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Antifungal activity of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) essential oils

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Abstract

The objective of this work was to study the effect of the essential oils of lemon (Citrus lemon L.), mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) on the growth of moulds commonly associated with food spoilage: Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum and Penicillium verrucosum, using the agar dilution method. All the oils showed antifungal activity against all the moulds. Orange essential oil was the most effective against A. niger, mandarin essential oil was most effective at reducing the growth of Aspergillus flavus while grapefruit was the best inhibitor of the moulds P. chrysogenum and P. verrucosum. Citrus essential oils could be considered suitable alternatives to chemical additives for use in the food industry.

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... [54] Other studies have corroborated the anti-bacterial activity of lemon essential oil against P. aeruginosa, Lactobacillus curvatus, E. ammnigenus, Mycobacterium smegmatis, Micrococcus luteus, Proteus vulgaris, Enterobacter gergoviae, S. aureus, S. xylosus, S. carnosus, Listeria monocytogenes and L. sakei. [55,56] Like lemon, bergamot essential oil has shown effective antibacterial activity against Campylobacter jejuni, and E. coli O157 and linalool a major component of the bergamot essential oil confirmed its anti-bacterial activity by inhibiting the growth of S. aureus and L. monocytogenes. [57] As expected, a different study has also reported that citrus orange essential oil can inhibit the growth of E. coli O457: H7 and Salmonella spp. ...
... Growth inhibition [67,68,74] C. [55,56,63] Antiviral Effect ...
... [61,63] As reported by several studies, different species of fungi including Aspergillus flavus, A. fumigatus, A. Niger, Alternaria alternata, cladosporium herbarum, curvularia lunata, Fusarium oxysporum, helminthosporum oryzae, Penicillium chrysogenum, penicillium overrucosum and trichoderma viride were susceptible to C. sinensis essential oil. [55,86,87] Citrus aurantium L. essential oil has reportedly shown significant inhibition against the growth of Aspergillus Niger, A. flavus, A. nidulans, A. fusarium graminearum, F. oxyporum, C. albicans, and Alternaria alternate.- [61,62,88,89] C. reticulata essential oil also showed antifungal properties by inhibiting the growth of Aspergillus flavus and it was found to cause 40% growth inhibition [93] ( Table 2). ...
Article
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Citrus essential oil (CEO) is obtained from the fruit of Genus Citrus, a flowering plant shrub in the family of the Rutaceae (Eremocitrus or Microcitrus) and extensively used in food, chemical industry, and traditional medicinal treatment owing to its pleasant aroma, antioxidant, and antiseptic properties. This review presents a botanical description, distribution, traditional uses, chemical composition, bioactive components, and the therapeutic uses as well as toxicological effects of the CEO. The objective was achieved via a comprehensive literature search of electronic databases such as Science Direct, PubMed, Web of Science, Wiley, ACS, Springer, Taylor and Francis, Google Scholar, SCOPUS, conference proceedings, thesis, and books until 2022 for publications. Citrus essential oils and their constituents are extracted and isolated either from the fruit peels, seeds, leaves, or flowers of the citrus plants. A comparative study of the sources of CEO confirmed its origin, ethnopharmacological and therapeutic uses. Over 2000 secondary metabolites have been isolated, with the main active constituents: being terpenes, monoterpenes, sesquiterpenes, and diterpenes. A comprehensive literature review revealed vast therapeutic benefits of CEO. Incomplete data report on in vitro and in vivo trials especially, on dosage, positive and negative control groups, intervention time, toxicity studies, phytochemical profiling, and clinical trials seem to be a knowledge gap.
... These concern use of EOs not only as alternative antibiotics in the medical field [12,[55][56][57][58][59][60], but particularly as food additives. The latter usage, that may also involve EOs extracted from other plants which are not considered in this article, aims at improving the quality of a wide array of food products with reference to both possible contamination with human pathogens and preservation of organoleptic properties after inhibition of deteriorating microbial agents [47,50,56,[61][62][63][64][65][66]. Of course, the latter is a priority aspect in the case of citrus fruits, which generally need to overcome prolonged postharvest periods before undergoing either fresh consumption or industrial transformation. ...
... Inhibitory effects have also been documented against other fungi, such as Aspergillus spp. [55,63,78,82,85,[93][94][95]97,101,103,104], which may affect citrus quality as mycotoxin producers [105,106]. The gray mold agent Botrytis cinerea, also recently affirmed as an emergent citrus postharvest pathogen [107], proved to be sensitive to lemon essential oil, which completely inhibits in vitro growth at concentrations of 17 µL mL −1 [83], or 0.016% [108]. ...
Article
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Citrus essential oils (EOs) are widely used as flavoring agents in food, pharmaceutical, cosmetical and chemical industries. For this reason, their demand is constantly increasing all over the world. Besides industrial applications, the abundance of EOs in the epicarp is particularly relevant for the quality of citrus fruit. In fact, these compounds represent a natural protection against postharvest deteriorations due to their remarkable antimicrobial, insecticidal and antioxidant activities. Several factors, including genotype, climatic conditions and cultural practices, can influence the assortment and accumulation of EOs in citrus peels. This review is focused on factors influencing variation of the EOs’ composition during ripening and on the implications on postharvest quality of the fruit.
... Consequently, the mandarin essential oil has potential antibacterial effect against S. aureus, one of the foremost foodborne pathogens around the world, that showed strong tolerance to low temperature (4 • C and− 20 • C), at which food is typically stored (Qiao, Zhu et al., 2020). Meanwhile, this oil had little growth inhibition effect on other bacteria commonly used in the food industry like Lactobacillus curvatus, L. sakei, Staphylococcus carnosus, and S. xylosus or related to food spoilage as Enterobacter gergoviae and E. amnigenus (Viuda-Martos, Ruiz-Navajas et al., 2008). Regarding its antifungal effect, it exhibited a potential inhibitory effect against several moulds commonly associated with food spoilage (Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, and Penicillium verrucosum) (Viuda-Martos, Ruiz-Navajas et al., 2008) and is regarded as a natural antimicrobial for food preservation. ...
... Meanwhile, this oil had little growth inhibition effect on other bacteria commonly used in the food industry like Lactobacillus curvatus, L. sakei, Staphylococcus carnosus, and S. xylosus or related to food spoilage as Enterobacter gergoviae and E. amnigenus (Viuda-Martos, Ruiz-Navajas et al., 2008). Regarding its antifungal effect, it exhibited a potential inhibitory effect against several moulds commonly associated with food spoilage (Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, and Penicillium verrucosum) (Viuda-Martos, Ruiz-Navajas et al., 2008) and is regarded as a natural antimicrobial for food preservation. This activity is correlated to the presence of limonene (reaching 78.89% in the oil) in C. reticulata essential oil (Espina, Somolinos et al., 2011;Simas, de Amorim et al., 2017;Song, Liu et al., 2020). ...
Article
Fruits are regarded as the richest dietary sources of polyphenols, carotenoids, terpenoids, and limonoids, making them highly desired prospects for the functional food industry. Citrus waste that remains after fruit processing is also regarded as a valuable source of value-added phytochemicals. A comprehensive analysis of mandarin composition as a determinant of fruit functional properties, health benefits, and valorization into useful products is represented together with the effect of different processes such as light, wax coating, auxin addition, ozone treatment, and ethylene degreening. Such reviewing evidence is an essential precondition for improving the selling market of mandarin and highlighting its waste valorization potential and its incorporation into useful products produced by pharmaceutical industries. In this study, the phytochemical and biological reports presented to emphasize the needed priority for agricultural techniques to provide a certain mandarin product or trait. In addition, the paper summarizes the optimum conditions applied for the updated extraction techniques for phenolic acids, flavonoids, and oils at a commercial scale from mandarin peels and to enhance its global marketing. A brief representation is given towards potential mandarin patents and the valorization of its bio-waste fruits into commercial products of added value. The review can guide researchers to produce future potentially marketed functional food enriched with mandarin extracts and/or bioactives.
... (MIC = 1.25 mg/mL) [11]. At the concentration of 0.94%, EOL and EOP totally inhibited the growth of dermatophytes A. flavus, A. niger, Penicillium chrysogenum and P. verrucosum [41]. EOP also exhibited a wide inhibitory effect on some fungi cultures. ...
Article
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Citrus, which belongs to the Rutaceae family, is a very widespread genus in the Mediterranean Basin. In Tunisia, various parts of these spontaneous or cultivated plants are used in common dishes or in traditional medicine. The purpose of this work was to investigate C. limon and C. paradisi essential oil (EO). The samples were studied for their chemical composition using SPME/MS, as well as their antibacterial and antifungal activities. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) methods were used to evaluate the anticoagulant potentialities. The obtained results show that both essential oils are rich in monoterpenes hydrocarbons, whereby limonene is the main compound in C. paradisi EO (86.8%) and C. limon EO (60.6%). Moreover, C. paradisi EO contains β-pinene (13.3%), sabinene (2.2%) and α-pinene (2.1%). The antibacterial assay of the essential oils showed important bactericidal and fungicidal effects against all strains tested. In fact, the MICs values of C. limon EO ranged from 0.625 to 2.5 mg/mL against all Gram-positive and Gram-negative bacteria, and from 6.25 to 12.5 mg/mL for Candida spp. strains, while C. paradisi EO was more active against all bacteria with low MICs values ranging from 0.192 to 0.786 mg/mL, and about 1.5 mg/mL against Candida species. Both tested Citrus EOs exhibited interesting anticoagulant activities as compared to heparin. The molecular docking approach was used to study the binding affinity and molecular interactions of all identified compounds with active sites of cytidine deaminase from Klebsiella pneumoniae (PDB: 6K63) and the C (30) carotenoid dehydrosqualene synthase from Staphylococcus aureus (PDB: 2ZCQ). The obtained results show that limonene had the highest binding score of −4.6 kcal.mol−1 with 6K63 enzyme, and −6.7 kcal.mol−1 with 2ZCQ receptor. The ADME profiling of the major constituents confirmed their important pharmacokinetic and drug-like properties. Hence, the obtained results highlight the potential use of both C. limon and C. paradisi essential oils as sources of bioactive compounds with antibacterial, antifungal, and anti-coagulant activities.
