and sensory characteristics of the mozzarella.
Originality/value
This paper contributes to reducing the lack of studies in relation to new technologies for food preservation and sodium reduction. In addition, the zein coating containing essential oils can be tested on other food categories.
... The essential oil inhibited the growth of the bacterial strains used in this study at different rates depending on the concentration and the type of tested organisms. These results are in agreement with Mohamed et al. (2016), Mardafkan et al. (2015) and Paster et al. (1990), who concluded that Gram positive and Gram negative organisms were both susceptible to the oil. The expressed antimicrobial activity was concentration dependent as higher concentrations of the respective oils elicited a corresponding maximal antimicrobial activity. ...
Dried seeds of Monodora myristica were obtained from Oba market in Edo State, ground into fine powder and stored in an air tight plastic container at room temperature until when used. Essential oils were extracted using steam distillation and characterised using the gas chromatography-mass spectroscopy (GC-MS) technique. Microbial isolates obtained from smoke dried fish samples purchased from Oba Market, Benin City, Edo State. Fish samples were put in perforated polythene bags kept in plastic baskets and stored for four (4) weeks. Identification and characterisation of isolates were carried out following standard microbiological procedures. The antimicrobial activity was determined using agar well diffusion method. Data obtained were subjected to a one-way analysis of variance. Significant means were separated using Duncan Multiple Range Test at 95% confidence level. The result showed that M. myristica oil contained twenty-five components which were mainly monoterpene hydrocarbons constituents consisting of limonene (17.6%), α-phellandrene (16.3%), α-pinene (12.2%), β-myrcene (11.2%), 3-Thujene and β-Linalool (7.3%). The oil showed bacteriocidal activity at minimum ihhibitory concentration/minimum bactericidal concentration (MIC/MBC) of 150 mg/mL against Staphylococcus epidermidis PM221, Micrococcus luteus NCTC 2665, Bacillus subtilis 6051-HGW and Pseudomonas aeruginosa AAU2 and fungicidal activity at MIC/minimum fungicidal concentration (MFC) of 300 mg/mL against Aspergillus flavus and Rhizopus species. In view of the aforementioned, the expressed antimicrobial activity is a demonstration of the efficacy of the oil against fish spoilage organism and use in the fishery industry.
... Bu güne kadar 1300'den fazla bitki türünün antimikrobiyal aktivite içeren bileşikleri bulundurduğu bilinmektedir ancak bunların çok az bir kısmı bilimsel olarak çalışılmıştır [17,21]. Daha önce yapılan çalışmalarda birçok bitki türünün uçucu yağ ve bitki ekstratlarının ¹Sorumlu yazar / Corresponding author: yusuf.bayar@ahievran.edu.tr ...
Z Bitki patojenlerinin kontrol edilmesinde kullanılan sentetik kimyasal ilaçların insan ve çevre sağlığı üzerine etkilerinin en alt düzeye indirilebilmesi için bitkisel ekstraktların kullanımı alternatif bir yöntem değerlendirilebilir. Bu çalışmayla; Vaccinium myrtillus (Yaban mersini) ve Inula viscosa (Yapışkan andız otu) bitkilerinin toprak üstü kısımlarından elde edilen methanol ekstraktının Monilinia fructigena (Honey in Whetze) üzerine antifungal aktivitesi in vitro koşullarda araştırılmıştır. Ekstraktların patojene karşı aktiviteleri agar petri yöntemi kullanılarak ile 1,33 mg/ml, 2 mg/ml ve 2,66 mg/ml dozların da belirlenmiştir. Ekstraktların patojenlerin miselyum gelişmeleri (MG) ve miselyum gelişim engellemeleri (MGE) hesaplanmıştır. Monilinia fructigena'nın miselyum gelişim engelleme üzerine I. viscosa ekstraktının 2,66 mg/ml dozda %74,42 V. myrtillus ekstraktının ise %57,92 oranında etkili olduğu belirlenmiştir. V. myrtillus ve I. viscosa bitki methanol ekstraktlarınında Monilinia fructigena'ya karşı in vitro koşullarda miselyum gelişimi üzerine etkili olduğu belirlenmiştir. Monilinia fructigena üzerine I. viscosa ekstraktının V. myrtillus ekstraktına göre daha etkili olduğu belirlenmiştir. Yürütülen çalışma, bitki patojenlerinin kontrolünde bitki ekstraktlarının kullanımının değerlenmesi için katkı sağlayacaktır. Anahtar Kelimeler: Antifungal etki, bitkisel ekstrakt, Vaccinium myrtillus, Inula viscosa AN EVALUATION ON THE CONTACT ACTIVITIES OF Vaccinium myrtillus and Inula viscosa PLANT EXTRACTS AGAINST Monilinia fructigena ABSTRACT The use of herbal extracts can be considered as an alternative method to minimize the effects of synthetic chemical pesticide used in the control of plant pathogens on human and environmental health. This study; Antifungal activity of methanol extract obtained from above ground parts of Vaccinium myrtillus (Blueberry) and Inula viscosa (False yellow head or Strong-Smelling Inula) plants on Monilinia fructigena (Honey in Whetze) was determined in vitro conditions. The pathogen activity of the extracts was determined by using agar petri method at doses of 1.33 mg/ml, 2 mg/ml and 2.66 mg/ml. Mycelial growth (MG) and mycelial growth inhibition (MGE) of pathogens of extracts were calculated. Monilinia fructigena on inhibition the development of mycelium; a dose 2.66 mg/ml dose, 74.42% of I. viscosa extract and 57.92% of I. myrtillus extract was determined to be effective. V. myrtillus and I. viscosa plant methanol extracts against Monilinia fructigena in vitro conditions were determined to be effective on the development of mycelium. Monilinia fructigena on I. viscosa extract was found to be more effective than V. myrtillus extract. The study, will contribute to the evaluation of the use of plant extracts in the control of plant pathogens.
