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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.
1

Studies of chemical constituents on the aerial parts of pelargoniumcapitatum

Mthembu, Zandile Lorraine January 2017 (has links)
>Magister Scientiae - MSc / Pelargonium capitatum is a plant that is popular in essential oils. The isolated essential oil constituents from the flowers and leaves of the plant were obtained by hydrodistillation followed by GC-MS analysis. The following essential constituents were obtained in abundance from flowers and leaves 8, 11-octadecadienoic acid and citronellol, caryophyllen, α-cubebene, copaene, azulene, pentacosane, 9, 12- octadecadienoic acid. Crude extracts from Pelargonium capitatum were fractionated through various chromatographic techniques in order to achieve satisfactory separations. Four compounds were characterized and the structural elucidation were unambiguously confirmed by spectroscopic methods including one and two-dimensional nuclear magnetic resonance and high resolution mass spectroscopy. The compounds were isolated from the ethyl acetate (2) and hexane (2) extracts, respectively. The four isolates were identified as quercetin, quercetin xylopyranoside, β-sitosterol and undecaprenol. The isolate and the different extracts were tested for cytotoxicity using brine shrimp lethality test. The results showed that quercetin and the extracts were active with hexane extract showed the highest cytotoxicity level of 1.5μg/ml. To the best of our knowledge quercetin xylopyranoside, β-sitesterol and undecaprenol compounds are reported for the first time from Pelargonium capitatum.
2

Extraction et purification de substances naturelles : comparaison de l’extraction au CO2-supercritique et des techniques conventionnelles / Extraction and purification of natural substances : comparison of supercritical CO2 extraction and conventional techniques

Herzi, Nejia 21 March 2013 (has links)
Ce travail concerne l'extraction de substances naturelles d'origine végétale en utilisant des procédés « verts » tels que l'extraction au CO2 supercritique (CO2-SC, de 90 à 1000 bar) et l'extraction à l'eau sub-critique (SWE). Ces procédés sont une alternative à l'hydrodistillation (HD) et l'extraction par solvant (SE) traditionnellement utilisés dans l'industrie des produits naturels. La majorité du travail a été réalisée sur l'espèce Tetraclinis articulata où les performances des procédés, CO2-SC , HD, SWE et SE, ont été optimisées puis comparées en termes de rendement, composition chimique, durée…, et en particulier activité antioxydante des extraits (évaluée par les tests ABTS+ and DPPH). La plus forte activité antioxydente a été mise en évidence pour les extraits CO2-SC, ceci étant très probablement dû à une moindre dégradation thermique, comme l'a indiqué la comparaison des compositions chimiques. La CO2-SC basse pression (90 bar) a permis d'obtenir un extrait de bonne qualité et, pour ce cas, une modélisation a été proposée pour comprendre et identifier le mécanisme limitant qui s'est avéré être l'équilibre solide-fluide. La modélisation de l'hydrodistillation a également été proposée, basée sur le modèle de Sovová . Ensuite, l'approche a été étendue à d'autres plantes : Eucalyptus cinerea, Eucalyptus Camaldulensis, Cypres sempervirens et callitris. / This work has dealt with extraction of natural substances from plants using « green » processes such as supercritical CO2 extraction (CO2-SC from 90 to 1000 bar) and extraction with subcritical water (SWE). These processes are an alternative to hydrodistillation (HD) and solvent extraction (SE) traditionally used in the natural products industry. Main part of the work was done on the species Tetraclinis articulata, and performance of the different processes, CO2-SC, HD,SWE and SE, were optimized and compared in terms of yield, chemical composition, duration ... and especially antioxidant activity of extracts (assessed by the ABTS+ and DPPH tests). CO2-SC extracts exhibited the strongest antioxidant activity and comparison of chemical compositions of the different extracts indicated that this is very probably due to lower thermal degradation of active molecules. For low pressure CO2-SC (90 bar), a model was proposed to understand and identify the limiting mechanism that proved to be solid-fluid equilibrium. For hydrodistillation, modelling, based on the Sovová 's model was also proposed. Then, the approach was extended to other plants: Eucalyptus cinerea and Eucalyptus camaldulensis, Cypres sempervirens and Callitris.
3

Inventaire et analyse chimique des exsudats des plantes d'utilisation courante au Congo-Brazzaville / Inventory and chemical analysis of exsudates from plants commonly used in the republic of Congo-Brazzaville