... It contains antifungal, antiviral, and antibacterial properties 61 . Citral has the ability to damage the membranes of bacteria and stop the action of vital enzymes including ATPase and gyrase 62 . Lemon oil contains significant amounts of this monoterpene as well. ...
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Onychomycosis, a fungus that causes nail colouring, nail separation, and nail plate growth, has infected the nail unit. There is a chance that the nail structure, nail bed, or nail layer could be infected. The term “onychomycosis” derives from the Greek words “onyx” (nail) and “mykes” (fungus). Around 50% of all consultations for nail diseases are for onychomycosis, the most common nail infection disorder. About 90% of toenail onychomycosis and 75% of fingernail onychomycosis are caused by dermophytes like Trichophyton rubrum and Trichophyton mentagrophytes. About 70% of yeast-borne onychomycosis cases are caused by Candida albicans. Epidemiological studies that have just been released estimate that onychomycosis affects every community worldwide at a rate of about 5.5 per cent. Onychomycosis is managed in different ways based on clinical categorization, the number of damaged nails, and the severity of the condition. The disadvantages of treatment are that oral therapies are frequently limited by drug interactions and probable hepatotoxicity, and topical antifungals have low efficacy if administered without nail plate biosurgery. The use of plants in medical treatments and herbal therapies is one of the less harmful, cheaper, and widely available alternatives to synthetic pharmaceuticals for treating fungal infections. Undoubtedly, dermatophytes can be inhibited by plant-based extracts as well as essential oils’ antifungal activities.
... The flavonoid named hesperetin reported as antioxidant andhas potential to prevent cardiovascular and neurological disorders (Li et al. 2015).Additionally, by-products of Citrus fruits have many industrial applications namely asenzymes, antioxidants, organic acids, ethanol, prebiotics and essential oils (Saeid et al. 2021). The essential oils extracted from lemon, orange, mandarin and grapefruit were reported not only to possess antifungal properties but are also utilized as an alternative to chemicals in food industries (Viuda-Martos et al. 2008). The gel-like properties of pectin from Citrusfruits areutilizedin jellies and jams, dairy products in food, pharmaceutical, and cometic industries (Pagan et al. 2001). ...
Chapter
Citriculture is a highly significant business industry in many countries. However, in order to preserve economic competitiveness, methods beyond commercial concerns are needed, as the expense of managing pests and diseases has a significant impact on its trade value. All Citrus producing countries face the same difficulties in effectively controlling leprosis, HLB, Citrus canker, and various fungal diseases. The majority of the time, the methods used to combat these diseases rely heavily on chemicals, which, when used continuously, can harm the environment and favour the creation of microbes resistant to chemical. Genetic engineering technology is crucial in this situation for the control of diseases of Citrus cultivars, development of resistant cultivars that can meet the nutritional demands of projected human population. An alternative that could lead to more environmentally friendly citriculture is the creation of modified plants utilizing transgenic and genome editing techniques, with the goal of lowering vulnerability of orchards to particular diseases. In this chapter, we have summarized the diseases previously reported in certain species of Citrus fruits and demonstrated the transgenic technologies opted to overcome them for the development of resistant varieties/cultivars.
... Te mold growth is usually seen on the surfaces of cheese during extended period but as the cheese (T 3 ) surfaces were completely covered with Kinnow peel oil (0.6%), therefore mold growth was not visible at the surfaces. Many studies have reported the antifungal activities of citrus essential oils [14,16,46]. Moreover, these oils have also been considered to have bioactivity against spoilage-causing microorganisms [18]. ...
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Kinnow peel oil has been reported to possess antimicrobial and antioxidant activities due to presence of many bioactive compounds. Therefore, the experiments reported in this research paper aimed to investigate the shelf stability and antioxidant potential of Cheddar cheese coated with Kinnow peel oil at various concentrations (0.2%, 0.4%, and 0.6%). The physicochemical characteristics, microbial counts, antioxidant potential, and sensory acceptability of Cheddar cheese were evaluated during ripening (up to 9 months, 4°C). The titratable acidity (%), pH, moisture (%), fat (%), protein contents (%), and soluble nitrogen (SN, %) of Cheddar cheese investigated in the present study showed significant p < 0.05 variations among treatments during ripening. The maximum plate counts (8.36 Log cfu·g−1) were observed in control cheese (T0) ripened for 3 months whereas T3 (9 months ripened) showed the minimum counts (5.04 Log cfu·g−1) among all the treatments. The maximum (3.76 Log cfu·g−1) yeast and mold counts were observed in T0 cheese ripened for 9 month whereas the respective samples of T3 showed the lowest values (2.89 Log cfu·g−1) among all the treatments. The surfaces of Cheddar cheese coated with 0.6% Kinnow peel (T3) did not show any visible signs of yeast and molds. The maximum (366.56 mg GAE/100 g) total phenolic contents were observed in T3 ripened for 6 months. The maximum values (1995.02 mM TE/100 g) of DPPH radical scavenging activity were observed in T3 ripened for 6 months. Similarly, T3 obtained the highest sensory scores among all the treatments. Hence, it was concluded that Kinnow peel oil significantly improved antioxidant potential, sensory perception, and shelf stability of Cheddar cheese.
... Lemon, mandarin, grapefruit, and orange essential oils inhibited the growth of A. niger. Orange essential oil reduced mycelium growth at 0. respectively, followed by lemon, grapefruit, and orange essential oils [117]. Lemongrass, oregano, and thyme essential oils exhibited the strongest inhibitory effect on sporulation for the most resistant tested strains, including A. flavus, A. parasiticus, and A. clavatus [118]. ...
Article
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Essential oils (EOs) are natural products called volatile oils or aromatic and ethereal oils derived from various parts of plants. They possess antioxidant and antimicrobial properties, which offer natural protection against a variety of pathogens and spoilage microorganisms. Studies conducted in the last decade have demonstrated the unique applications of these compounds in the fields of the food industry, agriculture, and skin health. This systematic article provides a summary of recent data pertaining to the effectiveness of EOs and their constituents in combating fungal pathogens through diverse mechanisms. Antifungal investigations involving EOs were conducted on multiple academic platforms, including Google Scholar, Science Direct, Elsevier, Springer, Scopus, and PubMed, spanning from April 2000 to October 2023. Various combinations of keywords, such as “essential oil,” “volatile oils,” “antifungal,” and “Aspergillus species,” were used in the search. Numerous essential oils have demonstrated both in vitro and in vivo antifungal activity against different species of Aspergillus, including A. niger, A. flavus, A. parasiticus, A. fumigatus, and A. ochraceus. They have also exhibited efficacy against other fungal species, such as Penicillium species, Cladosporium, and Alternaria. The findings of this study offer novel insights into inhibitory pathways and suggest the potential of essential oils as promising agents with antifungal and anti-mycotoxigenic properties. These properties could make them viable alternatives to conventional preservatives, thereby enhancing the shelf life of various food products.
... According to Pedroso et al. (2019), MIC of the various C. reticulata EOs against C. albicans ranged from 1000 to >2000 µg/ml. Viuda-Martos et al. (2008) reported limonene and λ-terpinene as the main constituents of C. reticulata EO, accompanied by sabinene, linalyl acetate, copaene, and α-pinene (Boughendjioua et al., 2020). The antifungal activity of C. reticulata EO is previously reported (Denkova-Kostova et al., 2020), but details regarding its antibiofilm activity are scarce. ...
Article
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Microbial biofilms are organized consortiums of microorganisms in the self-produced matrix, characterized by increased resistance to antimicrobial agents. Candida albicans belongs to the regular human microbiota, but it could be highly pathogenic. Essential oils (EOs) are widely distributed secondary me-tabolites, proven for various biological activities. The main goal of this investigation was to evaluate the antifungal and antibiofilm properties of EOs from Citrus limon (L.) Osbeck, C. reticulata Blanco, Nigella sativa L., and Foeniculum vulgare Mill. against C. albicans. Antifungal activity was evaluated through the disk diffusion method, followed by the determination of the minimum inhibitory (MIC) and minimum fun-gicidal concentration (MFC). Antibiofilm assays were implemented through the tissue culture plate method and determination of the biofilm inhibition. Zones of inhibition were detectable for all tested EOs, with the greatest activity of N. sativa (28.30±1.50 mm to 39.30±1.10 mm). MIC values ranged from 62.50 µg/ml (N. sativa) to 125 µg/ml (C. limon), and 250 µg/ml (C. reticulata and F. vulgare). All tested EOs performed an impact on the biofilm-forming capacity of tested yeast. The antibiofilm activity was species-specific and concentration-dependent. The highest antibiofilm activity was recorded for F. vulgare. Obtained results suggest that investigated EOs possess antifungal and antibiofilm potential.