... Another aspect of significant importance is the implications on human and animal health that involve A. flavus in reference to the presence of mycotoxins and to the damages that occur in immunologically compromised patients. In the last few decades, due to the resistance of the use of fungicides [26], different investigations have been oriented and promoted, involving the study of plant extracts as an alternative for their control [27][28][29][30][31][32]. ...
Aspergillus flavus is a filamentous, saprophytic fungus, whose colonization occurs mainly in cereal grains and oilseeds once harvested. Under certain conditions, it could produce mycotoxins called aflatoxins, known as powerful human liver carcinogens. The aim of the present study was to describe the antifungal activity of extracts of Peltophorum dubium, a species from northern Argentina (Oriental Chaco), against A. flavus. The antifungal activities of different collection sites are reported. The extracts exhibited a minimum inhibitory concentration of 125 µg/mL, and the differences between the treatments and the inoculum control were 11 mm of P. dubium A and 10 mm of P. dubium F in colony growth. Moreover, hyphae treated with the extracts stained blue with Evans blue showed alterations in the membrane and/or cell wall, allowing the dye income. Bio-guided fractionation, High Performance Liquid Chromatography diode array ultraviolet/visible (HPLC UV/VIS DAD), and Ultra-High Performance Liquid Chromatography Electrospray Ionization Mass Spectrometry (UPLC ESI-MS) analyses were conducted to characterize the extracts and their active fractions. The HPLC UV/VIS DAD analysis allowed the determination of the presence of flavonoids (flavonols and flavones), coumarins, terpenes, and steroids. UPLC ESI/MS analysis of active fractions revealed the presence of Kaempferol, Apigenin, Naringenin, Chrysin and Daidzein.
... It is generally considered that compounds produced naturally, rather than synthetically, will be biodegraded more easily and therefore be more environmentally acceptable. It is well established that the plant extracts have antimicrobial properties against bacteria, moulds and yeasts (Farag et al., 1989;Paster et al., 1990;Aureli et al., 1992;Pai and Platt, 1995). The mechanisms by which plant extracts control bacterial activity take many routs. ...
The present study was performed to investigate the antimicrobial activity of water, ethanol or chloroform extracts of Zingiber officinale , Ocimum basilicum leaves and flowers and Taraxacum officinale leaves and roots. These extracts were tested in vitro against bacteria (Escherichia coli, CGSC1885, Escherichia coli, CGSC2463 and Bacillus megaterium), fungi (Aspergillus flavus and Rhizopus nigricans) and Candida albicans by disc diffusion method. The effect of extracts on bacteria was studied using transmission electron microscopy. The results indicated that Zingiber officinale, Ocimum basilicum flowers extracts (water, ethanol, and chloroform), exhibited an antimicrobial activity against the tested bacterial species. While the ethanol extract of Ocimum basilicum leaves and chloroform extract of Taraxacum officinale leaves and roots exhibited antimicrobial activity against Bacillus megaterium only. On the other hand, all extracts of the used plants being had no effect on Aspergillus flavus, Rhizopus nigricans, and Candida albicans. The cells of the bacteria, treated and untreated with the plants extracts, were examined by transmission electron microscope(TEM), it was observed that the size and ultrastructure of the treated cells by Zingiber officinale and Ocimum basilicum flowers extracts were affected compared with the control treatment. The ethanol and water extracts of Zingiber officinale and Ocimum basilicum flowers extracts (ethanol, water, and chloroform) degraded the cell wall, plasma cell membrane disintegrate and the cytoplasme leaches out of the cell. The results of the phytochemical studied revealed the presence of polyphenols, flavonoids, and terpenoids in water, ethanol, or chloroform extracts of Zingiber officinale and Ocimum basilicum flowers extract in water and the concentration of this compounds differ according to the the solvnt.
... P. aeruginosa had the lowest sensitivity to both essential oils (inhibition zone 19 ± 0.7 and 16 ± 1.0 mm for oil from non-disintegrated and disintegrated fruit, respectively). Low sensitivity of this Gram-negative bacterium to essential oils was reported in earlier studies (Dorman and Deans, 2000;Lis-Balchin et al., 1999;Omulokoli et al., 1997;Paster et al., 1990;Senatore et al., 2000;Wilkinson et al., 2003). This can be explained by the hydrophilicity of P. aeruginosa membrane's surface, through which only small and hydrophilic molecules can pass, unlike hydrophobic molecules (such as essential oils' components) that remain on the surface of the membrane (Nikaido, 1994). ...