Elouma Ndinga, Arnold Murphy 27 February 2015 (has links)
Les exsudats des plantes sont des substances naturelles complexes. Ils sont utilisés par plusieurs populations d’Afrique et trouvent de nombreuses applications : en thérapeutique, en pharmacie galénique, en parfumerie, etc. Au Congo, une grande majorité de ces substances est encore mal connue. Ce travail de thèse a consisté à inventorier les plantes à exsudats du Congo et à mettre au point une méthodologie d’analyse physico-chimique permettant la caractérisation des exsudats d’arbres d’origine botanique certifiée.La méthodologie d’inventaire adoptée nous a permis de recenser 135 plantes à exsudats appartenant à 87 genres. Il en ressort de cette étude que les exsudats des plantes inventoriées ont multiples usages (glu, insectifuge, allume-feu, antidouleur, etc.).La stratégie mise en place pour leur caractérisation fait appel à plusieurs techniques analytiques (SPIR, SMIR, CPG-SM, GCxGC-MS) et de traitement d’échantillon (Hs-SPME, hydrodistillation, extraction au Soxhlet, silylation, méthylation, pyrolyse). Dans le cadre de ce travail deux exsudats ont été caractérisés. L’exsudat de D. edulis (G. Don) K.J. Lam qui est constitué de monoterpènes hydrocarbonés et de triterpènes, dont les majeurs sont : 3-épi-α et -β-amyrine. L’exsudat de G. demeusei (Harms) J. Léonard dont la fraction volatile est constituée essentiellement de sesquiterpènes et la fraction peu-volatile d’acides diterpéniques de type labdane (acide éperuique, cativique, copalique, ozique, etc.).Pour exploiter l’efficacité de séparation élevée de la GCxGC-MS, nous nous sommes confronté aux problèmes de la non-répétabilité des cartes chromatographiques obtenues en 2D. Nous avons alors mis en place une méthodologie permettant de vérifier l’épaisseur de film et l’homogénéité des dépôts de phases stationnaires afin de sélectionner des colonnes courtes identiques pour la GCxGC. Cependant, les résultats préliminaires ont montré que même avec des colonnes de deuxième dimension identiques, on pouvait avoir des différences au niveau de carte 2D. / Plant exudates are natural complex substances. They are used by several populations in Africa and have many applications: in therapeutics, in galenic pharmacy, in perfumery, etc. In Congo, a great majority of these substances are not yet well known. This thesis work aimed to make an inventory of plant exudates from Congo and to develop a methodology for performing physico-chemical analysis which may enable characterization of exudates from botanical certified trees.Through the methodology that we developed, 135 plant exudates belonging 87 genera were registered. It was observed in this study that these exudates are used for many purposes (glue, insect repellent, making fire, anti-pain, etc).The strategy implemented for characterizing the exudates included several analytical (SNIR, SMIR, GC-MS, GCxGC-MS) and sample processing (Hs-SPME, hydrodistillation, extraction using the Soxhlet, silylation, methylation pyrolyse) techniques. With regard to this work, two exudates were characterized. The exudates from D. edulis (G. Don) K.J. Lam which contained monoterpene hydrocarbons and triterpenes, with the major constituents being: 3-epi-α and -β-amyrine. The exudates from G. Demeusei (Harms) J. Léonard was found to have the sesquiterpenes as major constituents of the volatile fraction and the labdane-type diterpenes (eperuique acide, cativique acid, copalique acid, ozique acid, etc) as major constituents of the poor-volatile fraction.To explore the efficacy of elevated separation of the GCxGC-MS, we faced some problems related to the non-repeatability of chromatographic cards obtained in 2D. Therefore, we put in place a methodology which enables us to verify the film thickness and homogeneity of layers of stationary phases in order to select identical short columns for GCxGC. However, the preliminary results have shown that even using second identical dimension columns, we could observed differences in 2D cards
4

Eco-Extraction des huiles essentielles et des arômes alimentaires en vue d'une application comme agents antioxydants et antimicrobiens / Eco Extraction of essential oils and aromas for their use as antioxydants and antimicrobials