... The antifungal or antibacterial activity of extracts obtained from citrus plants has been frequently highlighted. Viuda-Martos et al. (2008) found that lemon, orange, mandarin, and grapefruit essential oils, obtained by coldpressing the peel, reduced the growth of A. niger and Aspergillus flavus Link. Of these, orange essential oil was found to be the most effective inhibitor of A. niger, and mandarin was the most effective inhibitor of A. flavus. ...
Article
Aspergillus carbonarius (Bainier) Thom. is an important pathogen and ochratoxin A (OTA) producer in grapes that can be controlled by adopting sustainable approaches. Here we evaluate the application of natural plant extracts as an alternative to synthetic fungicides to reduce OTA contamination and to prevent infection of grapes by two isolates of A. carbonarius. In a preliminary screening, natural extracts of chestnut flower, cistus, eucalyptus, fennel, and orange peel were evaluated for their antifungal and anti-mycotoxigenic efficiency in a grape-based medium at concentrations of 10 and 20 mg/mL. Cistus and orange peel extracts demonstrated the best anti-fungal activity at both concentrations. Although the eucalyptus extract demonstrated no significant effect on Aspergillus vegetative growth, it significantly reduced OTA by up to 85.75 % at 10 mg/mL compared to the control. Chestnut flower, cistus, eucalyptus, and orange peel extracts were then tested at the lowest concentration (10 mg/mL) for their antifungal activity in artificially inoculated grape berries. The cistus and orange peel extracts demonstrated the greatest antifungal activity and significantly reduced mold symptoms in grapes. Moreover, all tested natural extracts were able to reduce OTA content in grape berries (17.7 ± 8.3 %-82.3 ± 3.85 % inhibition), although not always significantly. Eucalyptus extract was particularly efficient, inhibiting OTA production by both strains of A. carbonarius by up to >80 % with no effects on fungal growth. The use of natural eucalyptus extract represents a feasible strategy to reduce OTA formation without disrupting fungal growth, apparently maintaining the natural microbial balance, while cistus and orange peel extracts appear promising as inhibitors of A. carbonarius mycelial growth. Our findings suggest that plant extracts may be useful sources of bioactive chemicals for preventing A. carbonarius contamination and OTA production. Nonetheless, it will be necessary to evaluate their effect on the organoleptic properties of the grapes.
... Ozgoli et al. confirmed the higher efficacy of clove aromatherapy than peppermint aromatherapy in reducing levels of pain and anxiety during labor (41). The effects of Mandarin Orange essential oil aromatherapy on labor pain and anxiety: Mandarin orange (Citrus reticulata) is one of the citrus species of the Rutaceae family (56). In a study by Burns et al, it has been shown that using Mandarin essential oil in combination with four other essential oils (Clary sage, Roman chamomile, lavender, frankincense,) significantly decrease labor pain and anxiety (12). ...
Article
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Background: Family-centered empowerment model (FCEM) greatly values the motivational, psychological, and functional roles of children and their family members in health promotion. Its main goal is to strengthen the family system to promote children and family health. Aim: To investigate the effect of FCEM on knowledge and stress level among mothers of children with glucose-6-phosphate dehydrogenase enzyme deficiency(G6PD). Study design: A quasi-experimental design was performed. Setting: The study was conducted in hematology outpatient clinic at Mansoura University Children’s Hospital. Subjects: a purposive sample composed of 60 mothers and their children who are suffering from G6PD deficiency. Tools: Two tools were used for data collection: Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency Knowledge Questionnaire and Arabic version of Perceived Stress Scale. Results: There were an improvement in the mean score of mothers' total knowledge with statistically significant difference (P<0.001) in the post intervention phase compared to pre intervention phase. Mean score of mothers' stress level was 26.90 ± 6.26 pre the FCEM implementation and decrease to17.36 ± 2.73 post FCEM with a statistically significant difference. Conclusion: Applying FCEM on mothers of children with G6PD deficiency leading to improvement of their knowledge regarding G6PD and reduce their level of stress Recommendations: researchers recommended implementing FCEM for all mothers and their children with chronic diseases as a strategy for education and management.
... Citrus limonum EO has been widely utilized in various applications, which include food, medicinal product, detergents, cosmetics products, microbial inhibition, and pest management (Bertuzzi, 2013;Viuda-Martos et al., 2008). The citrus essential oil has been found in various sections of fruits as well as leaves, indicating that limonene, a-pinene, p-cymene, ß-pinene, ß-myrcene, terpinolene, and other components are the main aromatic elements of several citrus species (Caccioni et al., 1998;Buettner et al., 2003). ...
... The bioactive compounds and extracted oils of Citrus have shown a high anti-fungal property [54]. Essential oils extracted from different varieties of Citrus such as orange, lemon, mandarin, and grapefruit have shown anti-fungal activities against Aspergillus niger, A. flavus, Penicillium chrysogenum, and P. verrucosum [80]. The study in Citrus sinensis oil was performed to check the hyphal cell wall and diameter characteristics of fungus. ...
Article
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Citrus, belonging to the Rutaceae family, is a commercial fruit worldwide, and it is mainly recognized for its nutritional, anti-oxidant, and significant medicinal properties. Citruses are a group of multifaceted fruit crops with a rich traditional knowledge, deeply rooted in ethnic culture, and the fruits have been considered to be health-protecting and health-promoting food supplements since ancient times. The presence of secondary metabolites and their bioactivities has led to the development of new alternative drugs in recent years. Diverse secondary metabolites such as flavonoids, alkaloids, carotenoids, phenolic acids, and essential oils and their high bioactive properties have imparted great value to human health based on their anti-oxidative, anti-inflammatory, anti-cancer, cardiovascular protective, and neuroprotective effects. The indigenous Citrus species of India—mainly Northeast India—have distinctive and valuable genetic traits, such as resistance to biotic and abiotic stress, distinctive aroma, flavor, etc. Hence, these species are considered to be repertoires of valuable genes for molecular breeding aimed at quality improvement. There is a need for awareness and understanding among the citrus-producing countries of the exploitation of biodiversity and the conservation of Citrus for sustainable development and bioprospecting. The current review presents a holistic view of Citrus biodiversity from a global perspective, including phytochemical constituents and health benefits. Advanced biotechnological and genomic approaches for Citrus trait improvement have also been discussed to highlight their relevance in Citrus improvement.
... Otros autores (Baratta et al., 1998;Chaisawadi et al., 2005;Chanthaphon et al., 2008;Sharma y Tripathi, 2008;Shukla et al., 2000;Quintana et al., 2010;Viuda-Martos et al., 2008) demuestran actividad inhibitoria del crecimiento y/o germinación de hongos, con análisis antifúngicos a diferentes condiciones, a partir de aceites esenciales de canela, orégano, mejorana, limoncillo, limón, mandarina, pomelo (Citrus paradisi L.) y naranja dulce. Algunos autores mencionan que un posible mecanismo de acción de los aceites sobre el crecimiento de los hongos es debido a los constituyentes con alta hidrofobicidad presentes en la célula, lo que ocasiona trastornos en la permeabilidad y en el transporte de iones y de otros compuestos, así como en la separación de componentes lipídicos de la membrana celular y la mitocondria (Quintana et al., 2010). ...
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Se estudió la conservación de frutos de pepino Cucumis sativus L. con recubrimientos comestibles a base de almidón de yuca y quitosano, incorporándole cinamaldehído. Las muestras fueron tratadas con recubrimientos de almidón y quitosano al 1 % (p/v) y aceite esencial en concentraciones de 0,05 % y 0,15 % (v/v), respectivamente. Las muestras se almacenaron a 10 °C y 80 % de humedad relativa durante 21 días. Se evaluó sólidos solubles, acidez titulable, pH, firmeza y pérdida de peso cada 24 horas, y los análisis microbiológicos se evaluaron cada 72 horas. Se determinó que el tratamiento T4 (quitosano 1% + cinamaldehído 0,15%) extendió la vida útil de los frutos de pepino en 8 días en comparación con los pepinos sin recubrimiento (control). Adicionalmente, se observó que los tratamientos presentaron mayor firmeza y menor pérdida de peso en comparación con el control. En relación con el análisis microbiológico de mohos y levaduras, los resultados demuestran que los tratamientos T3 (quitosano 1 % + cinamaldehído 0,05 %), y T4 (quitosano 1 % + cinamaldehído 0,15 %) fueron estadísticamente diferentes (p < 0,05) a los otros tratamientos y al control durante los 21 días de almacenamiento. Los resultados obtenidos en este estudio expresan la eficacia de los recubrimientos comestibles de quitosano con cinamaldehído como método de conservación en postcosecha del pepino.
... A possible mechanism of action for plant essential components on the growth of fungi has been reported in several studies. It is generally accepted that the essential oil components act on the functionality and the structure of the cell membrane [82]. Low concentrations result in changes in the cell's structure, inhibiting respiration and changing the permeability of the cell membrane, whereas high concentrations lead to severe membrane damage, loss of homeostasis and cell death [83]. ...
... Citrus spp. EOs have been reported to exhibit a wide spectrum of biological activity, including anti-carcinogenic, anti-bacterial, antioxidant, anti-fungal, anti-microbial, anti-spasmodic, anti-diabetic, anti-dermatophyte, and anti-inflammatory activities [7][8][9][10]. ...