... P. aeruginosa (ATCC 27853) from gram negative bacteria appears to be the most sensitive bacteria to DHA. In the antibacterial susceptibility studies, many essential oils have been reported using against P. aeruginosa (Deans and Ritehie, 1987;Knobloch et al., 1989;Paster et al., 1990). These results have been substantially similar to those reported by other researchers for essential oils (Cosentino et al., 1999;Lambert et al., 2001;Karaman et al., 2003). ...
... Thyme volatile components were reported to have antioxidant activities comparable to those of known antioxidants such as α-tocopherol and butylated hydroxy toluene (BHT) (Lee, Umano, Shibamoto, & Lee, 2005). Thyme also has an antibacterial and antifungal activity (Paster et al., 1990). Addition of essential oil of thyme or thymol cause a significant decrease in the viable counts of Salmonella typhimurium (Juven, Kanner, Schved, & Weisslowicz, 1994). ...
Traditional foods represent the geographical distinct environment, resources and culture of people. According to the EUROFIR “Traditional food is a food of a specific feature or features, which distinguishes it clearly from other similar products of the same category in terms of the use of “traditional ingredients” (raw materials or primary products) or “traditional composition” or “traditional type of production and/or processing method”" (Tajkarimi et al., Trends Food Sci Technol 29:116–123, 2013). It can also be simply defined as products with specific raw materials, and/or with a recipe known for a long time, and/or with a specific process (Cayot, Food Chem 102:445–453, 2007). Food is a traditional symbol of Arab hospitality. Rosenberger (1999) wrote that even when people was suffering from scarcity of food and poverty, the traditional foods was always served to travelers and guests. Nowadays, special types of traditional cuisine are usually prepared to honor guests.
... Les HEs ont trouvé leur place dans l'aromathérapie, la pharmacie, la parfumerie, la cosmétique et la conservation des aliments. Leur utilisation est liée à leur large spectre d'activités biologiques [14], [5], [6], [13], [12], [4] La culture finale des souches a été effectuée sur de l'agar de dextrose de pomme de terre contenant les HEs à des proportions différentes. Ce milieu de culture a été préparé de la manière suivante: L'infusion de pomme de terre a été préparée en faisant bouillir 200 g de tranches de pommes de terre (lavées mais non pelées) dans un litre d'eau pendant 30 minutes à 1 heure. ...
Etude de l'activité antifongique des huiles essentielles de trois plantes aromatiques marocaines [ Study of the antifungal activity of essential oils of three moroccan aromatic plants ] ABSTRACT: The work we have done has been devoted to study the antifungal activity of essential oils of three moroccan aromatic and medicinal plants towards of three strains of dermatophytes responsible for superinfection of a contact dermatitis. The essential oils of the three plants studied: Thymus vulgaris, Mentha spicata and Citrus limonum, showed significant inhibitory activities on the three fungi tested. The antifungal activity is linked to inhibition of mycelial growth with particularly high concentrations of essential oils. Thus, the essential oil of Thymus vulgaris showed the greatest activity against dermatophytes compared to other oils. According to their sensitivity, the Trichophyton mentagrophytes species showed a high sensitivity to essential oils more than other dermatophytes.
... The essential oils of plants are widely used in many applications such in aromatherapy, pharmacy, perfumery, cosmetics and in food conservation, due to their wide spectrum of interesting biological activities 1,2,3,4 . Currently, nearly more than 3000 essential oils are known, about 300 of them are employed in various industry fields 5,6 . ...
In Algeria, the essential oils market is very modest and the development of this sector remains a problem to be solved. Artemisia herba alba (white wormwood) is aromatic and
medicinal plant rich in essential oils. It is in great demand by the national and international industrial sectors: pharmaceutical, food, cosmetics ...). The extraction by conventional
hydrodistillation gives low yield, a solution presented in this article is to make a pulsed electric field treatment to intensify the extraction of essential oils. The results indicate a good influence of the PEF on the efficiency of HE with reduction of the extraction time. The extraction yields obtained, for example being 2.05% for only 30 min of distillation after treatment with PEF (3kV / cm, n = 100) is 03 times more than a traditional extraction.
This result will undoubtedly have a major socio-economic impact.
... The essential oils of plants are widely used in many applications such in aromatherapy, pharmacy, perfumery, cosmetics and in food conservation, due to their wide spectrum of interesting biological activities 1,2,3,4 . Currently, nearly more than 3000 essential oils are known, about 300 of them are employed in various industry fields 5,6 . ...
This paper is aimed to investigate the application of Pulsed Electric Field (PEF) as a pretreatment step for the intensification of the essential oil extraction yield of Marrubium vulgar that is a local plant from Mascara, Algeria. PEF has been applied for this purpose to improve the permeabilization by electroporation of the biological membranes. The PEF treatment was optimized by using the experiments design methodology, by considering as input factors the voltage level, the pulses number and the distillation process duration. Obtained results have shown that (i) the electrical conductivity of the sample increases due to the enhancement of the mass transfer (ii) the extraction process is significantly improved because the amount of the PEF-treated essential oil has increased up to three times. Moreover, physicochemical analysis of the essential oil carried out before and after treatment has shown that almost all parameters were identified and recovered after treatment.
