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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Estudo da composição inorgânica e avaliação da atividade biológica de Peperomia pellucida no crescimento de Aspergillus flavus / Inorganic composition determination and evaluation of the biologic activity of Peperomia pellucida in the Aspergillus flavus growth

Fabio Vitorio Sussa 21 December 2011 (has links)
Nas últimas décadas houve um grande avanço em pesquisas no desenvolvimento de medicamentos à base de plantas medicinais. Entretanto, constata-se que há pouca preocupação sobre as concentrações de elementos estáveis, bem como as concentrações de atividade de radionuclídeos naturais das séries do 238U e 232Th em plantas com esta finalidade no Brasil. A presença de minerais e radionuclídeos em plantas constitui um meio de migração destes elementos para o organismo humano, através da ingestão de chás ou medicamentos feitos com ervas medicinais. Peperomia pellucida é conhecida popularmente por erva de jabuti e por suas propriedades medicinais, como cicatrizante, analgésica, bactericida e fungicida. As amostras de Peperomia pellucida e de solo analisadas neste trabalho foram coletadas no Jardim Botânico do Rio de Janeiro e em suas proximidades. A concentração elementar de As, Ba, Br, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb e Zn foi determinada nas folhas, partes aéreas, compreendendo folhas e caule, e raiz de Peperomia pellucida, nos extratos obtidos por maceração e infusão e no solo pela técnica da Análise por Ativação Neutrônica Instrumental (AANI). O método analítico utilizado para determinar os elementos Cd, Hg e Pb foi a Espectrometria por Absorção Atômica e as atividades de 226Ra, 228Ra e 210Pb foram determinadas pela contagem alfa e beta total após separação radioquímica. A qualidade dos resultados obtidos foi verificada pela análise dos materiais de referência certificados IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apples Leaves e NIST 1542 Peach Leaves. Os resultados obtidos nas análises apresentaram boa precisão e exatidão. O óleo essencial e os extratos etanólico e hexânico obtidos das partes aéreas de P. pellucida foram testados in vitro, em placas de Petri, para verificar a atividade antifúngica diante ao fungo Aspergillus flavus. A atividade antifúngica baseou-se na zona de inibição e nos valores de CI50 frente ao patógeno. Também foi determinada a composição química do óleo essencial pela Cromatografia Gasosa acoplada ao Espectrômetro de Massa (GC-EM). / In recent decades, there has been a great advancement in research in developing drugs from plants. Nevertheless, little significant care exists in the literature about the stable concentration of elements, as well as the activity concentration of 238U and 232Th decay products in plants used for this purpose in Brazil. The presence of stable elements and radionuclides in plants constitutes the pathway for their migration to humans, via uptake of tea or remedies made with medicinal herbs. Peperomia pellucida, whose popular name is erva de jabuti, is a plant known by its medicinal usages, such as healing and analgesic properties plus antibacterial and antifungal activities against food fungi. In this study, the elemental composition of Peperomia pellucida and surrounding soil samples collected in the Botanical Garden in Rio de Janeiro was determined; the elemental concentration in the alcoholic extract and infusion processes of dry plants was also determined. The elemental concentration of As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn was determined in the leaves, aerial parts, including leaves, stems and roots of Peperomia pellucida, in their extracts obtained by maceration and infusions and in the surrounding soil by the Instrumental Neutron Activation Analysis (INAA). The analytical methodology used to determine the elements Cd, Hg and Pb was the Atomic Absorption Spectrometry (AAS); the activities of 226Ra, 228Ra and 210Pb were carried out by gross alpha and beta counting, after radiochemical separation. The quality of the obtained results was assured by the analyses of the certified reference materials IAEA-336 Lichen, IAEA-Soil-7, IAEA-326 Radionuclides in soil, NIST 1515 Apple Leaves and NIST 1542 Peach Leaves. The relative standard deviations and the relative errors obtained in these analyses indicated good precision and accuracy of the results. The essential oil, ethanolic and hexane extracts of Peperomia pellucida were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates. The antifungal activity was based on the inhibition zone and IC50 values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS.
52

Citronela de Java (Cymbopogon winterianus Jowitt): efeito da sazonalidade e de reguladores vegetais sobre a multiplicação in vitro e rendimento do óleo essencial / Citronela de Java (Cymbopogon winterianus Jowitt): effect of the seasonally and plant regulators about the propagation in vitro and income of essential oil