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This study evaluates the applicability of enantioselective gas chromatography (eGC) and enantioselective comprehensive two-dimensional gas chromatography (eGC×GC) coupled with flame ionization detection for the stereospecific analysis of designated chiral monoterpenes within essential oils distilled from the leaves of Citrus hystrix (CH), C. limon (CL), C. pyriformis (CP), and C. microcarpa (CM). A cryogen-free solid-state modulator with a combination of enantioselective first-dimension and polar second-dimension column arrangements was used to resolve potential interferences in Citrus spp. leaf oils that can complicate the accurate determination of enantiomeric compositions. Interestingly, considerable variations were observed for the enantiomeric fractions (EFs) of the chiral terpenes. (+)-limonene was identified as the predominant enantiomer (60.3–98.9%) in all Citrus oils, (+)-linalool was the major enantiomer in CM (95.9%), (−)-terpenin-4-ol was the major isomer in CM (66.4%) and CP (61.1%), (−)-α-pinene was the dominant antipode in CL (55.5%) and CM (92.1%). CH contained (−)-citronellal (100%) as the pure enantiomer, while CL and CP have lower proportions (9.0–34.6%), and citronellal is absent in CM. The obtained enantiomeric compositions were compared and discussed with results from eGC using the same enantioselective column. To our knowledge, this work encapsulates the first report that details the EFs of these chiral monoterpenes in Citrus spp. leaf oil.
... (USFDA), se pueden usar con películas y recubrimientos comestibles hasta el límite de lo que proporcionan los máximos efectos protectores sin mucho impacto en las propiedades sensoriales y organolépticas de los alimentos (Viuda-Martos et al., 2008). Por lo tanto, los directores ejecutivos poseen un inmenso potencial para sus aplicaciones en la seguridad, el envasado y la conservación de los alimentos. ...
Article
Essential oils are compounds that are formed by several lipidic aromatic substances found in different parts of a plant. There are many plants with different essential oils and different extraction methods are used to take advantage of the diverse properties they offer. In recent times, the resistance of microorganisms to antibiotics opens the interest to search for new routes of antimicrobial control of natural origin, and within them, essential oils have enormous potential. They have a wide variety of chemical compounds that act establishing synergism relationships to perform antimicrobial, antioxidant, antifungal, antiviral, and other activities that characterize them. Citrus essential oils are an economical, ecological, and natural alternative to chemical preservatives. The extraction of citrus oils from waste peels not only protects the environment, but can also be used in various applications, including food preservation. Current needs to reduce allergenic effects caused by certain foods demand urgent research in this area; studies and applications of citrusderived essential oils show a clear technological and ecological alternative to solve this problem.
... The Lemon grass volatile oil showed the greatest antifungal activity against Aspergillus flavus at concentrations of (0.006-0.03%) by inhibiting the fungal growth and aflatoxin production [39]. The antifungal abilities of Lemon, Mandarin, Grapefruit, and orange oils at a concentration of < 1% were reported against different species of Aspergillus and Penicillium molds [56]. Different EOs and their ingredients showed the most antifungal effects versus C. albicans drug-resistant biofilms by suppressing membrane ergosterol and varied signaling paths that prevent hyphal morphogenesis from the yeast [57]. ...
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Medicinal herbs have an essential function in health and therapy. Bioactives of medicinal plants showed fewer side effects than manufactured drugs and their antioxidant properties are responsible for their different therapeutic properties. Essential oils (EOs) are an aromatic mixture of active components with a strong aroma obtained from aromatic plants. Natural EOs are composed of monoterpenes, sesquiterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes, and phenolics. Because of their volatility, EOs are easily extracted from a variety of natural sources using the steam distillation method. Essential oils are one of the important therapeutic ingredients used in developing new therapeutic vehicles because of their anticancer, antiviral, antidiabetic, anticancer, antibacterial, antioxidant, and aromatherapy capabilities. This review includes different literature to survey the nature of essential oils, therapeutic potentials, and the key components of various essential oils.
... Mostly, they are consumed as aroma flavor in the food industry, including alcoholic and nonalcoholic beverages, marmalades, gelatins, sweets, soft drinks, ice creams, dairy products, jams, candies, and cakes [8][9][10]. Moreover, citrus essential oils exhibited significant importance due to their wide range of biological activities such as antimicrobial [11][12][13], antifungal [14], antioxidant [15], antidiabetic [16], antihyperlipidemic [17], anti-inflammatory, anti-allergic [18], anticancer [19], anxiolytic [20], and insecticidal activity [21]. ...
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The mass-based metabolomic approach was implemented using GC-MS coupled with chemometric analysis to discriminate between the essential oil compositions of six cultivars of Citrus reticulata. The antiaging capability of the essential oils were investigated through measurement of their ability to inhibit the major enzymes hyaluronidase, collagenase, and amylase involved in aging. GC-MS analysis resulted in the identification of thirty-nine compounds including β-pinene, d-limonene, γ-terpinene, linalool, and dimethyl anthranilate as the main components. Multivariate analysis using principal component analysis (PCA) and hierarchal cluster analysis (HCA) successfully discriminated the cultivars into five main groups. In vitro antiaging activity showed that Kishu mandarin (Km) (2.19 ± 0.10, 465.9 ± 23.7, 0.31 ± 0.01 µg/mL), Cara mandarin (Cm) (3.22 ± 0.14, 592.1 ± 30.1, 0.66 ± 0.03 µg/mL), and Wm (8.43 ± 0.38, 695.2 ± 35.4, 0.79 ± 0.04%) had the highest inhibitory activity against hyaluronidase, collagenase, and amylase, respectively. Molecular docking studies on the major compounds validated the activities of the essential oils and suggested their possible mechanisms of action. Based on our result, certain cultivars of Citrus reticulata can be proposed as a promising candidate in antiaging skin care products.
... Due to these properties, there is the possibility of using jasmine EOs in the vapor phase for food preservation [39]. Natural additives are considered to contribute to both quality and safety in a wide variety of foods [40]. In recent times, there has been a growing interest in safe, organic and natural products. ...
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The essential oil of Jasminum grandiflorum has very good biological activity. The present study aimed to analyze the chemical composition and biological activity of J. grandiflorum. The main constituents of J. grandiflorum essential oil were benzyl acetate (37%), benzyl benzoate (34.7%) and linalool (9.6%). The antioxidant activity was 58.47%, which corresponds to 220.93 TEAC. The antimicrobial activity was weak to moderate, with inhibition zones ranging from 2.33 to 5.33 mm. The lowest MIC value was against Candida glabrata. The antimicrobial activity of the vapor phase of the essential oil was significantly stronger than that of the contact application. Biofilm analysis using a MALDI-TOF MS Biotyper showed changes in the protein profile of Pseudomonas fluorescens that confirmed the inhibitory effect of J. grandiflorum. The insecticidal potential of the essential oil against Oxycarenus lavatera and Brassicogethes aeneus was also demonstrated. Due to the properties of J. grandiflorum essential oil, it could find application as a biofilm control agent for the shelf-life extension and storage of fruits and vegetables and as a possible insecticidal agent.
... They are also utilized as natural preservatives because of their wide range of biological activities, which include antioxidant and antimicrobial actions [1]. These strong biological activities are attributed to the presence of terpenes, flavonoids, carotenes, and coumarins [2]. Several studies have investigated the volatile makeup of various parts of Citrus species due to their significant economic importance. ...
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Citrus essential oils are routinely adulterated because of the lack of regulations or reliable authentication methods. Unfortunately, the relatively simple chemical makeup and the tremendous price variations among Citrus varieties encouraged the interspecies adulteration of citrus oils. In this study, a sensitive UPLC-MS/MS method for the quantitation of 14 coumarins and furanocoumarins is developed and validated. This method was applied to screen the essential oils of 12 different Citrus species. This study, to our knowledge, represents the most comprehensive investigation of coumarin and furanocoumarin profiles across commercial-scale Citrus oils to date. Results show that the lowest amount was detected in calamansi oil. Expressed oil of Italian bergamot showed the highest furanocoumarin content and the highest level of any individual furanocoumarin (bergamottin). Notable differences were observed in the coumarin and furanocoumarin levels among oils of different crop varieties and origins within the same species. Potential correlations were observed between bergapten and xanthotoxin which matches with known biosynthetic pathways. We found patterns in furanocoumarin profiles that line up with known variations among the Citrus ancestral taxa. However, contrary to the literature, we also detected xanthotoxin in sweet orange and members of the mandarin taxon. Using multivariate analysis, we were able to divide the Citrus oils into 5 main groups and correlate them to the coumarin compositions.
... However, the inhibitory effect of these EOs on microscopic fungi was reported in the research of other authors. According to Viuda-Martos et al. [50], grapefruit EO was the best in terms of the growth reduction in Penicillium chrysogenum and Penicillium verrucosum when several citrus EOs were tested. Kujur et al. [51] showed significant protection of maize seeds against fungal infection after treatment by nano-encapsulated jasmine EO. ...
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Essential oils (EOs) from aromatic plants seem to have the potential to control several fungal pathogens and food contaminants. Botrytis cinerea is the main strawberry fruit contaminant causing high losses during storage. Here, thirteen EOs applied in the vapor phase were evaluated for their potential to inhibit the growth of three different strains of B. cinerea isolated from strawberry fruits. Eight EOs (lemongrass, litsea, lavender, peppermint, mint, petitgrain, sage, and thyme) were able to completely inhibit the growth of B. cinerea for 7 days when applied at a concentration of 625 μL·L−1. Four EOs with the lowest minimal inhibition concentrations (thyme, peppermint, lemongrass, and litsea) have been tested on strawberry fruits intentionally inoculated by B. cinerea. All four EOs showed high inhibition at a concentration of 250 or 500 μL·L−1, but only peppermint EO was able to completely inhibit B. cinerea lesion development at a concentration of 125 μL·L−1. The sensory evaluation of strawberries treated by EOs at a concentration 125 μL·L−1 resulted in a statistically significant decrease in taste, aftertaste, aroma, and overall quality. Lemongrass and litsea EOs scored better than thyme and peppermint ones, thus forming two viable methods for B. cinerea suppression and the extension of packed strawberries’ shelf life.