Mnayer, Dima 09 December 2014 (has links)
Les huiles essentielles et les arômes des plantes constituent un réel potentiel pour l’industrie dans le but de substituer aux composés synthétiques ayant des effets néfastes sur la santé et l’environnement. Afin de contribuer aux principes de la chimie verte, cette étude porte sur l’éco-extraction et la valorisation des extraits naturels des plantes et le développement d’une nouvelle technologie «verte» pour l’extraction des composés aromatiques naturels. La première partie de ce manuscrit mets en évidence les propriétés biologiques des huiles essentielles et des arômes et l’importance de leurs applications dans différents domaines surtout le domaine agroalimentaire. Dans la deuxième partie, les études sur les propriétés biologiques des huiles essentielles des plantes des Alliacées montrent leurs bonnes activités antioxydantes et antimicrobiennes. Ces résultats encourageants ont permis dans la troisième partie de valoriser les sous-produits d’oignon issus de la turbo hydrodistillation et qui sont considérés normalement comme déchets. La technique offre une bonne extraction des composés phénoliques et des flavonoïdes utilisant l’eau comme solvant naturel. La quatrième et la dernière partie de ce travail s’est orientée vers l’optimisation et le développement d’une technologie « verte» utilisant les ultrasons et l’huile de tournesol comme solvant naturel pour l’extraction des composés aromatiques du thym. Cette nouvelle approche écologique permet l’extraction des absolues dépourvues de cire et des résidus de solvants pétroliers, contenant la teneur la plus élevée en thymol et exerçant la plus forte activité antioxydante. / Plant essential oils and aromas are a real potential for the industry to substitute the synthetic compounds that might have harmful effects on the human health and the environment. In order to contribute to the green chemistry principles, this study focuses on the “eco-extraction” and valorization of natural plant extracts and the development of a new «green» technology for the extraction of aromatic compounds. The first part of this manuscript highlights the biological properties of the essential oils and aromas and the importance of their applications in various sectors especially in the food industry. In the second part, studies on the biological properties of the essential oils from plants of the Alliaceae family show their good antioxidant and antimicrobial activities. These encouraging results have allowed in the third part to evaluate the onion by-products resulting from the turbo hydrodistillation, which are normally considered as waste. The technique offers a good extraction of flavonoids and phenols using water as natural solvent. The fourth and final part of this work deals with the optimization and the development of a «green» technology using ultrasound and sunflower oil as a natural solvent for the extraction of aromatic compounds from thyme. This new ecological approach allows the extraction of absolutes free from waxes and petroleum solvent residues, having the highest content in thymol and exerting the strongest antioxidant activity.
5

The composition, geographical variation and antimicrobial activity of Mentha longifolia subspecies polyadena (Lamiaceae) leaf essential oils

Petkar, Sahir Yusuf 26 September 2008 (has links)
Mentha longifolia subsp. polyadena was collected from seven localities in South Africa and from a single population in Botswana to study the essential oil composition and antimicrobial activity of this ethnomedicinal plant. The essential oils were obtained by hydrodistillation and analysed by gas chromatography coupled to mass spectroscopy (GC/MS) and a cluster analysis was performed on the essential oil dataset. From eight samples (representing eight natural populations), two major chemotypes were identified: (i) a menthofuran rich type (51.4% - 61.6%); and (ii) a cis-piperitone epoxide (14.7% – 35.7%) and piperitenone oxide (14.6% - 65.7%) rich type. The constituent analysis showed quantitative variation with higher amounts of oxygencontaining monoterpenes ranging from 56.5% to 89.6% whilst the sesquiterpene hydrocarbons ranged from 4.4% to 16.7%. The essential oil from the different localities mostly showed moderate to good antimicrobial activity against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Moraxella catarrhalis, Yersinia enterocolitica and Enterococcus faecalis. The oils were generally inactive against Escherichia coli and Salmonella typhimurium. Candida albicans and Cryptococcus neoformans indicated highest sensitivities for oil samples from Komukwane (3 mg/ml and 0.5 mg/ml respectively) and Prins Albert (0.5 mg/ml and 1.6 mg/ml respectively). The HPLC profiles of the methanol and chloroform (1:1) extracts were more conservative and less variable compared to the essential oils. Two major peaks corresponding to retention times of 22.39 min and 26.47 min were present in all eight samples. Most of the solvent extracts displayed moderate to good antimicrobial activity against Gram-positive pathogens, in particular against S. aureus, S. epidermidis and B. cereus with MIC values ranging from 0.5 mg/ml to 2 mg/ml in most cases. The extracts also demonstrated moderate to good activity against most of the Gram-negative pathogens, in particular against Y. eneterocolitica and M. catarrhalis, with MIC values ranging from 0.5 mg/ml to 2 mg/ml. These results may in part provide scientific evidence for the extensive use of Mentha longifolia in traditional healing.
6