Salvaro, Luciani Marcia Scherer 14 February 2007 (has links)
Made available in DSpace on 2017-07-10T17:37:07Z (GMT). No. of bitstreams: 1 Luciani_Marcia_Scherer.pdf: 497371 bytes, checksum: 27b02ebdf1f1cef92c900c635b6a2a91 (MD5) Previous issue date: 2007-02-14 / Secretaria de Estado da Educação do Paraná / Citronella of Java (Cymbopogon winterianus Jowitt.) is an aromatic plant of great economical value, it is also well known in all over the world due to repellent characteristics to its essential oil in citronellal. The propagation in vitro is a good method to multiply citronella, due to the fact that the division of the citronella roots ordinarily used facilitates the cutting contamination. However, there are reports that citronella does not present good results in the propagation in vitro when collected in determined seasonal conditions. Therefore, the aim of this paper was to evaluate the effect of the seasonally about the propagation in vitro of citronella of Java, being used different concentration of IBA and BAP, as well as evaluating the income of the essential oil for each season. The explants were collected in each season of the year and inoculated in MS in addition to combination of IBA and BAP. At the end of 30 days the following variants had been evaluated: Height (cm), number of shootings, formation of callus, oxidation and contamination. In the realized conditions, was observed a good multiplication rate during the summer, being just necessary the addition of 1,0 mg/L-1 of BAP in the medium culture, commonly to this it did not have oxidation in this season. The height only presented significant result in the summer. It had formation of callus in the base of the explants either in the autumn or in the winter and in the summer, but in the summer it had a concomitant increase in the number of shootings. The oxidation was higher in the spring. (100% of oxidation). The contamination did not present significant results in any season, therefore, independent from seasonal condition. The extraction of the essential oil was accomplished in each season of the year by in Clevenger appliance. The great income of the essential oil was gotten in the winter with 1,37% of oil, when the plants were totally bloomy. Although the normal conditions of bloom of citronella in the south region is during the spring and in the beginning of the summer. The spring and the summer had 0, 77 and 0,76% income of essential oil, respective. In the autumn presented a lesser income, with 0,57% of essential oil / A citronela de Java (Cymbopogon winterianus Jowitt.) é uma planta aromática de grande valor econômico e também muito conhecida no mundo inteiro devido a sua propriedade repelente atribuída ao seu óleo essencial, rico em citronelal. A propagação in vitro é uma boa forma de multiplicar a citronela, visto que a divisão de touceiras comumente empregada facilita a contaminação das mudas. No entanto, existem relatos de que a citronela não apresenta bons resultados na propagação in vitro quando coletada em determinadas condições sazonais. Sendo assim, o objetivo deste trabalho foi avaliar o efeito da sazonalidade sobre a propagação in vitro da citronela de Java, utilizando diferentes concentrações de IBA e BAP, bem como avaliar o rendimento do óleo essencial para cada estação. Os explantes foram coletados em cada uma das estações do ano e inoculados em meio MS acrescido de combinações de IBA e BAP. Ao final de 30 dias foram avaliadas as variáveis: altura (cm), número de brotações, formação de calo, oxidação e contaminação de explantes. Nas condições realizadas, foi observada uma boa taxa de multiplicação durante o verão, sendo necessária a adição somente de 1,0 mg L-1 de BAP ao meio de cultura, concomitante a isto não houve oxidação nesta estação. A altura dos explantes somente apresentou resultados significativos no inverno. Tanto no outono, como no inverno e no verão houve formação de calo na base dos explantes, sendo que no verão houve também o aumento no número de brotações por explante. A oxidação se deu de forma mais intensa na primavera (100% de oxidação). Para a contaminação de explantes não houve resultados significativos para nenhuma estação, sendo, portanto, independente das condições sazonais. A extração do óleo essencial foi realizada em cada estação do ano utilizando um aparelho de Clevenger. O maior rendimento do óleo essencial foi obtido no inverno, com média 1,37% de óleo, sendo este o momento em que as plantas matrizes se encontravam plenamente floridas. No entanto, as condições normais de florescimento da citronela na região sul são durante a primavera e início do verão. Na primavera e verão o rendimento do óleo essencial foi de 0,77 e 0,76% respectivamente. No outono foi constatado o menor rendimento, com 0,57% de óleo essencial
53

Modelagem, simulação e otimização de uma unidade industrial de extração de óleos essenciais por arraste a vapor