... For example, C. x sinensis var. Valencia can inhibit Aspergillus flavus [40], Aspergillus niger, Penicillum chrysogenum, and Penicillum verrrucosum [41] and many other fungal species. Similarly, essential oil extracts for different varieties/cultivars of C. x sinensis have been proven to inhibit Lactobacillus curvatus L. sakei, Staphylococcus carnosus, S. xylosus, S. aureus, and B. subtillis, E. coli [42]. ...
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Oranges and mandarins in Chongqing, China, are mostly processed for juice and their peels are wasted or landfilled. To add value, it is essential to utilize the peels and extract useful materials, such as citrus essential oils (CEOs). Here, we report the metabolome analysis of the peels of Citrus x sinensis (CS) and Citrus reticulata (CR). In total, 793 metabolites were detected in the CS and CR peels, of which 242 were differentially accumulated. The metabolites were grouped into 12 compound classes. Terpenoids were the highest accumulated class of compounds followed by phenols and alcohols in both fruit peels. CR peels were rich in all types of compounds, whereas CS showed a relatively lower content of the detected compounds. The highest accumulated compounds were β-phellandrene, beta-ocimene, 1,3,6-octatriene,3,7-dimethyl, and d-limonene. Overall, CR showed higher compound diversity than CS. The CS and CR peel extracts showed antibacterial effects against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The peel extracts from CR and CS showed similar antibacterial effects against E. coli and B. subtilis, while CS peel extracts were more effective against S. aureus. Overall, our study concludes that both CS and CR peels should not be wasted owing to the CEOs and respective antibacterial activities.
... sinensis) [75]. Many of these monoterpenes have been shown to have potential in medicinal applications to reduce inflammation [76] and as natural antioxidants [77] with numerous antimicrobial and antifungal properties [78][79][80][81][82][83][84][85]. Our GC-MS analysis also detected carene in the EO of both tested citrus species, whereas carvone was found in C. reticulata only. ...
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Aphids are serious pests of a wide range of agricultural crops, including pomegranates and grapevines. In addition, due to the negative environmental impacts of chemical insecticides, these pests are developing important resistance against aphicides. Therefore, one alternative method to control aphids is the use of essential oils (EO). The present study aimed to evaluate the insecticidal activity of Citrus aurantium and C. reticulata peel EO at different concentrations and with different exposure periods to pomegranate and grapevine aphids, Aphis punicae and A. illinoisensis via the topical application method under laboratory conditions. The results reveal that C. aurantium L. EO had greater toxicity against pomegranate and grapevine aphids, with LC50 of 0.37 and 0.82 μL/mL, respectively, at 48 h after application. The highest repellence effect was estimated for C. aurantium EO, at 2.5 μL/cm2, on A. punicae, with a value of 100% after an exposure time of 3 h, in contrast to the 88% repellence estimated for A. illinoisensis. The GC-MS investigation of both essential oils identified limonene, 3-carene, pinene, and p-cymene as active substances that could be attributed to the effects observed. Overall, our results offer a potential tool to control the two aphid species and could help in the development of integrated insect management in pomegranate and grapevine fields.
... niger, Trichoderma viride, Penicillium cyclopium). Viuda-Martos et al. (2008) [18] studied on complete mycelial inhibition of A. niger and A. flavor at a dosage of 0.94% lime, orange, mandarin and grapefruit EOs. They also reported high efficacy of grape EOs against Penicillium verrucosum and P chrysogenum, orange EO against A. niger and mandarin EO against A. flavus. ...
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Since the era of the beginning of the eco-friendly pest management, various plant-based products showed promising actions, and amidst them, essential oils obtained from the leaves, barks, stems and different parts of the plants proved to be a boon towards effective control of various phytopathogens. Essential oils are odoriferous, volatile organic compounds, consisting of a broad spectrum of secondary plant metabolites. Besides their antibacterial, insecticidal, antimicrobial activities, they have enormous potential to reduce the damage due to phytopathogenic fungus. In about 3000 essential oils identified, only 300 found to be economical, and a narrow spectrum of them has been used to manage fungi. As for as their mode of action is concerned, in fungal pathogens, essential oils establish a membrane potential across the cell wall and disrupt ATP assembly, cell walls and their permeability, leading to cell wall damage. Moreover, improvement in formulations like nano and microemulsions and stabilizing formulations has led to a new paradigm towards efficient control of plant pathogenic fungi. Therefore, the present review depicts the involvement of various plant essential oils in fungicidal and fungistatic activities for controlling plant diseases and also emphasizes on the modes of action of various essential oil products and their formulations available. It also reveals the constraints regarding the essential oil formulations which we have to eliminate for further betterment in eco-friendly phytopathogenic fungi management.
... Generally, the antimicrobial efficacy of plants is due to diverse compounds such as phenolics, tannins, and alkaloids (Cowan 1999). Plant extracts can be used as food preservatives because they are referred to as GRAS (Generally Recognised As Safe) (Viuda-Martos et al. 2008) and, thanks to their safety, they have been used for this purpose since ancient times (Ullah et al. 2016). Plant extracts are still very important for processing safe and stable foods because foodborne illnesses still pose a threat even in industrialized countries, even though hygiene standards have steadily improved in recent decades (Newell et al. 2010). ...
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In this study, almond skin of Prunus dulcis L. variety Casteltermini was characterised for its chemical composition and for the inhibitory activity towards food associated microorganisms belonging to pathogenic (Salmonella Enteritidis, Staphylococcus aureus, Escherichia coli and Listeria monocytgenes), spoilage (Pseudomonas poae and Brochotrix thermospacta) and useful (Levilactobacillus brevis and Saccharomyces cerevisiae) groups. The n-hexane extract of P. dulcis skin, investigated by GC-MS, evidenced linoleic, palmitic, and oleic acids as the main abundant compounds. Staphylococcus aureus ATCC 33862 growth was strongly limited by n-hexane extract and the minimum inhibition concentration (MIC) was 25.5 mg/mL. These results highlight the potential of almond by-products as food bio-preservatives as well as pharmaceutical products.
... Thus, when the concentration of pomelo peel EO was greater than 3.5 mg/mL, it exhibited a significant antifungal property. Experiments have demonstrated that PPEO can be used as a natural, pollutant-free pesticide [34,35]. ...
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To verify the anti-fungus properties of the crop-harmful pseudocercospora, the essential oil (EO) of pomelo peel (PP) was extracted by a single factor combined with response surface optimization. Meanwhile, the composition and activity of EO were studied. The PP was squeezed by a screw extruder and pretreatmented by pectinase, then extracted by microwave-assisted steam distillation. The optimal conditions were as follows: pectinase dosage was 69.17 μmol/g, microwave power was 651.42 W and extraction time was 43.84 min. The dry weight (DW) yield of PPEO reached 14.63 mL/kg DW after BBD optimization. There were 23 compounds in the PPEO identified by GC-MS. Limonene, α-phrenbutene, and laurene in PPEO accounted for 79.31%, 4.72%, and 3.46%, respectively. In addition, the antifungal was effective when the concentration of PPEO was 3.5 mg/mL. Therefore, this study has guiding significance for the development of natural resources.
... The inhibitory percentage of EOs at different concentrations against A. flavus is described in Figure 4. The antifungal efficacy of orange peel EOs was dose-dependent manner which was compatible with earlier reported studies (Singh et al., 2010;Viuda-Martos et al., 2008). EOs at 10% was found to inactivate 10% of diameter of mycelial growth and nearly 70% of mycelial growth diameter of A. flavus was inhibited by 50% EOs. ...
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The continuous fresh consumption or juice production of orange fruits (citrus nobilis) has discarded a vast number of orange peels, which has caused significant impacts on environmental issues. This study attempted to utilize discarded orange peels to extract essential oils (EOs) and evaluated their physiochemical properties, antibacterial, antifungal, and antioxidant activities. EOs were extracted via a distillation system using a Clevenger apparatus and gas chromatography - mass spectrometry analysis was employed to characterize their chemical components. The antibacterial and antifungal test were evaluated using a well diffusion method, and antioxidant activity was determined based on DPPH radicals scavenging effect and ferric reducing antioxidant power (FRAP). The obtained EOs with the yield of 3.29 ± 0.24% in which limonene was found to be the most abundant compound in the EOs (90.42%) followed by β-myrcene (4.7%) and α-pinene (1.22%). The result showed that Gram-positive bacterium (Bacillus cereus) was susceptible to the 50% EOs than Gram-negative bacterium (Escherichia coli) with respect to inhibitory zone diameter of 15.00 ± 0.58 mm and 11.33 ± 0.58 mm. The 50% EOs also inhibited nearly 70% of the mycelial growth of Aspergillus flavus as well as exhibiting antioxidant activity with IC50 values of 0.15 ± 0.01 mg/mL and 18.29 ± 0.13 mg/mL for DPPH and FRAP assay, respectively. The orange peel EOs could be a promising alternative to synthetic preservatives in food industry due to their antimicrobial and antifungal activity as well as their antioxidant activity.