... The essential oils of plants are widely used in many applications such in aromatherapy, pharmacy, perfumery, cosmetics and in food conservation, due to their wide spectrum of interesting biological activities 1,2,3,4 . Currently, nearly more than 3000 essential oils are known, about 300 of them are employed in various industry fields 5,6 . ...
This paper is aimed to investigate the application of Pulsed Electric Field (PEF) as a pretreatment step for the intensification of the essential oil extraction yield of Marrubium vulgar that is a local plant from Mascara, Algeria. PEF has been applied for this purpose to improve the permeabilization by electroporation of the biological membranes. The PEF treatment was optimized by using the experiments design methodology, by considering as input factors the voltage level, the pulses number and the distillation process duration. Obtained results have shown that (i) the electrical conductivity of the sample increases due to the enhancement of the mass transfer (ii) the extraction process is significantly improved because the amount of the PEF-treated essential oil has increased up to three times. Moreover, physicochemical analysis of the essential oil carried out before and after treatment has shown that almost all parameters were identified and recovered after treatment.
Electrospinning is a versatile and simple method employed for the production of polymeric nanofibers, which have attracted considerable attention in the field of food processing and packaging because of their distinct characteristics. Nanofibers can be modified with bioactive chemicals, nanoparticles, and other additives to give them specialised features such as antibacterial activity, antioxidant properties, or enhanced barrier characteristics. Electrospinning polymeric nanofibers has the potential to significantly improve food processing and packaging by providing creative ways to boost food safety, quality, and shelf life. In order to fully harness the potential of this technology in the food business, it is crucial to continue conducting research and development, while also addressing obstacles pertaining to scalability and affordability.
The three botanical species: Mentha spicata, Thymus vulgaris, and Citrus limonum are a medicinal plants widely used in Morocco. The aromatic fractions of these plants offer new perspectives in herbal medicine through the development of new pharmaceutical preparations for therapeutic purposes. The essential oils (EOs) are extracted from dried plants, in the open air and away from light. The choice of these medicinal plants was made following an investigation and a statistical study conducted in various regions of Morocco. The results of physico-chemical analysis of the EOs oils are consistent with those of the AFNOR [1] standards. The analysis of their chemical composition was determined by gas chromatography-mass spectrometry (GC/MS). The antibacterial activity of these EOs was tested in two types of bacterial germs and the results for the in vitro activity show that these two germs has shown high sensitivity to these three EOs.
The in vitro activity of Cinnamomum cassia , Melaleuca alternifolia , and Cymbopogon citratus essential oils and antimycotics clotrimazole, fluconazole, and ketokonazole against T. mentagrophytes was evaluated by the disc-diffusion method. The essential oils were tested at 5, 10, 20, 30, 50, and 100 % concentration. It was found that Cymbopogon , commonly called lemongrass, and cinnamon show stable results independent of the concentration used, whereas the efficacy of tea tree oil, significantly decreases with the decreasing concentration. When comparing the efficacy of antimycotics the largest zone of inhibition was obtained with clotrimazole, while fluconazole proved to be ineffective. We found that cinnamon and lemongrass are more effective than the antimycotics that we have used. Our study confirmed that some essential oils can be used for the treatment of dermatophytoses caused by Trichophyton mentagrophytes and some of them are more effective than the commercial drugs.
Ekinezya (Echinacea purpurea) Asteraceae familyasından Kuzey Amerika orjinli, yaygın olarak kullanılan tıbbi bir bitkidir. Bu çalışma iç Anadolu koşullarında 35, 45, 55 ve 65 cm ekim sıklığının ekinezyada uçucu yağ oranı ve uçucu yağ bileşenleri üzerine etkisini belirlemek amacı ile yürütülmüştür. Araştırmada bitki boyu, bitki başına dal sayısı, bitki başına tabla sayısı, tabla verimi, kuru herba verimi, kuru yaprak verimi, uçucu yağ oranı ve uçucu yağ bileşenleri tespit edilmiştir. Ekim sıklıklarına göre bitki boyları 52-63 cm arasında değişmiş, en yüksek bitki boyu değeri 35 cm sıra arasından en düşük bitki boyu değeri ise 65 cm sıra arasından elde edilmiştir. Dal sayısı değerleri 4.2 – 6.5 adet/bitki arasında değişmiş, en düşük dal sayısı değerleri 35 cm ekim sıklığından, en yüksek değer ise 65 cm ekim sıklığından elde edilmiştir. Kuru yaprak verimleri 110 - 232 kg/da arasında değişmiş en yüksek kuru yaprak verim değeri 35 cm ekim sıklığından elde edilmiştir. Uçucu yağ oranları ise % 0.087 ile 0.164 arasında değişim göstermiş, en yüksek uçucu yağ oranı 65 cm ekim sıklığından elde edilmiştir. Araştırma sonuçları ekinezya bitkisinden yüksek uçucu yağ elde etmek için 65 cm arası ekim
sıklğında yetiştirilebileceğini göstermiştir.