Sartor, Rafael Busato January 2009 (has links)
Este trabalho aborda a modelagem matemática do processo de extração de óleos essenciais por arraste a vapor e a otimização deste processo em escala industrial. Utilizouse dados experimentais de óleos essenciais de alecrim e citronela obtidos em uma unidade industrial de extração por arraste a vapor. O modelo é constituído de um sistema de equações diferenciais parciais, que representam o balanço de massa unidimensional nas fases vapor e sólido. Para resolver o modelo desenvolvido, utilizouse o método das linhas com o uso da técnica de diferenças finitas para discretizar a coordenada espacial e suas derivadas, resultando em um sistema de equações diferenciais ordinárias implementado no simulador EMSO. Os parâmetros do modelo foram estimados pelo método dos poliedros flexíveis, utilizando dois conjuntos de dados experimentais e um terceiro para sua validação. O modelo ajustou-se bem aos dados experimentais industriais, resultando, para duas condições ambientais e geográficas das plantas aromáticas de alecrim, em coeficiente global de transferência de massa de 8,64 x 10 -4 s -1 e 9,10 x 10 -4 s -1, e a constante de equilíbrio de 2,72 x 10 -4 m3=kg e 1,07 x 10 -2m3/kg. Enquanto que para a citronela obteve-se coeficiente global de transferência de massa de 8,29 x 10 -4s -1 e 1,23 x 10 -3 s -1, e constante de equilíbrio de 1,25 x 10 -2 m3/kg e 1,52 x 10 -3 m3/kg. Foi proposto também um problema de otimização para determinar o tempo ótimo de extração e o número de bateladas por dia. Os resultados da otimização do processo indicam que se pode reduzir o tempo de extração, permitindo que outras extrações sejam realizadas por dia, maximizando o volume de óleo extraído ao fim do dia. / This work has as objective the development of a mathematical model of essential oils extraction by steam distillation and the optimization of this process on an industrial scale. We used experimental data obtained from rosemary and citronella in an industrial steam distillation unit. The model consists a system of partial differential equations, which represent the one-dimensional mass balance in steam and solid phases. To solve the developed model, we used the method of lines with the finite differences technique to discretize the spatial coordinate and its derivatives, resulting in a system of ordinary differential equations implemented in the EMSO simulator. The model parameters were estimated by the method of flexible polyhedra, using two experimental runs and a third experimental run to test the model. The model fitted to the experimental data industry, resulting, for two environmental and geographical conditions of rosemary, in mass transfer coefficients of 8,64 x 10 -4 s -1 and 9,10 x 10 -4 s -1, and the equilibrium constant of 2,72 x 10 -4 m3/kg and 1,07 x 10 -2m3/kg. For citronella, the obtained mass transfer coefficient of 8,29 x 10 -4 s -1 and 1,23 x 10 -3 s -1 and equilibrium constant of 1,25 x 10 -2 m3/kg and 1,52 x 10 -3 m3/kg. It was also proposed an optimization problem to determine the optimum extraction time and number of batches per day. The optimization results indicate that the process can reduce the extraction time, allowing other extractions are performed each day, maximizing the essential oil volume extracted in the day.
54

Formação de micropartículas de limoneno em polissacarídeos usando CO2 supercrítico / Formation of microparticles of limonene in polysaccharides using supercritical CO2