... Ciprocin (Ciprofloxacin) is a fluoroquinolone antibiotic used to prevent bacterial infections such as bone and joint infections, intra-abdominal infections, certain types of infectious diarrhea, respiratory tract infections, skin infections, typhoid fever, urinary tract infections, etc. Results from the third disk diffusion test of the peel oil, represented in Table 3, show that the gram-positive S. aureus bacteria was more sensitive to the tested extracts than the other two gram-negative bacteria. Most studies have investigated the action of EOs against food spoilage microorganisms and food-borne pathogens and showed that these oils are slightly more active against the gram-positive than the gram-negative bacteria [46]. They studied the resistance against bacteria and represented the inhibition zones against the ciprofloxacin and erythromycin. ...
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Citation: Plabon, M.E.A.; Mondal, S.C.; Or Rashid, M.M.; Chowdhury, M.K.; Saeid, A.; Althobaiti, F.; Dessok, E.S.; Rehmani, M.I.A.; Mustafa, S.K.; Islam, M.S. Chemical Composition and Anti-Microbial Activity of Hog Plum (Spondias mombin L.) Peel Oil Extracted from Different Regions of Tropical Climates. Horticulturae 2021, 7, 428. https://doi.org/10.3390/ horticulturae7110428 Academic Editors: Dasha Mihaylova and Aneta Popova
Chapter
Kinnow (Citrus reticulate Blanco) also known as mandarin is one of the major produced citrus crop. Kinnow are mainly grown with the objective of juice production and its processing. Major waste produced by citrus processing industry is in the form of seeds, peels, and pomace. Citrus peels and seeds are a potential source of valuable phytochemicals like polyphenols, flavonoids, antioxidants, limonoids, carotenoids and tocopherols which can be isolated for further incorporation into products. These bioactive components have their role in pharmaceutical, food, nutraceutical, cosmetics, paper industry, etc. Due to changes in taste preferences, dietary customs, and consumer behaviour in recent years, there has been a surge in demand for processed Kinnow goods, primarily juice, as a result of increased Kinnow production in India. Scientist are working to exploit the Kinnow juice and by-products for its valorization.
Chapter
Citrus fruits represent the one of the most consumable fruit genus globally. The genus includes sweet orange (Citrus sinensis), lime (Citrus aurantifolia), mandarin (Citrus reticulata), lemon (Citrus limonum) and grapefruit (Citrus vitis). They are rich source of minerals, vitamins as well as various dietary fibres exclusively important to human nutrition and development. Citrus is a fruit whose all parts are processed into value added products. The flesh of the fruit can be juiced, canned and frozen. The juice can also be fermented into wine. The jam, jellies, squash, cakes, pies, marmalades, candies etc. are other food products made from citrus. Besides that, the large waste from citrus processing industries in the form of peel, seeds, pomace has immense application in food sector. They can be processed into various products like skin can be dried and used for the production of essential oils, aromatic compounds while white membrane is used for pectin production. Furthermore, systematic use of citrus byproducts and maintaining its quality during storage is of major concern for food technologists and microbiologists. Various microbiological, physical, and chemical factors affect the stability of these products that ultimately have impact on its shelf life. The present book chapter compiles the phytochemical and nutritional significance of citrus genus fruits, the processing of its various parts into value-added products and their possible usage as a rich source of various functional compounds in food sector. Along with this, the various types of packaging for extending the citrus products’ shelf life are also considered.
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The required processes and steps for making bread include technological and innovative concepts. The current trend is the use of less toxic compounds and green processes. Besides lactic acid bacteria and yeast, other microorganisms with special properties, such as enzymes, new aroma and flavor, exopolysaccharides, and vitamins, among other compounds with beneficial properties, could be added to bread manufacture, improving bread quality and health effects for the consumers. Freeze drying, new encapsulation methods, cryoprotectants, spray drying, fluidized bed drying, and vacuum drying are used for probiotics and microorganism cultures that will be used as starters or biological additives in the fermentation. The same development is observed in the preservation methods, and studies with plant extracts and essential oils have been proposed and introduced, replacing chemical agents, such as propionate, within the clean-label bread formulations concept. Baking science is a growing research line incorporating innovative methods and biological additives.
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Limiting postharvest losses of fruit from fungal attack is a major priority. While synthetic chemical fungicides are efficacious, the development of chemical resistance and consumer concerns are driving reinvestigation of natural antimicrobial agents. This review emphasizes the control of postharvest decay in citrus fruits with the use of some most common essential oils (EO), the efficacy of EOs in combating fungal infection in both in vitro and in vivo models, and the mode of action of EOs along with the potency of photochemical by-products that have also been investigated as antifungal agents.
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One of the aims of sustainable development goals (SDGs) i.e., responsible production and consumption can be achieved through waste valorization. Recent developments in utilization of citrus wastes for its value addition are discussed in this chapter. Information related to different citrus species discussed to evaluate their potential. For the industrial production of bioactive components from citrus waste, extraction options need to be explored. With the aim to reduce the negative environmental impacts of the production techniques, greener protocols are preferred. Thus, different extraction techniques presented with comparative yield potential and related advantages. There is need to create balance between cost of production and greener options to achieve sustainability goals. Application of green processes, e.g., supercritical fluid extraction, microwave- and ultrasound-assisted extractions, and their pros and cons are the central core of the chapter. Analytical techniques involved during the analysis is discussed for its intended purpose. Bioactivity spectrum of different components is elaborated with detail literature reviews. Finally, industrial applications especially in the field of health, food, cosmetics are also discussed for its fruitful utilization.
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The present study describes the chemical composition, antibacterial and antifungal activities of essential oils from Bidens pilosa, a traditional medicinal plant widely distributed in the subtropics and tropics. The essential oils from the fresh leaves and flowers of B. pilosa were analyzed by GC–MS. Forty-four components were identified, of which β-caryophyllene (10.9% and 5.1%) and τ-cadinene (7.82% and 6.13%) were the main compounds in leaves and flowers, respectively. The oils and aqueous extracts of leaves and flowers were subjected to screening for their possible antioxidant activities by using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene bleaching methods. In the former case, the essential oils from leaves and flowers were found to be superior to all aqueous extracts tested with an IC50 value of 47.5 and 49.7μg/ml, respectively, whereas all extracts and essential oils seemed to inhibit the oxidation of linoleic acid in the latter case. The oils from B. pilosa exerted significant antibacterial and antifungal activities against six bacteria and three fungal strains. The inhibitory activity of the flower essential oils in Gram-negative bacteria was significantly higher than in Gram-positive. Our findings demonstrate that the essential oils and aqueous extracts of B. pilosa possess antioxidant and antimicrobial activities that might be a natural potential source of preservative used in food and other allied industries.
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The essential oil from the gum of Pistachio (Pistacia vera L. (Anacardiaceae)) grown in Turkey was obtained by the hydro-distillation method, and its chemical composition was analyzed by GC and GC-MS. Moreover, the antimicrobial activities of the oil against the growth of 13 bacteria and 3 pathogenic yeasts were evaluated using the agar-disk diffusion and minimum inhibitory concentration (MIC) methods. The results showed that the essential oil contained about 89.67% monoterpenes, 8.1% oxygenated monoterpenes and 1.2% diterpenes. alpha-Pinene (75.6%), beta-pinene (9.5%), trans-verbenol (3.0%), camphene (1.4%), trans-pinocarveol (about 1.20%), and limonene (1.0%) were the major components. The antimicrobial results showed that the oil inhibited nine bacteria and all the yeasts studied, and the activities were considerably dependent upon concentration and its bioactive compounds such as carvacrol, camphene, and limonene. Moreover, the essential oil of the gum was found to be more effective yeastcide than Nystatin, synthetic yeastcide. Furthermore, the antibacterial activities of the oil were lower than those of standard antibiotics, ampicillin sodium, and streptomycine sulfate under the conditions studied.
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Carvacrol is a component of several essential oils and has been shown to exert antimicrobial activity. The structural requirements for the activity of carvacrol were determined by comparison to structurally related (nonessential oil) compounds. Removal of the aliphatic ring substituents of carvacrol slightly decreased the antimicrobial activity. The effect of the hydroxyl group of carvacrol on activity could not be determined by simply comparing it to p-cymene, because this compound is immiscible with water; therefore, 2-amino-p-cymene, the amino analogue of carvacrol, which has a similar hydrophobicity and structural characteristics, was used. 2-Amino-p-cymene had similar membrane disruption and bacterial killing characteristics as carvacrol showing that, contrary to previous reports, the hydroxyl group of carvacrol itself is not essential for the antimicrobial activity. However, the observed 3-fold lower activity for 2-amino-p-cymene as compared to carvacrol indicates special features in the antimicrobial mode of action of carvacrol due to the hydroxyl group.
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The antimicrobial activity of three Salvia species, i.e. S. santolinifolia, S. hydrangea and S. mirzayanii, essential oils were investigated. The essential oils were obtained from the aerial parts of plants and analyzed by GC-MS. The main constituents of aforementioned species were alpha-pinene (72.4%), beta-pinene (6.6%) and limonene (5.3%); beta-caryophyllene (25.1%), 1,8-cineol (15.2%) and caryophyllene oxide (11.5%); alpha-terpinenyl acetate (22.6%), 1,8-cineol (21.2%) and linalool (8.9%), respectively. Bioassays exhibited that the property of the oil of S. myrzayanii was superior to others. The antimicrobial activity of essential oil from Salvia species may well be due to the presence of synergy between six tested compounds (linalool, 1,8-cineol, alpha-pinene, beta-pinene, beta-caryophyllene and limonene) and other constituents of the oils with various degrees of antimicrobial activity. Among these, linalool and 1,8-cineol had the highest antimicrobial activity.