Many studies have been conducted on the harmful effect of mycotoxins on human and animal health. However, other chemicals can also contribute to the toxicity of ingested foods, directly or indirectly (via animal products). Many synthetic chemicals that are used for field treatments of cereals, or applied during storage time to prolong the storage time and to insure the absence of fungal contamination, are proven to be harmful to human and animal health. In order to reduce the usage of such chemicals and to improve the already deteriorated ecosystems, scholars are dedicated to optimizing and commercializing a “greener” option not only for agronomic applications, but also for the food industry. Recent advances in the effectiveness of green preservatives aiming at the food industry will be described in this paper. The intention is to preserve not only the health-related aspects of food by applying green preservatives, but also to maintain the ecological aspect regarding the environment as much as possible.
The aim of the present work was the selection of aromatic plant essential oils (EOs) and/or ethanolic extracts (EEs) to prevent the late blowing defect (LBD) of cheese caused by Clostridium spp. EEs resulted more effective than EOs to inhibit dairy-borne Clostridium spp. in vitro. Savory, hyssop, lavender and tarragon EEs, which showed the lowest minimal inhibitory concentration against Clostridium tyrobutyricum, were selected to study the prevention of LBD caused by this bacterium in cheese.
Addition of savory and lavender EEs to cheese milk delayed LBD by 2 weeks, but at the end of ripening showed similar clostridial vegetative cells counts, spoilage symptoms and propionic, and butyric acids levels than blown control cheese. Tarragon EE, with the highest content in caffeic acid, also delayed LBD by 2 weeks, but it was more effective to inhibit Clostridium, since cheese with tarragon EE showed minor LBD symptoms, lower vegetative cells count and lower concentrations of propionic and butyric acids than the rest of cheeses made with EEs. This fact could be also attributable to the greater number of antimicrobial terpenes (1,8-cineole, 4-terpineol, α-terpineol, isoelemicin, methyl eugenol, and methyl trans-isoeugenol) detected in this cheese. This is the first report on the application of EEs to control C. tyrobutyricum in cheese.
The idea of this chapter is to study the effects of essential oils and plant nanoemulsions against some plant pathogens. Essential oils are aromatic compounds derived from various plant materials that are characterized by high fluctuations and complex composition. Due to their known antimicrobial and antifungal properties, these compounds are highly regarded for use in pharmaceutical, food, agricultural, and cosmetic products. Also, regarding the antifungal activity of these compounds, several studies have shown that essential oils can reproduce several types of fungi, such as Candida, Zygosaccharomyces, Pichia, Penicillium, and Debaryomyces, in food products. The use of essential oils to prevent the growth of fungi and plant pathogens has been on the rise for many years, but in general, very little research has been done on nanoemulsions of essential oils. When converted into emulsions, plant materials and essential oils do not have enough solubility to penetrate plant tissues, and these problems are solved by converting this structure into a nanoemulsion. In general, it can be said that nanoemulsions of vegetable oils that can be extracted from various native plants around the world can increase the shelf life of fruits and nutrients and prevent diseases such as soft rot without damaging the fruit's texture or changing its taste.
Numerous studies indicate that the efficiency of microwave extraction, a popular method for extracting essential oil, needs to be improved. In this study, we used fennel (Foeniculum vulgare) as the focused species, extracted its essential oil using three methods, including traditional hydrodistillation (HD), single‐cooled microwave extraction (SCME) and dual‐cooled microwave extraction (DCME), and then tested the chemical composition and antibacterial activity of the essential oils. The optimum parameters of DCME were liquid‐solid ratio 5.6 mL/g, extraction time 27 min and irradiation power 600 W. The yield of fennel essential oil raised to 1.172%. The composition of essential oils obtained by both SCME and DCME was obviously different from that obtained by HD, such as higher monoterpene hydrocarbons in SCME and higher oxygenated monoterpenes in DCME. Furthermore, Salmonella Typhimurium and Escherichia coli were the most sensitive to fennel essential oil, followed by Staphylococcus aureus and Listeria monocytogenes. The activity of essential oil from different methods against four bacteria strains was similar. Our founding revealed that the improved microwave extraction greatly raised the yield of fennel essential oil, retained its fragrance and antibacterial activity. Overall, this study provides a theoretical basis for the separation and application of essential oils from natural aromatic plants. Dual‐cooled microwave extraction for fennel essential oil was proposed. The proposed method was highlighted with high yield and less thermal reaction. The method retained fragrance and strong antibacterial activity of the essential oil.
Background and Objective: Ras cheese is one of the important dairy products that are consumed in great quantities. But this cheese is vulnerable to the growth of fungi during ripening and selling until consumption. Therefore, research aimed to detect fungi contaminating Ras cheese and try to resist them. Materials and Methods: The effect of various concentrations (0.25, 0.5, 1, 2 and 3%) of essential oils emulsions of clove ( Syzygium aromaticum ), thyme ( Thymus vulgaris ) and peppermint ( Mentha piperita ) severally on the mycelial growth of the isolated fungi as compared to the control sample was tested in vitro. Results: The results indicated that many fungal species belonging to the genera Aspergillus , Mucor , Eurotium and Mortierella were isolated from the infected Ras cheese. Ochratoxin A was found in two samples whereas recorded the highest level in sample number 1 (2.1 μg kg1). Aflatoxin M1 was found in few levels ranged between 0.012 and 0.360 μg kg1in cheese samples, while aflatoxin B1 and B2 weren't detected in all samples. Clove essential oil emulsion completely inhibited the growth of all tested fungi at the concentration of 0.5%, followed by thyme essential oil emulsion which inhibited the fungal growth of all fungi at the concentration of 1%, while peppermint essential oil emulsion was less effective. Conclusion: The research recommends that clove and thyme essential oils emulsions can be used to resist the fungi of Ras cheese. Also, suggests that more research could be done on these essential oils emulsions to produce safe foods free of fungi.