Machado, Luciana Cristina 27 June 2014 (has links)
Este trabalho teve como objetivo a utilização da tecnologia que emprega CO2 em estado supercrítico para estudar a formação de micropartículas de óleos essenciais encapsulados em polissacarídeos. O referido tema tem caráter inovador e inédito, já que a tecnologia supercrítica tem sido utilizada na formação e impregnação de partículas, principalmente de solutos sólidos, mas não tem sido aplicada na encapsulação de óleos essenciais. Os processos estudados, RESS (Rápida Expansão de uma Solução Supercrítica) ou o PGSS (Partículas de Soluções ou Suspensões em Gás Saturado) envolvem baixas temperaturas, possibilitando a não degradação de compostos voláteis e termossensíveis, tornando-os mais estáveis. Foram utilizados nesta pesquisa, polímeros que são, normalmente, utilizados no processo convencional de \"aroma em pó\". Mesmo sendo insolúveis ou parcialmente solúveis em CO2 supercrítico houve o intuito de aproveitar estudos comprovados de estabilidade de óleos essenciais encapsulados nestes materiais e ainda manter o custo do produto já que polissacarídeos tem, relativamente, baixo valor comercial, quando comparado aos polímeros que são empregados nos estudos que usam estes processos. Ensaios preliminares foram realizados com diferentes polímeros: Amido modificado, dextrina, maltodextrina e Purity Gum Ultra®, (gentilmente cedidos pela Corn Products, atual Ingredion Incorporated, Mogi Guaçu, SP, BR) no intuito de selecionar o material de parede mais apropriado para a microencapsulação do óleo essencial, representado pelo limoneno. Os resultados preliminares comprovaram que houve impregnação e possível microencapsulação do limoneno, observados e constatados através de análises de microscopia (óptica, eletrônica e de fluorescência confocal a laser) especialmente para Purity Gum Ultra®, a qual apresentou comportamento desejável como estabilidade da dispersão preliminar e morfologia, em comparação com os outros polissacarídeos testados (dextrina, amido modificado e maltodextrina). Os ensaios subsequentes (dimensionamento das partículas, microscopia eletrônica de varredura, microscopia confocal na presença de fluoresceína, estabilidade térmica e quantificação do teor de limoneno microencapsulado) determinaram definitivamente a eficiência da Purity Gum Ultra® como polímero mais apropriado como agente encapsulante, e com isso foi demonstrada a eficiência da técnica proposta para esta finalidade. Ainda, a técnica de microencapsulação empregada (PGSS) apresentou valores significativos na retenção do limoneno com até 86% quando a suspensão foi preparada utilizando etanol (EtOH) e lecitina de soja como surfactante, sendo um relevante indicativo de que o processo de microencapsulação via PGSS proporcionou eficiente retenção do limoneno, além de apresentar outras vantagens sobre os processos de microencapsulação convencionais utilizados na indústria de alimentos. O processo de microencapsulação que utiliza CO2 supercrítico é considerado como \"tecnologia limpa\", aliado a este solvente ser considerado abundante, barato e ambientalmente seguro. Neste estudo constatou-se que, além do emprego de baixa temperatura no processo (50 - 60º C), não houve necessidade do emprego de água na suspensão. / This study aimed to use the technology that employs CO2 in supercritical state to study the formation of microparticles encapsulated essential oils in polysaccharides. The supercritical technology has been used in impregnating particles, mostly of solid solutes, but has not been applied to the encapsulation of essential oils. The studied processes RESS (Rapid Expansion of a Supercritical Solution) or PGSS (Particles Solutions or Suspensions in Saturated Gas) involving low temperatures, not allowing degradation of volatile and polymers that are normally used in the conventional process of \"aroma powder\" were used in this study. Even though it is insoluble or partially soluble in supercritical CO2 proven in order to take advantage of the stability studies of encapsulated essential oils in these materials and still keep the cost of the product as polysaccharides have relatively low value when compared to the polymers that are employed in studies using these processes. Preliminary tests were performed with different polymers : modified starch, dextrin, maltodextrin and Purity Gum Ultra ®, ( kindly provided by Corn Products, Current Ingredion Incorporated, Mogi, SP, BR ) in order to select the most appropriate material for wall microencapsulation of essential oil, represented by limonene. Preliminary results showed that there was possible impregnation and microencapsulation of limonene, observed and recorded through analysis of microscopy (optical, electron and confocal) especially for Purity Gum Ultra ®, which showed desirable behavior such as dispersion and stability of primary morphology compared to other polysaccharides tested (dextrin, modified starch and maltodextrin). Subsequent tests (particle sizing, scanning electron microscopy, confocal microscopy in the presence of fluorescein, thermic stability and quantification of the limonene content microencapsulated definitely determined the efficiency of Purity Gum Ultra ® as the most appropriate polymer as agent encapsulating and it has been demonstrated the efficiency of the proposed technique for this purpose. The technique employed for microencapsulation (PGSS) showed significant amounts of limonene retention of up to 86% when the suspension was prepared using ethanol (EtOH) and soy lecithin as surfactant. Being indicative of a material that microencapsulation by PGSS provided efficient retention of limonene, besides other advantages over conventional microencapsulation processes used in the food industry. The microencapsulation process that uses CO2 supercritical is considered \"clean technology \" due to the low toxicity of CO2 besides this solvent is considered abundant, inexpensive and environmentally safe. In this study it was found that, in addition to using low temperature process ( 50 - 60º C ), there was no need for the use of water in suspension.
55

Comparação ecotoxicológica de princípios ativos de repelentes para invertebrados aquáticos irradiados e não irradiados com radiação gama / Ecotoxicological comparison of active ingredients of repellents for aquatic invertebrates irradiated and non-irradiated with gamma radiation