Extração assistida por micro-ondas de óleo essencial de folhas de eucalipto (eucalyptus urophylla x globulus)

Ribeiro, Leticia Gouveia January 2018 (has links)
A celulose das árvores do gênero Eucalyptus é um dos principais elementos de interesse econômico desse vegetal. Suas folhas, apesar de conter óleo essencial (OE), caracterizam-se como um subproduto da indústria de processamento de papel e celulose. Assim, pesquisas com relação à recuperação dessa biomassa tornam-se importantes, principalmente, do ponto de vista ambiental e econômico. Tradicionalmente, a extração de OEs ocorre pelo processo de hidrodestilação (HD), o qual necessita de longos tempos de extração. Visando superar essa restrição, a tecnologia de extração assistida por micro-ondas (Microwave Assisted Extraction - MAE) vem sendo desenvolvida e aplicada. O objetivo principal deste estudo foi avaliar o processo de extração de OE de folhas de eucalipto, empregando os métodos de extração HD e MAE. Para esse processo em escala de bancada, desenvolveu-se um aparato de extração por meio da adaptação de um forno micro-ondas doméstico. Inicialmente, analisou-se o rendimento de OE das matrizes de subprodutos de folhas de eucalipto das espécies Eucalyptus saligna, E. urohpylla e E. urophylla x globulus geradas a partir de uma indústria de celulose. Os resultados apontaram que a espécie E. urophylla x globulus apresentou maior teor de OE (2,16±0,02%), sendo a espécie escolhida para a aplicação da tecnologia MAE. Na segunda etapa do estudo, fez-se uma avaliação dos efeitos dos fatores do processo MAE, avaliando os fatores razão sólido:solvente (1:1; 1:1,5 e 1:2), potência do micro-ondas (680, 850 e 1.020 W) e tempo de extração total (20, 40, 60 min) no rendimento de OE. Desse modo, as condições ideais do processo foram determinadas como: razão sólido:solvente de 1:2, potência de 680 W e tempo de extração total de 60 minutos. Para essas condições, realizou-se o estudo cinético e modelagem matemática com a avaliação dos modelos de primeira ordem, segunda ordem, Peleg e Patricelli. No estudo cinético, o tempo total do processo MAE para a obtenção do rendimento de 1,8±0,1% foi apenas 60 minutos, tempo 57% inferior ao observado no método HD para igual rendimento (140 minutos). Dentre os modelos cinéticos estudados, o modelo de Patricelli foi o que apresentou melhor ajuste aos dados experimentais da extração HD (R² igual 0,9904 e RMSE igual 0,0016) e da extração MAE (R² igual 0,9962 e RMSE igual 0,0006). Por fim, as análises energéticas e de impacto ambiental também indicaram o método MAE como uma tecnologia mais ambientalmente amigável do que a HD, tornando-se atrativa para o setor industrial. Com base nos resultados obtidos, pode-se concluir que a extração de OE da matriz estudada proporcionou a reutilização de um subproduto industrial, sugerindo uma alternativa de exploração e agregando valor ao mesmo. / The cellulose from trees of the genus Eucalyptus is the main industrial product of this species. Its leaves, although containing essential oil (EO), are characterized as a by-product from the pulp and paper processing industry. Thus, researches about the recovery of this biomass are important, mainly from the environmental and ecological point of view. Traditionally, the extraction of EO occurs by hydrodistillation (HD), process that requires long extraction times. In order to overcome this restriction, microwave assisted extraction (MAE) has been developed and applied. The main objective of this study was to evaluate the extraction process of eucalyptus EO, using the HD and MAE methods. For this laboratory-scale process, an extraction apparatus was developed through the adaption of a domestic microwave oven. Initially, the yield of EO by-products of eucalyptus leaves of the species Eucalyptus saligna, E. urophylla and E. urophylla x globulus from a cellulose industry were analyzed. The results showed that the species E. urophylla x globulus presented the highest EO content (2.16 ± 0.02%), being the species chosen for the application of the MAE technology. In the second stage of the study, an evaluation of the effects of MAE process factors was performed, analyzing the factors ratio solid:solvent (1:1, 1:1,5 and 1:2), microwave power (680, 850 and 1.020 W) and total extraction time (20, 40, 60 min) in the EO yield. Thus, the ideal process conditions were determined as: ratio solid:solvent of 1:2, power of 680 W and total extraction time of 60 minutes. For these conditions, a kinetic study and a mathematical modeling were performed evaluating the first-order, second-order, Peleg and Patricelli models. In the kinetic study, the total time of the MAE process to obtain the yield of 1.8 ± 0.1% was only 60 minutes, 57% lower than the HD method for the same yield (140 min). Among the kinetic models studied, the Patricelli model presented the best fit to the experimental data of the HD extraction (R² equal to 0.9904 and RMSE equal to 0.0016) and MAE extraction (R² equal to 0.9962 and RMSE equal to 0.0006). Finally, the energy and environmental impact analyzes also indicated the MAE method more environmentally friendly than HD, being attractive for the industrial sector. Based on the results, it is possible to conclude that the extraction of EO from the studied matrix provided the reuse of an industrial by-product, suggesting an exploration alternative adding value to this residue.
7