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The essential oil from fresh and dried rhizomes of Hedychium coronarium on GC-MS analysis resulted in the identification of 44 and 38 constituents representing 93.91% and 95.41%, respectively. The major components of the essential oil from fresh and dried Hedychium coronarium rhizome were 1,8-cineole (41.42%, 37.44%), beta-pinene (10.39%, 17.4%) and alpha-terpineol (8.8%, 6.7%). The aromatic oil has antifungal as well as antibacterial effects. The antimicrobial activities of the essential oil were individually evaluated against four microorganisms, including two bacteria and two fungi. It was found that the antimicrobial activity was higher in the fresh sample than the dried. Both samples showed a better activity against Trichoderma sp. and Candida albicans than against the bacteria Bacillus subtilis and Pseudomonas aeruginosa.
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Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
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The antifungal potential of essential oils of oregano (Origanum vulgare), thyme (Thymus vulgaris) and clove (Syzygium aromaticum) was determined. To establish this antifungal potential, two molds related to food spoilage, Aspergillus niger and Aspergillus flavus, were selected. The agar dilution method was employed for the determination of antifungal activities. The three essential oils analyzed presented inhibitory effects on both molds tested. Oregano essential oil showed the highest inhibition of mold growth, followed by clove and thyme. Aspergillus flavus was more sensitive to thyme essential oil than A. niger. Clove essential oil was a stronger inhibitor against A. niger than against A. flavus.
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The essential oil isolated from plantlets of Thymus mastichina L. ssp. mastichina cultured in vitro was analyzed by GC and GC/MS. The oil was characterized by the richness of 1,8-cineole (55.5%) and linalool (24.5%). These results are in accordance with the chemical composition previously reported for this taxon. The oil showed antifungal activity against eight pathogenic fungi of die genus Fusarium with MICs and MFCs ranging from 1500 to 2100 μg/mL and from 2.0 to 2.4 mg/mL, respectively.
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The solubility in water of essential oil constituents is directly related to their ability to penetrate the cell walls of a bacterium or fungus. The antimicrobial activity of essential oils is due to their solubility in the phospholipid bilayer of cell membranes. Terpenoids which are characterized by their lability have been found to interfere with the enzymatic reactions of energy metabolism.
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The inhibitory effects of five essential oils (thyme, sage, nutmeg, eucaptus and cassia) against Alternaria alternata were tested at different concentrations (100–500ppm) in vitro. The cassia oil and thyme oil both exhibited antifungal activity against A. alternata. The cassia oil inhibited completely the growth of A. alternata at 300–500ppm. The thyme oil exhibited a lower degree of inhibition 62.0% at 500ppm. Spore germination and germ tube elongation of the pathogens in potato dextrose broth was strongly inhibited in the presence of 500ppm cassia oil. Irreversible inhibition of fungal growth could be caused by exposure to 300ppm and 400ppm cassia oil for 6 days and 500ppm cassia oil for 3 days. Cassia oil at 500ppm reduced the percentage of decayed tomatoes. The experiments on reducing natural decay development of tomatoes gave similar results. Therefore, essential oils could be an alternative to chemicals for control of postharvest phytopathogenic fungi on fruits or vegetables.
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The young mature-green lemon fruit manifests a significantly lower level of postharvest decay as compared to the older yellow fruit. Inoculation with Penicillium digitatum Sacc. demonstrated that the resistance of young fruit to decay is related to a factor localized in the oil glands of the flavedo. The main antifungal compound of lemon flavedo was identified as the monoterpene aldehyde citral. The flavedo of green lemon contained 1.5-2 times higher levels of citral as compared to the yellow fruit. In parallel with citral decline, the flavedo extracts of yellow lemons exhibited an increased level of the monoterpene ester neryl acetate, which exerted practically no inhibitory activity against P. digitatum and, in concentrations below 500 ppm, even stimulated development of the pathogen. During long-term storage of lemon fruit, citral concentration decreased in parallel with the decline of antifungal activity in the peel and with an increase of decay incidence. It is suggested that the level of citral in the flavedo is related to the resistance of lemon fruit to postharvest decay.
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The chemical composition of the essential oils obtained from stem/leaves and flowers/fruits of Ferula szovitsiana (Umbelliferae) were analysed by GC and GC–MS. The composition of the oils samples from stem/leaves and flower/fruits were compared: 51 and 47 compounds were identified in the essential oils of stem/leaves and flowers/fruits, representing 97.7% and 95.9% of the total oils, respectively. Both essential oils were rich in monoterpenes (66.7% and 62.1%, respectively) with neryl acetate as major component (33.0% and 41.5%, respectively). Other abundant compounds for stem/leaves oil were β-caryophyllene (8.9%), -pinene (8.0%), β-pinene (6.7%), bicyclogermacrene (4.5%), caryophyllene oxide (4.1%), limonene (4.6%) and -terpineol (3.2%). These values for flowers/fruits oil were bicyclogermacrene (9.0%), -pinene (5.5%), β-pinene (3.9%), -cadinene (3.5%), and calarene (3.2%). Furthermore, the oils were tested against Gram-positive, Gram-negative bacteria and two pathogenic fungi. It was found that oil from F. szovitsiana represents the most potent antimicrobial candidates with MIC of 1.25 mg/disk for Bacillus subtilis. Copyright © 2007 John Wiley & Sons, Ltd.
Article
Thirty-two essential oils from plants were screened for inhibitory effects on 13 food-spoilage and industrial yeasts. Of these, essential oils of allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme were most inhibitory. Oils were subsequently tested for their effects on biomass production and pseudomycelium formation of eight genera of yeasts. Garlic oil was a potent inhibitor of yeast growth at concentrations as low as 25 ppm. The oils of onion, oregano and thyme were also strongly inhibitory. Essential oils (100 ppm) had no effect on pseudomycelium production by Candida lipolytica. However, all eight essential oils delayed pseudomycelium formation by Hansenula anomala, whereas six oils stimulated pseudomycelium production by Lodderomyces elongisporus. Cinnamon and clove oils were clearly stimulatory to pseudomycelium production by Saccharomyces cerevisiae.
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Monoterpenes have antifungal activity on pathogenic fungi. The purpose of this study was to examine the effect of seven monoterpenes on phospholipid and sterol composition of Sclerotium cepivorum Berk as well as lipid peroxidation of mycelia and sclerotia development. Most of the monoterpenes increased the ergosterol content with a consequent diminution in the phospholipid/sterol ratio. This ratio was significantly decreased by the thymol treatment. When the fungus was grown in the presence of thymol or borneol, the saturated fatty acid content and the lipid peroxides were increased, concomitant with an increase of the sclerotial diameter. These results indicate that thymol and borneol may be promoting generation of lipid peroxides. Sclerotial differentiation was retarded mainly by camphor, 1,8-cineole, linalool and menthol.
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Lemon (Citrus limon cv Fino) juice industry by-products were used to obtain high dietary fiber powder. The effect of processing variables (direct drying, and washing previous to drying) on functional properties, fiber content and type, microbial quality and physicochemical properties of the fiber were evaluated. The obtained fiber powder had good functional, microbial quality and favorable physicochemical characteristics to be used in food formulations. Processing conditions affected fiber composition and properties. Water holding capacity was enhanced by washing (7 g water/g non-washed fiber powder; 12.6 g water/g washed fiber powder) and slightly decreased by the reduction in fiber particle size. Oil holding capacity (6.7 g oil/g fiber powder) was not affected by those factors. Acid detergent and neutral detergent fibers were highest in powder from washed lemon residue (23.73 and 32.91%, respectively). aw was lowest in washed lemon fiber powder (0.13). Washing prevented fiber browning during drying as reflected in color parameters. Washing water rinsed green components. Drying was the responsible for the decrease of bacterial populations (approx. 90% reduction in microbial counts).
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The antifungal activity of Thymus capitellatus oils on Candida, Aspergillus and dermatophyte strains were studied. The essential oils were obtained from the aerial parts of the plants by water distillation and analysed by GC and GC–MS. Three chemotypes were characterized: 1,8-cineole (47.5%), 1,8-cineole/borneol (28.8% and 19.5%, respectively) and 1,8-cineole/linalyl acetate/linalool (27.5%, 20.0% and 17.0%, respectively). The minimal inhibitory concentration (MIC) determined according to the NCCLS protocols (M27-A and M38-P) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida (seven clinical isolates and three ATCC type strains), Aspergillus (five clinical isolates, two CECT and two ATCC type strains) and five dermatophyte clinical fungi strains. The oils exhibited antifungal activity for the dermatophyte strains, with MIC values of 0.32–1.25 µ µ µ µ µl/ml; the chemotype 1,8-cineole/linalyl acetate/linalool proved to be more active. The highest antifungal activity of this oil can be associated with the contribution of the linalyl acetate. In the other hand, all samples showed low activity against Candida and Aspergillus strains.