Gimiliani, Giovana Teixeira 25 February 2013 (has links)
Nas últimas décadas, a introdução de produtos de uso diário nos ambientes aquáticos tem sido uma das questões mais discutidas no que se refere ao monitoramento ambiental. Estes produtos não são totalmente removidos pelos processos convencionais de estações de tratamento de esgoto e de água e são continuamente inseridos no ambiente aquático. O Dietiltoluamida, um princípio ativo de repelente de insetos bastante utilizado mundialmente, é um composto ambientalmente persistente e sua toxicidade para alguns organismos aquáticos tem sido comprovada. Em substituição aos produtos sintéticos, a população tem optado em utilizar produtos naturais, sendo cada vez mais comum o uso de repelentes com óleos essenciais de gramíneas. O óleo essencial de capim-limão é um dos mais utilizados nas formulações de cosméticos e de cuidados pessoais. Entretanto, nenhum estudo tem comprovado a sua toxicidade para a biota aquática. Além dos poluentes químicos, os organismos aquáticos podem estar sujeitos à exposição da radiação ionizante proveniente de fontes naturais (background radiation) ou nas proximidades de instalações de usinas nucleares. O presente estudo avaliou a reprodução de invertebrados aquáticos C. silvestrii após a exposição à radiação gama e posteriormente submetidos aos princípios ativos de repelente sintético e natural. Para isso, avaliou-se a citotoxicidade in vitro bem como a ecotoxicidade aguda e crônica dos princípios ativos e o efeito da radiação gama para D. similis e C. silvestrii. Os ensaios com radiação gama foram realizados sob as mesmas condições dos testes de ecotoxicidade, utilizando o irradiador Gamma-Cell com fonte de Co60. De acordo com os resultados obtidos, o óleo essencial apresentou efeito citotóxico igual a 50 mg.L-1 enquanto para o dietiltoluamida, foi de 420 mg.L-1. O efeito tóxico agudo na sobrevivência (CE50) foi encontrado na concentração de 7,2 mg.L-1 e 3,8 mg.L-1 de óleo essencial para D. similis e C. silvestrii, respectivamente. Concentrações de 64,9 e 53,9 mg.L-1 de dietiltoluamida apresentaram efeito agudo na sobrevivência de D. similis e C. silvestrii, respectivamente. 3,4 mg.L-1 foi estabelecida como a concentração de inibição (CI25) de óleo essencial para o dietiltoluamida correspondeu a 16,4 mg.L- 1, ambos para C. silvestrii. As doses letais de radiação gama que causaram efeito agudo na sobrevivência (DL50) foram de 242 Gy para D. similis e 525 Gy para C. silvestrii. A reprodução de C. silvestrii apresentou redução de 25% na dose de 29 Gy. Depois de determinar a ecotoxicidade dos princípios ativos e o efeito da radiação gama, os organismos foram irradiados com dose de 25 Gy, sendo a maior dose que não causou efeito na reprodução de C. silvestrii, e posteriormente foram expostos às mesmas concentrações utilizadas para os princípios ativos. Os resultados mostraram que a reprodução de C. silvestrii não foi afetada significativamente após a irradiação dos organismos testados quando comparada com os organismos não irradiados. / Over the last decades, the introduction of personal care products in aquatic environments has been one of the most discussed issues regarding environmental monitoring. These products are not completely removed by conventional sewage and water treatment processes and are continuously inserted into the aquatic environment. Diethyltoluamide an active ingredient in insect repellents widely used worldwide is an environmentally persistent compound and its toxicity to some aquatic organisms has been proven. In order to replace synthetic products, people have opted to use natural products which made more common the use of repellents with essential oils of grasses. The essential oil of lemongrass is one of the most used in the formulations of cosmetics and personal care. However, no study has proven its toxicity to aquatic biota. In addition to chemical pollutants, aquatic organisms may be subject to exposure of ionizing radiation from natural sources (background radiation) or near nuclear installations. The present study evaluated the reproduction of aquatic invertebrates C. silvestrii after exposure to gamma radiation and further submitted to synthetic and natural repellents. On this account, we evaluated the in vitro cytotoxicity as well as acute and chronic ecotoxicity of the diethyltoluamide and lemongrass oil, as well as the effect of gamma radiation over D. similis and C. silvestrii. Irradiation experiments were carried out under the same conditions as performed for ecotoxicity assays, using a Gamma-Cell irradiator with a Co60 source. According to the results, the essential oil presented a cytotoxic effect at concentrations of 50 mg.L-1 whereas diethyltoluamide at 420 mg.L-1. The acute toxic effect on survival (EC50) was found at concentrations of 7.2 mg.L-1 for essential oil to and 3.8 mg.L-1 for D. similis and C. silvestrii respectively. Concentrations of 64.9 and 53.9 mg.L-1 of diethyltoluamide showed acute effect on survival of D. similis and C. silvestrii, respectively. 3.4 mg.L-1 of essential oil was established as the inhibition concentration (IC25) while for diethyltoluamide such value corresponded to 16.4 mg.L-1, both over C. silvestrii. The lethal doses induced by gamma radiation revealed an acute effect on survival (LD50) at 242 Gy for D. similis and 525 Gy for C. silvestrii. The reproduction C. silvestrii decreased by 25% at a dose of 29 Gy. After determining the ecotoxicity of the active ingredients and the effect of gamma irradiation, the organisms were irradiated at 25 Gy, which corresponded to the higher dose which caused no effect over the reproduction C. silvestrii and were subsequently exposed to the same concentrations used for the active ingredients. The results showed that reproduction C. silvestrii was not significantly affected after irradiation of the assayed organisms when compared to non-irradiated organisms.
56