The aim of the present study is direct to evaluate the impacts of mint oil (1% and 2%) on the microbiological, chemical and sensory characteristics of Tilapia (Oreochromis niloticus) fillets to extending their shelf life at 4±1 ْ C. Fresh fish weighting about 250-275 g. was eviscerated, washed and filleted, then the fish fillets were immersed in mint oil solution [zero (control); 1% and 2%] stored at 4±1 ْ C. The storage samples were examined periodically for microbiological; chemical and sensory properties. The results indicated that total bacterial count, total psychrophillic bacteria, total mould, Enterococci sp, Staphylococci sp and Bacillus cereus were 2.7x10 4 , 2.2 x10 4 , 1.0x10, 4.8x10 2 , 5.6 x10 2 and 3.8x10 2 cfu/g, respectively. Moreover, the results showed that the chemical quality properties of fresh tilapia fillets such as pH, TVBN and TBA were 6.54, 8.48 mg.N/100g and 0.014 OD (Optical Density). The result showed that storage at 4˚C±1 considerably increased the total microbial counts in control samples which reached around 10 7 cfu/g (rejected) after 6 days. However, the total microbial count of treated samples with 1 and 2% Mint oil reached around 10 7 cfu/g after 10 days. Furthermore, mint oil solution caused decreasing in the count pathogenic bacteria Enterococci sp, Staphylococci sp and Bacillus cereus initially and during the cold storage period. The result of chemical analyses of treated samples with 0 (control); 1% and 2% mint oil showed that the pH value, TVBN and TBA were increased with Efficiency of mint oil (Mentha piperita) for prolonging the shelf-life of tilapia (Oreochromis niloticus) fillets 338 increasing the cold storage period. Sensory evaluation results showed that the overall-acceptability at zero time were 98.60; 94.60 and 93.0% for control; and treated with 1% and 2% mint oil, respectively. During cold storage period a significant decrement in the appearance; odor; texture and overall acceptability was recorded for all treatments under investigation as the storage period increase which the panelists rejected the samples at 6th; 10th and 10th for control; fillets immersed in 1% mint oil and fillets immersed in 2% mint oil, respectively during cold storage. Thus, mint oil can be used as a natural antimicrobial preservative and the proper good concentration was 1% mint oil which had good sensory properties and extended the shelf-life of tilabia (Oreochromis niloticus) fillets to 10 days as compared with 6 days for the control samples at cold storage (4±1 ºc).
Food packaging is a multidisciplinary area that encompasses food science and engineering, microbiology, as well as chemistry, and ignited tremendous interest in maintaining the freshness and quality of foods and their raw materials from oxidation and microbial spoilage. With the advances in the packaging industry, they could be engineered as easy-to-open, resealable, active, as well as intelligent with the incorporation of sensory elements while offering desired barrier properties against oxygen and water vapor. In this regard, the use of the electrospinning approach allows producing nanofibrous packaging materials with large surface-to-volume ratios and enables the higher loading of active agents into packaging materials. Electrospun packaging materials have been produced from various polymers (i.e., synthetic and natural) and their (nano)composites, and were mainly exploited for the encapsulation of active agents for their use as active food packaging materials. The electrospinning process was also used for the deposition of electrospun fibers on films to enhance their performance (e.g., as reinforcement material, or to enhance barrier properties). They could be even engineered to provide nutraceuticals to food, or antioxidant, antimicrobial or antifungal protection to the packaged food. In this article, first, introductory descriptions of food packaging, barrier properties, and electrospinning are given. Afterward, active and intelligent food packaging materials are briefly discussed, and the use of electrospinning for the fabrication of active food packaging materials is elaborated. Particular interest has been given to the polymer-type used in the production of electrospun fibers and active properties of the resultant packaging materials (e.g., antioxidant, antibacterial, antifungal). Finally, this review paper concludes with a summary and future outlook towards the development of electrospun food packaging materials.