Extração assistida por micro-ondas de óleo essencial de folhas de eucalipto (eucalyptus urophylla x globulus)

Ribeiro, Leticia Gouveia January 2018 (has links)
A celulose das árvores do gênero Eucalyptus é um dos principais elementos de interesse econômico desse vegetal. Suas folhas, apesar de conter óleo essencial (OE), caracterizam-se como um subproduto da indústria de processamento de papel e celulose. Assim, pesquisas com relação à recuperação dessa biomassa tornam-se importantes, principalmente, do ponto de vista ambiental e econômico. Tradicionalmente, a extração de OEs ocorre pelo processo de hidrodestilação (HD), o qual necessita de longos tempos de extração. Visando superar essa restrição, a tecnologia de extração assistida por micro-ondas (Microwave Assisted Extraction - MAE) vem sendo desenvolvida e aplicada. O objetivo principal deste estudo foi avaliar o processo de extração de OE de folhas de eucalipto, empregando os métodos de extração HD e MAE. Para esse processo em escala de bancada, desenvolveu-se um aparato de extração por meio da adaptação de um forno micro-ondas doméstico. Inicialmente, analisou-se o rendimento de OE das matrizes de subprodutos de folhas de eucalipto das espécies Eucalyptus saligna, E. urohpylla e E. urophylla x globulus geradas a partir de uma indústria de celulose. Os resultados apontaram que a espécie E. urophylla x globulus apresentou maior teor de OE (2,16±0,02%), sendo a espécie escolhida para a aplicação da tecnologia MAE. Na segunda etapa do estudo, fez-se uma avaliação dos efeitos dos fatores do processo MAE, avaliando os fatores razão sólido:solvente (1:1; 1:1,5 e 1:2), potência do micro-ondas (680, 850 e 1.020 W) e tempo de extração total (20, 40, 60 min) no rendimento de OE. Desse modo, as condições ideais do processo foram determinadas como: razão sólido:solvente de 1:2, potência de 680 W e tempo de extração total de 60 minutos. Para essas condições, realizou-se o estudo cinético e modelagem matemática com a avaliação dos modelos de primeira ordem, segunda ordem, Peleg e Patricelli. No estudo cinético, o tempo total do processo MAE para a obtenção do rendimento de 1,8±0,1% foi apenas 60 minutos, tempo 57% inferior ao observado no método HD para igual rendimento (140 minutos). Dentre os modelos cinéticos estudados, o modelo de Patricelli foi o que apresentou melhor ajuste aos dados experimentais da extração HD (R² igual 0,9904 e RMSE igual 0,0016) e da extração MAE (R² igual 0,9962 e RMSE igual 0,0006). Por fim, as análises energéticas e de impacto ambiental também indicaram o método MAE como uma tecnologia mais ambientalmente amigável do que a HD, tornando-se atrativa para o setor industrial. Com base nos resultados obtidos, pode-se concluir que a extração de OE da matriz estudada proporcionou a reutilização de um subproduto industrial, sugerindo uma alternativa de exploração e agregando valor ao mesmo. / The cellulose from trees of the genus Eucalyptus is the main industrial product of this species. Its leaves, although containing essential oil (EO), are characterized as a by-product from the pulp and paper processing industry. Thus, researches about the recovery of this biomass are important, mainly from the environmental and ecological point of view. Traditionally, the extraction of EO occurs by hydrodistillation (HD), process that requires long extraction times. In order to overcome this restriction, microwave assisted extraction (MAE) has been developed and applied. The main objective of this study was to evaluate the extraction process of eucalyptus EO, using the HD and MAE methods. For this laboratory-scale process, an extraction apparatus was developed through the adaption of a domestic microwave oven. Initially, the yield of EO by-products of eucalyptus leaves of the species Eucalyptus saligna, E. urophylla and E. urophylla x globulus from a cellulose industry were analyzed. The results showed that the species E. urophylla x globulus presented the highest EO content (2.16 ± 0.02%), being the species chosen for the application of the MAE technology. In the second stage of the study, an evaluation of the effects of MAE process factors was performed, analyzing the factors ratio solid:solvent (1:1, 1:1,5 and 1:2), microwave power (680, 850 and 1.020 W) and total extraction time (20, 40, 60 min) in the EO yield. Thus, the ideal process conditions were determined as: ratio solid:solvent of 1:2, power of 680 W and total extraction time of 60 minutes. For these conditions, a kinetic study and a mathematical modeling were performed evaluating the first-order, second-order, Peleg and Patricelli models. In the kinetic study, the total time of the MAE process to obtain the yield of 1.8 ± 0.1% was only 60 minutes, 57% lower than the HD method for the same yield (140 min). Among the kinetic models studied, the Patricelli model presented the best fit to the experimental data of the HD extraction (R² equal to 0.9904 and RMSE equal to 0.0016) and MAE extraction (R² equal to 0.9962 and RMSE equal to 0.0006). Finally, the energy and environmental impact analyzes also indicated the MAE method more environmentally friendly than HD, being attractive for the industrial sector. Based on the results, it is possible to conclude that the extraction of EO from the studied matrix provided the reuse of an industrial by-product, suggesting an exploration alternative adding value to this residue.
8