Assessment of ethanol, honey, milk and essential oils as potential postharvest treatments of New Zealand grown fruit.

Lihandra, Eka Manggiasih Unknown Date (has links)
Brown and Penicillium rot (blue and green mould) are the most common postharvest diseases in New Zealand, causing significant postharvest fruit losses. Current practice uses fungicides to control the postharvest diseases; however there are perceived health risks associated with the use of such chemicals. Recently, there has been substantial interest in chemicals that are considered Generally Regarded as Safe or GRAS and natural products as alternative postharvest treatments to replace currently used fungicides. In this study, ethanol (GRAS chemical) and the natural products honey, milk and essential oils (lemon, lemongrass, manuka and orange) were assessed as potential alternative treatments to replace the currently used fungicides on both peaches and oranges. In pilot studies ethanol was applied to the fruit by either vapour or dipping (30 seconds or 1.5 minutes). Honey, milk and essential oils were applied by dipping at 30 seconds. Essential oils were also tested using a microtiter assay. Exposing fruit to ethanol vapour proved effective at inhibiting fungal growth, but impacted negatively on fruit quality. Peaches that were exposed to 70% to 100% ethanol vapour were protected against fungal infection for up to 30 days when stored at either 4ºC or room temperature. This is compared to two days for untreated peaches and three days for fungicide -treated peaches. However, the ethanol-treated peaches suffered from severe browning. In contrast, 20% ethanol protected peaches for ten days when stored at 4ºC and two days at room temperature. The fruit that were exposed to 20% ethanol did not brown as a result of the treatment. Oranges that were exposed to 20%, 50%, 70% and 100% ethanol vapour were protected from fungal inhibition for 30 days at both 4ºC and room temperature, but they too suffered from severe browning. Dipping was not as effective as vapour at protecting against fungal infection, but had a little effect on fruit quality. Peaches dipped in 20% to 100% ethanol were completely rotten by ten days when stored at room temperature, but the peaches experienced little to no browning. Untreated and fungicide-treated fruit were protected for one day and two days, respectively. Milk and honey do not appear to have potential as postharvest treatments. Peaches that were treated with 20%, 50% and 100% whole milk and 50% manuka honey showed greater degree of fungal infection compared to untreated peaches after both room temperature and 4ºC storage. At room temperature, peaches that were exposed to 20%, 50% and 100% milk were completely rotten at eight days, compared with ten days for untreated peaches. In contrast, at 4ºC, peaches that were treated with 100% milk were completely rotten at 30 days, while only a slight fungal infection observed on untreated fruit. Similar to milk, honey-treated peaches were also completely rotten at 30 days at 4ºC storage.In vitro (microtiter) assay of the essential oils showed that orange and manuka oils appeared to be effective only at high concentrations. In contrast, lemongrass and lemon oils appeared to be effective even at low concentrations. Of the essential oils tested in the in vivo assay, lemongrass and lemon oils have the greatest potential. Oranges that were exposed to 0.05% lemongrass oil, 0.25% and 0.5% lemon oil were protected for 30 days when stored at 4ºC or room temperature. They provided the best antifungal activity compared to the other concentrations of all four essential oils tested as well as fungicide treatment for 30 days. Of all the treatment tested, 0.05% lemongrass oil, 0.25% and 0.5% lemon oil appeared to be the most promising treatments. However, these treatments need to be tested for antifungal effects, fruit quality, flavour and nutritional effects in large scale experiments before they can be applied as replacements to currently used fungicides. Also, essential oils are complex compounds; therefore it would be of interest to determine the active compound(s) of the lemongrass and lemon oils.
57

Monoterpene production and regulation in lavenders (Lavandula angustifolia and Lavandula x intermedia)