Article
The antimicrobial effects of essential oil isolated from Myrtus communis L. against Es-cherichia coli, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniaee, Bacillus subtilis, Bacillus licheniformis, Candida albicans and Sac-charomyces cerevisiae were studied. The disc diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oil. The minimal In-hibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) of the oil were determined. The oil was found to have an antimicrobial effect. Kinetics of microbial destruction exhibited that the oil could kill microorganisms within 45 minutes of expo-sure. GC and GC/MS analysis of the oil revealed 32 components. The major components were α-Pinene (29.4%), Limonene (21.2%), 1,8-Cineole (18%), Linalool (10.6%), Linalyl acetate (4.6%) and α-Terpineole (3.1%). The high monoterpenes hydrocarbons such as α-Pinene and Limonene seem to contribute to the strong antimicrobial activity of Myrtus communis L. Further research on antimicrobial effects of essential oils with a view to sub-stituting the common chemical compounds is promising. of Iran. 3 Institute for Research in Forests and Rangelands Km 15, Tehran-Karaj Highway, Tehran, Islamic Repub-lic of Iran. Email address: mrezaee@rifr-ac.org 4 Institute for Research in Forests and Rangelands, Km 15, Tehran-Karaj Highway, Tehran, Islamic Repub-lic of Iran.
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The essential oil extracted from the epicarp of Citrus sinensis exhibited absolute fungitoxicity against the 10 post-harvest pathogens. GC–MS studies of the oil revealed the presence of 10 chemical constituents, of which limonene was found to be the major component (84.2%). The activity of the oil was tested by the poisoned food technique (PF) and the volatile activity (VA) assay and the oils showed greater toxicity in the VA assay than in the poisoned food assay. The nature of the toxicity was studied in the VA assay and it was observed that the oil was fungicidal for the 10 pathogens in the 700ppm (mg/l) to 1000ppm range. The oil was extremely toxic for spore germination and it was found that at 700ppm, spore germination was inhibited in the 10 test fungi out of the 12 tested. Treatment at 300ppm concentration exhibited 70–100% inhibition of spore germination in most of the fungi tested. Scanning electron microscopy (SEM) was done to study the mode of action of the oil in Aspergillus niger and it was observed that treatment with the oil leads to distortion and thinning of the hyphal wall and the reduction in hyphal diameter and absence of conidiophores.
Article
The aerial parts of two endemic Pimpinella [Pimpinella anisetum Boiss. & Ball. and Pimpinella flabellifolia (Boiss.) Benth. ex Drude] were hydro-distilled to produce oils in the yields of 2.07% (v/w) and 2.61% (v/w), respectively. The oils were analysed by GC and GC/MS. Twenty-one and nineteen components were identified, representing 99.5% and 99.7% of the oils, respectively. The main compounds of P. anisetum were (E)-anethole (82.8%) and methyl chavicol (14.5%), whereas limonene (47.0%), (E)-anethole (37.9%) and α-pinene (6.0%) were the major constituents of P. flabellifolia. The oils were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, P. anisetum oil exerted greater antioxidant activity than that of P. flabellifolia oil with an IC50 value of 5.62 ± 1.34 μg/ml. In the β-carotene/linoleic acid test system, the oil of P. anisetum was superior to P. flabellifolia with 70.5% ± 2.86 inhibition rate. Essential oils of the plants studied here were also screened for their antimicrobial activities against six bacteria and two fungi. The oils showed moderate antimicrobial activity against all microorganisms tested.
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Antifungal activity of essential oils of thyme, summer savory and clove were evaluated in culture medium and tomato paste. Aspergillus flavus were inoculated in Sabouraud Dextrose Broth and tomato paste and then 0, 50, 200, 350 and 500 ppm of essential oils were added to each sample and then kept at 25 ± 0.5 °C for 2 months. Results showed that all essential oils could inhibit the growth of A. flavus and the thyme oil and summer savory, showed the strongest inhibition at 350 ppm and 500 ppm, respectively. Taste panel evaluations were carried out in a tomato ketchup base, and the percent of inhibition of each essential oil in tomato paste was lower than culture medium. Taste panel was carried out and sample with 500 ppm thyme oil was accepted by panelists.
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This study examined the effect of volatile components of citrus fruit essential oils on P. digitatum and P. italicum growth. The hydrodistilled essential oils of orange (Citrus sinensis cvv. “Washington navel”, “Sanguinello”, “Tarocco”, “Moro”, “Valencia late”, and “Ovale”), bitter (sour) orange (C. aurantium), mandarin (C. deliciosa cv. “Avana”), grapefruit (C. paradisi cvv. “Marsh seedless” and “Red Blush”), citrange (C. sinensis x Poncirus trifoliata cvv. “Carrizo” and “Troyer”), and lemon (C. limon cv. “Femminello”, collected in three periods), were characterized by a combination of GC and GC/MS analyses. The antifungal efficacy of the oils was then examined at progressively reduced rates. Findings showed a positive correlation between monoterpenes other than limonene and sesquiterpene content of the oils and the pathogen fungi inhibition. The best results were shown by the citrange oils, whose chemical composition is reported for the first time, and lemon. Furthermore P. digitatum was found to be more sensitive to the inhibitory action of the oils.
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The antioxidant and antibacterial effect of rosemary, orange and lemon extracts was investigated in cooked Swedish-style meatballs. Activity in a lard system was established for all the extracts and further determination of the development of rancidity as thiobarbituric acid reactive substances consistently showed that about 50% of the rancidity can be controlled by the citrus preparations. Two of the rosemary extracts (water soluble and oil soluble) were more effective with practically complete elimination of rancidity (TBA values) after a period of 12 days. Rosemary extract activity against lactic acid bacteria and Listeria but not Brochothrix thermosphacta was demonstrated in an agar diffusion test, but in the product only lactic acid bacteria counts were slightly reduced. Sensory analysis results, particularly aroma and acceptability scores, indicated the significant advantages in using rosemary and citrus extracts in rancidity-susceptible meat products.
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Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
Article
The isolated essential oils from seven air-dried plant species were analyzed by gas chromatography-mass spectrometry (GC-MS). Thymus vulgaris (thyme), Origanum vulgare (oregano), and Origanumdictamus (dictamus) essential oils were found to be rich in phenolic compounds representing 65.8, 71.1, and 78.0% of the total oil, respectively. Origanum majorana (marjoram) oil was constituted of hydrocarbons (42.1%), alcohols (24.3%), and phenols (14.2%). The essential oil from Lavandula angustifolia Mill. (lavender) was characterized by the presence of alcohols (58.8%) and esters (32.7%). Ethers predominated in Rosmarinus officinalis (rosemary) and Salvia fruticosa (sage) essential oils, constituting 88.9 and 78.0%, respectively. The radial growth, conidial germination, and production of Penicillium digitatum were inhibited completely by oregano, thyme, dictamus, and marjoram essential oils at relatively low concentrations (250-400 microg/mL). Lavender, rosemary, and sage essential oils presented less inhibitory effect on the radial growth and conidial germination of P. digitatum. Conidial production of P. digitatum was not affected by the above oils at concentrations up to 1000 microg/mL. Apart from oregano oil, all essential oils were more effective in the inhibition of conidial germination than of radial growth. The monoterpene components, which participate in essential oils in different compositions, seem to have more than an additive effect in fungal inhibition.
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The high-speed GC separation and MS characterization of lime oil and lemon oil samples using programmable column selectivity and time-of-flight mass spectrometry is described. The volatile essential oils are separated on a series-coupled (tandem) column ensemble consisting of a polar trifluoropropylmethyl polysiloxane column and a nonpolar 5% phenyl dimethyl polysiloxane column. Both columns are 7 m long. A 50 degrees C/min linear temperature ramp from 50 to 200 degrees C is used, giving an analysis time of approximately 2.5 min. A time-of-flight MS with time array detection and automated peak finding and characterization software was used to identify 50 components in lime oil samples and 25 components in lemon oil samples. Despite numerous cases of extensive peak overlap, spectral deconvolution software was very successful in the characterization of most overlapping peaks. For cases where a more complete chromatographic separation is desirable, the tandem column ensemble is operated in the first-column stop-flow mode to enhance the separation of selected overlapping clusters of peaks. A valve between the junction point of the tandem column ensemble and a source of carrier gas at the GC inlet pressure is opened for 2-5-s intervals to stop the flow of carrier gas in the first column. This is used to increase the separation of target component groups that overlap in the ensemble chromatogram without first-column stop-flow operation. This procedure is used to isolate the peak for limonene, the largest peak in the analytical-ion chromatogram of both the lime and lemon oil samples.
Article
The essential oil of leaves and peel from the Cretan variety Zambetakis (Citrus limon) was obtained by steam distillation with a Clevenger apparatus. The essential oil was subjected to GC-MS analysis, and 35 substances were identified. The main component in both essential oils was limonene. beta-Pinene, myrcene, neral, geranial, neryl acetate, geranyl acetate, and beta-caryophyllene have been identified in the leaf oil. The peel oil contained gamma-terpinene, beta-pinene, myrcene, neral, and geranial. The quantification of volatile substances was based on the internal standard method, using octyl acetate as internal standard, and expressed in milligrams per kilogram of the essential oil. The high contents of neral and geranial were indicative of the high quality of both essential oils. The aroma profile and quantitative variations among the essential oil components were measured at six different time intervals over a period of greater than one year. Differences between the components of lemon leaves and peel were observed.
Article
The chemical composition of the essential oil of the Sardinian dwarf curry plant [Helichrysum italicum G. Don ssp. microphyllum (Willd) Nym] was studied. Genetic analysis suggested the presence of two chemotypes; morphological and chemical differences confirmed the presence of two chemotypes (A and B). The maximum yields were 0.18 and 0.04% (v/w) for flowering tops and stems, respectively. The concentrations of nerol and its esters (acetate and propionate), limonene, and linalool reach their highest values during the flowering stage both in flowers and in stems. Besides the essential oil, type B showed an interesting antifungal activity.