Estudo fitoquímico do óleo essencial dos frutos da aroeira (Schinus terebinthifolius Raddi) e sua eficácia no combate ao dengue / Phytochemistry study of the essential oil of the Brazilian Peppertree fruits (Schinus terebinthifolius Raddi) and its effectiveness combating dengue

Cole, Eduardo Roberto 07 March 2008 (has links)
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9

Controle alternativo da antracnose durante a pós-colheita de goiabas "Paluma" simulando armazenamento e a comercialização

Oliveira, Lucas Fonseca Menezes 25 April 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Brazil is one of the largest producers of fruit, guava with the culture of great importance in the diet of the population by having large amounts of vitamins, and carbohydrates and carotenoids. The postharvest of guava can be regarded as a problem for the broader participation of Sergipe in the marketing of this fruit in other parts of the country. The alternative control of fungal diseases plays an important role in the search for the most demanding consumer markets for healthy products and known origin. Thus the objective of this study was to develop and refine a technique that allows the storage of guavas for prolonged periods without the use of agrochemicals and excellent post-harvest quality in order to reduce costs and increase food security. Through the process of hydrodistillation essential oil was obtained from seeds of Shinus terebinthifolius from seeds and leaves and it was verified the oil yield in different periods of distillation and a period of 2.5 h distillation recommended for this plant. This had its chemical composition determined by analysis by gas chromatography, the components found in greater quantity in the oil were: ρ-Menth-1-en-9-ol, α-Thujene, β-pinene, Camphene, α - Fenchene , Terpinen-4-ol acetate, Bornyl Acetate, Cariophilene, Terpinen-4-ol, α-Terpineol, Germacrene - D, δ-cadinene, Hedycariol, α - Gurjunene, α-eudesmol, β-eudesmol. Petri dishes containing PDA culture medium supplemented with different concentrations of essential oil of S. terebinthifolius were inoculated with mycelial structures of the fungus Colletotrichum gloeosporioides for determining the lowest inhibitory concentration (MIC) of the oil on the mold where there is an efficiency of approximately 47% for controlling fungus at concentrations of 2%, 3%, 4%, 5% oil in the culture medium, as recommended concentration of 2% of essential oil in vivo tests. Guava fruit harvested at mature were inoculated with the fungus that causes anthracnose and treated with essential oil of aroeira da praia 3% being placed in low temperature (15 °C) and temperature (25 °C) in order to assess the period of storage and marketing guava and the development of the fungus against the essential oil. There was loss of weight in fruit and little variation in the amounts of soluble solids during the storage period. The guavas were already significant loss of firmness on the 5th day of storage. Significant change in the peel and pulp of guava during storage was an expected behavior for this variety of guavas. The essential oil delayed the appearance of characteristics of anthracnose lesions 3 days compared with the fungicide used in the experiment. It was demonstrated the accumulation of proline in the guavas during