Boeckelmann, Astrid 11 1900 (has links)
Lavenders (Lavandula) are widely grown for their essential oils, which have extensive applications in cosmetics, hygiene products and alternative medicine. The therapeutic and olfactory properties of lavender essential oils are attributed to monoterpenes, a class of low molecular weight (C₁₀) isoprenoids. Oil composition in these plants is primarily determined by plant genotype, but can also be influenced by developmental and environmental factors. In order to define some of the mechanisms that control monoterpene abundance in lavenders, I measured the abundance of quality-defining monoterpenes in several L. angustifolia and L. x intermedia cultivars grown in the Okanagan. Data obtained confirmed that essential oil yield, as well as the abundance of camphor, borneol, linalool, and limonene was species-specific. L. angustifolia cultivars contained high amounts of linalool but yielded little oil, whereas L. x intermedia cultivars were rich in camphor and total oil. Monoterpene abundance changed during flower development, and differed between vegetative and reproductive tissues indicating differential regulation of the biosynthetic pathways, or specialized ecological functions. The abundance of linalool correlated with the transcription of the linalool synthase gene, suggesting that linalool production is in part regulated transcriptionally. However, the degree of correlation between linalool abundance and linalool synthase transcription differed between L. angustifolia and L. x intermedia, suggesting additional, and differing mechanisms that control linalool abundance in these species. In addition, monoterpene abundances were subject to loss during storage and suboptimal detection, two factors that must be considered in future analyses. Results obtained in this study provide insight into the regulation of monoterpene production in lavenders, and build the basis for future research aimed at improving essential oil production in these plants.
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Monoterpene production and regulation in lavenders (Lavandula angustifolia and Lavandula x intermedia)

Boeckelmann, Astrid 11 1900 (has links)
Lavenders (Lavandula) are widely grown for their essential oils, which have extensive applications in cosmetics, hygiene products and alternative medicine. The therapeutic and olfactory properties of lavender essential oils are attributed to monoterpenes, a class of low molecular weight (C₁₀) isoprenoids. Oil composition in these plants is primarily determined by plant genotype, but can also be influenced by developmental and environmental factors. In order to define some of the mechanisms that control monoterpene abundance in lavenders, I measured the abundance of quality-defining monoterpenes in several L. angustifolia and L. x intermedia cultivars grown in the Okanagan. Data obtained confirmed that essential oil yield, as well as the abundance of camphor, borneol, linalool, and limonene was species-specific. L. angustifolia cultivars contained high amounts of linalool but yielded little oil, whereas L. x intermedia cultivars were rich in camphor and total oil. Monoterpene abundance changed during flower development, and differed between vegetative and reproductive tissues indicating differential regulation of the biosynthetic pathways, or specialized ecological functions. The abundance of linalool correlated with the transcription of the linalool synthase gene, suggesting that linalool production is in part regulated transcriptionally. However, the degree of correlation between linalool abundance and linalool synthase transcription differed between L. angustifolia and L. x intermedia, suggesting additional, and differing mechanisms that control linalool abundance in these species. In addition, monoterpene abundances were subject to loss during storage and suboptimal detection, two factors that must be considered in future analyses. Results obtained in this study provide insight into the regulation of monoterpene production in lavenders, and build the basis for future research aimed at improving essential oil production in these plants.
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Antilisterial Characteristics of Volatile Essential Oils

Slaughter, Leeann L. 01 January 2013 (has links)
This study explored the in vitro and in situ antilisterial inhibitory activity of 16 essential oils during indirect exposure: Spanish Basil oil (Ocimum basilicum), Bay oil (Pimenta racemosa), Italian Bergamot oil (Citrus bergamia), Roman Chamomile oil (Anthemis nobilis), Sir Lanka Cinnamon oil (Cinnamomum zeylanicum), Citral, Clove Bud oil (Syzygium aromaticum), Cumin Seed oil (cuminum cyminum), Eucalyptus oil (Eucalyptus globulus), Eugenol, Geranium extract (Pelargonium graveolens), Marjoram oil (Origanum majorana), Neroli extract (Citrus aurantium), Peppermint oil (Mentha piperita L.), Rosemary oil (Rosmarinus officinalis L.),and Spanish Sage oil (Salvia officinalis L.). All essential oils were tested against Listeria monocytogenes (ATCC 4644). In vitro inhibitory activity was determined using the microatmosphere method at three temperatures (37°C, 24°C, 4°C) and six possible volumes (0, 10µl, 25µl, 50µl, 100µl, 150µl, or 200µl). In situ inhibitory activity was determined using inoculated bologna slices packaged in Modified Atmosphere Packaging (80% O2, 20% CO2). Essential oils (0, 0.13ml, 1.35ml, or 2.70ml) were injected into the sample packages adjacent, but not touching, the bologna slices and stored at 24°C for 24h. Basil oil displayed the least antilisterial activity across the three temperature applications in vitro. Peppermint, Cumin Seed, and Citral consistently exhibited the greatest antilisterial activity among the temperature applications in vitro. However, only Eugenol applied at 1.35ml achieved a mean one log10 CFU/ml reduction in LM in situ, which could not be replicated. Peppermint (P < 0.048) displayed significant differences between application volumes (0.13ml, 1.35ml) but did not attain a mean one log10 CFU/ml reduction in LM. This study suggests that while various essential oils can display antilisterial activity in vitro, transitioning into a MAP food system warrants further research in mode of actions and application volumes.
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Oleoegelio su čiobrelių eteriniu aliejumi sudėties moduliavimas ir kokybės vertinimas / The Composition Modeling and Quality Assessment of Oleogel With Thyme Essential Oil