L'Algérie est un pays riche en plantes aromatiques dont plusieurs sont endémiques. Parmi ces plantes figure l’origan (famille des Lamiacées). Les huiles essentielles et les extraits d'espèces d'origan sont largement utilisés dans l'industrie pharmaceutique, cosmétique et à la préservation de plusieurs produits alimentaires. Le présent travail, consiste à l’étude de l’espèce Origanum vulgare L. poussant à l’état spontané dans la région de Guelma (Est algérien). L’enquête ethnobotanique a permis de décrire les différentes utilisations de la plante, notamment son utilisation comme remède contre plusieurs maladies dont le syndrome grippal qui occupe la première place. L’étude morpho-anatomique a permis de confirmer l’identité botanique de l’espèce et de dégager les caractères distinctifs de l'anatomie d’origan. L’extraction de l’huile essentielle et son analyse par chromatographie en phase gazeuse couplée à la spectrométrie de masse (CPG/ SM) a révélé la prédominance du thymol (32.85%). L’étude de l’activité anti-radicalaire par le test du DPPH a montré que l’huile essentielle possède une activité antioxydante modérée (IC50 = 1,28 ± 0,07 mg / ml). L’huile essentielle a été testée sur la reproduction et la mortalité de la mite de farine Ephestia kuehniella. Elle provoque le prolongement de la période de pré-oviposition et la réduction de la période de dépôt des œufs et la fécondité. Les souches bactériennes testées se sont avérées sensibles à l’huile essentielle étudiée qui a généré une activité antibactérienne dont les zones d’inhibition ont été comprises entre 9,8 mm et 37,7mm et des concentrations minimales inhibitrices (CMIs) allant de 0,314 à 5,025 mg/ml.
Mycotoxin production is favored by high humidity and high water activity (aw). To control mycotoxin formation on the basis of moisture, the moisture content must be maintained below a certain critical level for each commodity. Aflatoxin production is favored by temperatures of 25 to 30°C, whereas below 8 to 10°C, aflatoxin production can occur, but the amounts produced are less and the time required for production is longer. Cycling or changing temperature may or may not increase aflatoxin production, depending on the temperatures, mold species and substrates involved. Other mycotoxic molds respond to temperature differently than the aspergilli. Species of Penicillium, Fusarium and Cladosporium are capable of growing at temperatures below 5°C, and some even just below freezing. Penicillium spp. can produce patulin, penicillic acid and ochratoxin at temperatures from 0 to 31°C, whereas Aspergillus ochraceus does not produce ochratoxin or penicillic acid below 12°C. Penitrem production by Penicillium crusto...
The essential oils of six wild Israeli species of the Labiatae family were studied. The main components in the oils of Majorana syriaca, Coridothymus capitatus, Satureja thymbra, Salvia fruticosa, Salvia dominica and Micromeria fruticosa were identified. Two phenolic chemotypes, one containing thymol, the other one carvacrol, were found in Majorana syriaca and Coridothymus capitatus. The hydrodistilled oils were analyzed by means of GLC and GC-MS. Identification of individual compounds isolated from the oils by fractional distillation and preparative GC was carried out by IR spectroscopy.
Of 21 food flavoring compounds tested against 39–40 organisms, 10 were ineffective at 1,000 ppm or 10 mM either at pH 6 or 8 and by either surface plating or in broth. The 11 effective compounds were d- and l-carvone, diacetyl, ethyl vanillin, eugenol, maltol, menthol, phenylacetic acid, phenylacetal-dehyde, 2,3-pentanedione and vanillin; with diacetyl and eugenol being the most effective. All were more effective at pH 6 than at pH 8. With the exception of maltol and phenylacetic acid, each was generally more effective against fungi than bacteria with the lactic acid bacteria being the most resistant. At pH 5.5 and 5°C, diacetyl was inhibitory to Pseudomonas fluorescens and P. geniculata at < 10 ppm. The findings suggest that compounds used in acid foods, ostensibly as flavoring agents, may exert antimicrobial effects when considered in context with all parameters of growth.
Thymol concentrations ≥ 500 μg/ml completely inhibited the growth of Aspergillus parasiticus, while lower concentrations of the flavor compound produced either partial or transitory growth inhibition. Aflatoxin production was inhibited to a degree ≤ that of growth.
Volatile compounds produced by apple fruits (Malus domestica, Borkh.) were separated and estimated by gas chromatography. Procedures were devised for estimation of compounds in air surrounding whole apples and discs of apple tissue, and in apple juice. Concentrations of volatiles in air passing over apples were influenced by tissue permeability, concentrations in peel or cortex, and the extent of enzymic hydrolysis of esters passing through the peel. the complexity of these effects prevents assessment of the importance of compounds in apple flavour based on their concentrations around whole fruit. the ratios of concentrations established in air around cortical discs to concentrations in juice were similar to air/water partition coefficients observed for standard compounds. Measurement of concentrations above cortical discs is simple and sensitive and can be related to flavour, through the olfactory threshold concentrations of the compounds detected.
The effects of 13 dried spices added to growth media at concentrations ranging from 0.l–1.0% were studied with respect to their bactericidal activity against Vibrio parahaemolyticus. Rates of growth of V. parahaernolyticus in culture media containing essential oils of oregano, thyme, and sassafras and in media containing citric, ascorbic, and malic acids were determined. Survival of the organism in tomato sauce adjusted to pH 4.4–6.5 and incubated at 10, 22 and 35°C were examined. Dried oregano and thyme were highly toxic to V. parahaemolyticus when present in growth media at a concentration of 0.5%. Essential oils of oregano, thyme, and sassafras were bactericidal at a 100 μg/ml level. Growth curves were similar in media adjusted to identical pH values, regardless of whether citric, ascorbic or malic acid was used to attain these values. No viable V. parahaemolyticus were detected in inoculated tomato sauce adjusted to pH 4.4 and held 24 hr at 10 and 22°C or after 4 hr at 35°C. After 24 hr, only a slight reduction in viable cell count was noted in tomato sauce adjusted to pH 5.6-6.5.