the post-harvest, indicating that the accumulation of proline may be related to weight loss and the development of anthracnose in guavas. / O Brasil é um dos maiores produtores mundiais de frutas, tendo a cultura da goiabeira grande importância na alimentação da população por apresentar grandes quantidades de vitaminas, além de carboidratos e carotenóides. A pós-colheita da goiaba pode ser considerada como um problema para a ampliação da participação de Sergipe na comercialização desta fruta em outras regiões do país. O controle alternativo de doenças fúngicas assume papel importante na busca de mercados consumidores mais exigentes por produtos saudáveis e de procedência conhecida. Desta forma o objetivo deste trabalho foi desenvolver e aprimorar uma técnica que possibilite o armazenamento de goiabas por períodos prolongados, sem o uso de agroquímicos e com excelente qualidade pós-colheita, de forma a reduzir os custos e aumentar a segurança alimentar. Pelo processo de hidrodestilação foi obtido o óleo essencial de sementes de aroeira da praia sendo verificado o rendimento do óleo em diversos períodos de destilação sendo o período de 2,5h de destilação o recomendado para essa planta. Esse que teve a sua composição química determinada através de análise em cromatógrafo gasoso. Os componentes encontrados em maior quantidade no óleo foram: ρ-Menth-1-em-9-ol, α-Thujene, β-Pinene, Camphene, α Fenchene, Terpinen-4-ol acetate, Bornyl Acetate, Cariophilene, Terpinen-4-ol , α-Terpineol, Germacrene D, δ-Cadinene, Hedycariol, α Gurjunene, α-Eudesmol, β-Eudesmol. Em placas de Petri contendo meio de cultura BDA acrescido de diversas concentrações do óleo essencial de aroeira da praia foram depositadas estruturas miceliais do fungo Colletotrichum gloeosporioides para a determinação da menor concentração inibitória (MCI) do óleo, onde se verificarou uma inibição de aproximadamente 47% no desenvolvimento do fungo nas concentrações de 2%, 3%, 4%, 5% do óleo no meio de cultura, sendo recomendada a concentração de 2% de óleo essencial para testes in vivo. Frutos de goiabeira colhidos fisiologicamente maduros foram inoculados com o fungo causador da antracnose e tratados com óleo essencial de aroeira da praia 3% sendo acondicionados em baixa temperatura (15 °C) e temperatura ambiente (25 °C) com o intuito de avaliar o período de armazenamento e comercialização da goiaba e também o desenvolvimento do fungo frente o óleo essencial. Verificou-se perda de massa fresca nos frutos e pouca variação nos valores de sólidos solúveis durante todo o período de armazenamento. As goiabas apresentaram perda de firmeza significativa já no 5° dia de armazenamento. Houve alteração significativa na coloração da casca e da polpa das goiabas durante o armazenamento, comportamento já esperado para essa variedade de goiaba. O óleo essencial retardou o surgimento de lesões características da antracnose em 3 dias quando comparado com o fungicida utilizado no experimento. Foi comprovado o acúmulo de prolina nas goiabas durante o período de pós-colheita, o que pode ter relação com a perda de massa fresca e com o desenvolvimento da antracnose em goiabas.
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Extração assistida por micro-ondas de óleo essencial de folhas de eucalipto (eucalyptus urophylla x globulus)