Stukaitė, Aurelija 30 June 2014 (has links)
Pėdų grybelis (lot. Tinea pedis) – tai dermatofitų Trichophyton rubrum, Trichophyton mentagrophytes ir Epidermophyton floccosum sukeltas lėtinis pėdų, kojų tarpupirščių pažeidimas, pasireiškiantis odos įtrūkimais, pleiskanojimu, nemaloniu kvapu ir niežuliu. Vaistinio čiobrelio (lot. Thymus vulgaris L.) eterinis aliejus, savyje turintis timolio (36 – 55 proc.), gali apsaugoti pėdas nuo grybelio atsiradimo. Čiobrelių eterinį aliejų patogu įvesti į aliejinę terpę, tačiau aliejinius tirpalus naudoti nėra patogu. Todėl šio darbo tikslas pagaminti lipofilinį gelį, skirtą pėdų grybelio prevencijai. Šis tyrimas apima: 1) timolio kiekio nustatymą čiobrelių eteriniame aliejuje; 2) optimalaus aliejaus ir gelifikuojančios medžiagos santykio parinkimą; 3) pagaminto lipofilinio gelio su čiobrelių eteriniu aliejumi klampos, pH reikšmės ir išvaizdos įvertinimą; 4) oleogelio veiksmingumo nustatymą, atliekant mikrobiologinį tyrimą. Rezultatai: ESC būdu nustatyta, kad čiobrelių eteriniame aliejuje timolio yra 41,06±0,03 proc. Oleogelio pagrindu nuspręsta naudoti alyvuogių aliejų, nes skystojo parafino ir alyvuogių aliejaus mišinys nesudarė stabilios gelinės struktūros. Pagaminti oleogeliai visą stebėjimo laiką (6 mėn.) išlaikė savo išvaizdą – vientisą struktūrą, skaidrumą, šviesiai geltoną spalvą, čiobrelių kvapą ir pusiau kietą konsistenciją. Atlikus pH reikšmės stebėjimus nustatyta, kad oleogelių pH reikšmė reikšmingai nekito ir išliko atitinkanti žmogaus fiziologinę odos pH reikšmę... [toliau žr. visą tekstą] / Foot fungus (lat. Tinea pedis) is a skin disease caused by dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum. The symptoms are cracks, itch, dandruff and unpleasant odor of the feet skin. Thyme (lat. Thymus vulgaris L.) essential oil containing of 36 – 55 percent of thymol can protect feet from fungus. Thyme essential oil is convenient to introduce in oil medium, but oil solutions are uncomfortable to use. Therefore, the aim of this work is to produce a lipophilic gel for prevention of foot fungus. This study includes the following: 1) determining the amount of thymol in the thyme essential oil; 2) determination of the optimal ratio of oil and gelling agent material; 3) pH value and appearance evaluation of the produced lipophilic gel with thyme essential oil viscosity; 4) the effectiveness of the lipophilic gel in microbiological research. The results: using HPLC method it has been found out that thyme essential oil contains 41.06±0.03 percent thymol. It was decided to use olive oil on oleogel basis because liquid paraffin and olive oil mixture didn’t make stable gel structure. Produced oleogels kept the same appearance features for all observation time (6 months) such as homogenous structure, clearness, light yellow color, the smell of thyme and semi – solid consistency. During the measurement of pH values of oleogels, it has been found out that pH values matched human physiological pH value. During the measurement of viscosity of... [to full text]

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