Fifty plant essential oils were examined for their antibacterial properties against 25 genera of bacteria. Four concentrations of each oil were tested using an agar diffusion technique. The ten most inhibitory oils were thyme, cinnamon, bay, clove, almond (bitter), lovage, pimento, marjoram, angelica and nutmeg. The most comprehensively inhibitory extracts were angelica (against 25 genera), bay (24), cinnamon (23), clove (23), thyme (23), almond (bitter) (22), marjoram (22), pimento (22), geranium (21) and lovage (20).
The inhibitory effects of various concentrations of thyme, mint, bay leaves and their alcohol extracts were tested on the growth of three food poisoning bacteria, Salmonella typhimurium, Staphylococcus aureus and Vibrio parahaemolyticus. In each spice medium, S. typhimurium displayed the lowest sensitivity Thyme, which inhibited the growth of S. aureus at a level of 0.05% was the most inhibitory of the three spices studied. Bay leaves were found to be the least active spice of which 0.5% concentration was necessary for the growth inhibition of S. aureus. In each growth medium containing spice extracts, V. parahaemolyticus was found to be the most sensitive bacteria; growth was inhibited by the addition of 1000, 5000 and 6000 ppm of thyme, bay leaves and mint, respectively.
Determination of the minimum inhibitory concen-trations (MIC) of 212 common soap fragrance raw materials demonstrated that
the paper disc-petri plate technique does not reflect the relative anti-microbial activity of these materials. Commonly used
soap bacteriostats were shown to be 100 to 1000 times more effective than the most active fragrance materials. Of 521 fragrance
materials initially screened by the petri plate method, 44% were inhibitory against one of the three test organisms, and 15%
were effective against all three(Staphylococcus aureus, Escherichia coli, Candida albicans). Of a selected number (212) of these positive materials, subsequently screened against a lipophilic diphtheroid organism(Corynebacterium sp.), 64 materials (30%) were positive against all four test organisms. However, only nine materials (4%) had a MIC as low
as 50 ppm compared to the common soap bacteriostat TCC, which had a MIC of 0.08 ppm (vs.S. aureus). In hand-degerming tests, no reduction of bacterial counts was obtained with a soap containing the most active fragrance materials.
These results demonstrate that creation of a practical antimicrobial soap fragrance does not appear to be possible.
The inhibitory effects of 10 selected Turkish spices, oregano essential oil, thymol and carvacrol towards growth of 9 foodborne fungi were investigated in culture media with pH 3.5 and 5.5. The antifungal effects of sodium chloride, sorbic acid and sodium benzoate and the combined use of oregano with sodium chloride were also tested under the same conditions for comparison. Of the spices tested, only sodium chloride were also tested under the same conditions for comparison. Of the spices tested, only oregano at 1.0, 1.5, 2.0% (w/v) levels showed effect on all fungi. 8% (w/v) sodium chloride was less effective than oregano. Oregano essential oil, thymol or carvacrol at concentrations of 0.025% and 0.05% completely inhibited the growth of all fungi, showing greater inhibition than sorbic acid at the same concentrations. The combined use of oregano and sodium chloride exhibited a synergistic antifungal effect.
This study compared the survival of three-strain mixtures (ca. 10(7) CFU ml(-1) each) of Salmonella typhimurium DT104, Listeria monocytogenes, and Escherichia coli O157:H7 in pasteurized and unpasteurized preservative-free apple cider (pH 3.3-3.5) during storage at 4 and 10 degrees C for up to 21 days. S. typhimurium DT104 populations decreased by <4.5 log10 CFU ml(-1) during 14 days storage at 4 and 10 degrees C in pasteurized cider, and by > or =5.5 log10 CFU ml(-1) during 14 days in unpasteurized cider stored at these temperatures. However, after 7 days at 4 degrees C, the S. typhimurium DT104 populations had decreased by only about 2.5 log10 CFU ml(-1) in both pasteurized and unpasteurized cider. Listeria monocytogenes populations decreased below the plating detection limit (10 CFU ml(-1)) within 2 days under all conditions tested. Survival of E. coli O157:H7 was similar to that of S. typhimurium DT104 in pasteurized cider at both 4 and 10 degrees C over the 21-days storage period, but E. coli O157:H7 survived better (ca. 5.0 log10 CFU ml(-1) decrease) than S. typhimurium DT104 (> 7.0 log10 CFU ml(-1) decrease) after 14 days at 4 degrees C in unpasteurized cider. In related experiments, when incubated in simulated gastric fluid (pH 1.5) at 37 degrees C, S. typhimurium DT104 and L. monocytogenes were eliminated (5.5-6.0 log10 CFU ml(-1) decrease) within 5 and 30 min, respectively, whereas E. coli O157:H7 concentrations decreased only 1.60-2.80 log10 CFU ml(-1) within 2 h.