Ribeiro, Leticia Gouveia January 2018 (has links)
A celulose das árvores do gênero Eucalyptus é um dos principais elementos de interesse econômico desse vegetal. Suas folhas, apesar de conter óleo essencial (OE), caracterizam-se como um subproduto da indústria de processamento de papel e celulose. Assim, pesquisas com relação à recuperação dessa biomassa tornam-se importantes, principalmente, do ponto de vista ambiental e econômico. Tradicionalmente, a extração de OEs ocorre pelo processo de hidrodestilação (HD), o qual necessita de longos tempos de extração. Visando superar essa restrição, a tecnologia de extração assistida por micro-ondas (Microwave Assisted Extraction - MAE) vem sendo desenvolvida e aplicada. O objetivo principal deste estudo foi avaliar o processo de extração de OE de folhas de eucalipto, empregando os métodos de extração HD e MAE. Para esse processo em escala de bancada, desenvolveu-se um aparato de extração por meio da adaptação de um forno micro-ondas doméstico. Inicialmente, analisou-se o rendimento de OE das matrizes de subprodutos de folhas de eucalipto das espécies Eucalyptus saligna, E. urohpylla e E. urophylla x globulus geradas a partir de uma indústria de celulose. Os resultados apontaram que a espécie E. urophylla x globulus apresentou maior teor de OE (2,16±0,02%), sendo a espécie escolhida para a aplicação da tecnologia MAE. Na segunda etapa do estudo, fez-se uma avaliação dos efeitos dos fatores do processo MAE, avaliando os fatores razão sólido:solvente (1:1; 1:1,5 e 1:2), potência do micro-ondas (680, 850 e 1.020 W) e tempo de extração total (20, 40, 60 min) no rendimento de OE. Desse modo, as condições ideais do processo foram determinadas como: razão sólido:solvente de 1:2, potência de 680 W e tempo de extração total de 60 minutos. Para essas condições, realizou-se o estudo cinético e modelagem matemática com a avaliação dos modelos de primeira ordem, segunda ordem, Peleg e Patricelli. No estudo cinético, o tempo total do processo MAE para a obtenção do rendimento de 1,8±0,1% foi apenas 60 minutos, tempo 57% inferior ao observado no método HD para igual rendimento (140 minutos). Dentre os modelos cinéticos estudados, o modelo de Patricelli foi o que apresentou melhor ajuste aos dados experimentais da extração HD (R² igual 0,9904 e RMSE igual 0,0016) e da extração MAE (R² igual 0,9962 e RMSE igual 0,0006). Por fim, as análises energéticas e de impacto ambiental também indicaram o método MAE como uma tecnologia mais ambientalmente amigável do que a HD, tornando-se atrativa para o setor industrial. Com base nos resultados obtidos, pode-se concluir que a extração de OE da matriz estudada proporcionou a reutilização de um subproduto industrial, sugerindo uma alternativa de exploração e agregando valor ao mesmo. / The cellulose from trees of the genus Eucalyptus is the main industrial product of this species. Its leaves, although containing essential oil (EO), are characterized as a by-product from the pulp and paper processing industry. Thus, researches about the recovery of this biomass are important, mainly from the environmental and ecological point of view. Traditionally, the extraction of EO occurs by hydrodistillation (HD), process that requires long extraction times. In order to overcome this restriction, microwave assisted extraction (MAE) has been developed and applied. The main objective of this study was to evaluate the extraction process of eucalyptus EO, using the HD and MAE methods. For this laboratory-scale process, an extraction apparatus was developed through the adaption of a domestic microwave oven. Initially, the yield of EO by-products of eucalyptus leaves of the species Eucalyptus saligna, E. urophylla and E. urophylla x globulus from a cellulose industry were analyzed. The results showed that the species E. urophylla x globulus presented the highest EO content (2.16 ± 0.02%), being the species chosen for the application of the MAE technology. In the second stage of the study, an evaluation of the effects of MAE process factors was performed, analyzing the factors ratio solid:solvent (1:1, 1:1,5 and 1:2), microwave power (680, 850 and 1.020 W) and total extraction time (20, 40, 60 min) in the EO yield. Thus, the ideal process conditions were determined as: ratio solid:solvent of 1:2, power of 680 W and total extraction time of 60 minutes. For these conditions, a kinetic study and a mathematical modeling were performed evaluating the first-order, second-order, Peleg and Patricelli models. In the kinetic study, the total time of the MAE process to obtain the yield of 1.8 ± 0.1% was only 60 minutes, 57% lower than the HD method for the same yield (140 min). Among the kinetic models studied, the Patricelli model presented the best fit to the experimental data of the HD extraction (R² equal to 0.9904 and RMSE equal to 0.0016) and MAE extraction (R² equal to 0.9962 and RMSE equal to 0.0006). Finally, the energy and environmental impact analyzes also indicated the MAE method more environmentally friendly than HD, being attractive for the industrial sector. Based on the results, it is possible to conclude that the extraction of EO from the studied matrix provided the reuse of an industrial by-product, suggesting an exploration alternative adding value to this residue.

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