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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.
101

Características bioativas e respostas fisiológicas de amoras-pretas durante maturação e armazenamento / Bioactive characteristics and physiological responses of blackberries during ripening and storage

Celant, Viviane Marcela 30 August 2013 (has links)
Made available in DSpace on 2017-07-10T17:40:43Z (GMT). No. of bitstreams: 1 Viviane_Marcela_Celant_Tese.pdf: 2607659 bytes, checksum: dce48aa66c42bd218c28cf222b91a771 (MD5) Previous issue date: 2013-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The blackberry (Rubus spp.) has high nutritional quality, is rich in vitamin C, carbohydrates, minerals, vitamins A and B, as well as being a source of functional compounds. The blackberry is an excellent source of natural antioxidants, such as anthocyanins and polyphenols. It is a non-climacteric fruit and, due to their physical fragility and high rates of respiration and perspiration, its fruits are highly perishable, this fator becomes limiting your marketing fresh. The objective of this work was to evaluate the bioactive characteristics, physiological and biochemical characteristics of blackberry cultivars during maturation and storage in different packaging. Therefore, three experiments were conducted. The first consisted of evaluating the content of phenolic compounds, flavonoids and anthocyanins, antioxidant capacity and chemical characteristics of aqueous and etanol extracts of the fruits of blackberry cultivars Brazos, Tupy, Arapaho, Choctaw and Guarani. The results showed that 80% ethanol was more efficient in extracting anthocyanins in all cultivars and total flavonoid content was higher in 'Guarani'. The efficiency of sequestration of TEAC and DPPH radical was dependent on the solvent used in the extraction, with higher antioxidant capacity in aqueous and TEAC highest antioxidant capacity in DPPH etanol extracts. Regardless of the extraction solvent, 'Arapaho' had the highest antioxidant capacity. The second experiment evaluated the same parameters of experiment 1, but only in the ethanol extract of the fruit of 'Brazos' and 'Tupy' on maturation of immature, intermediate and mature. 'Brazos' and 'Tupy' showed total phenolic content higher in the immature stage. Antioxidant activity by ABTS method was higher in ripe fruits. The DPPH antioxidant activity was higher in 'Brazos' when immature, 'Tupy' showed similar values to the ABTS assay. Increases in the content of ascorbic acid as the fruit ripening of 'Brazos' and 'Tupy'. In the third experiment also evaluated the same parameters of other experiments, only in etanol solvent, together with the enzymatic activity of fruits of blackberry 'Tupy' , packaged in polyethylene terephthalate and polyvinyl chloride film, and stored for 1 , 4 and 8 days in a refrigerated environment. The weight loss was lower in fruits stored in PET packaging. There were some increases in the content of ascorbic acid in fruits from the 1st to the 4th day in both packages. The DPPH and ABTS antioxidant activity of fruit wrapped in PET was superior to fruits with PVC. Phenolic compounds increased with storage in both packaging used, with the highest levels found in fruits stored in PVC at the end of storage. The anthocyanin contentes were also higher on the 8th day of storage, especially in fruits kept in the PET packaging. At the end of the 8 days of storage the peroxidase activity was higher in fruits stored in PVC, and the activity of phenylalanine ammonia - lyase was higher in fruits packed in PET for all storage periods / A amora-preta (Rubus spp.) apresenta alta qualidade nutricional, é rica em vitamina C, carboidratos, minerais, vitaminas do complexo B e A, além de ser fonte de compostos funcionais. A amora-preta é excelente fonte de antioxidantes naturais, como antocianinas e polifenóis. É um fruto não climatérico e, devido à sua fragilidade física e altas taxas de respiração e transpiração, seus frutos são extremamente perecíveis, fator este que torna limitante a sua comercialização in natura. Assim, o objetivo deste trabalho foi avaliar as características bioativas, respostas fisiológicas e bioquímicas de cultivares de amora-preta durante a maturação e armazenamento em diferentes embalagens. Para tanto, três experimentos foram conduzidos. O primeiro constou da avaliação dos conteúdos de compostos fenólicos, flavonoides e antocianinas totais, da capacidade antioxidante e das características químicas dos extratos aquoso e etanólico dos frutos das cultivares de amora-preta Brazos, Tupy, Arapaho, Choctaw e Guarani. Os resultados mostraram que etanol 80% foi mais eficiente na extração de antocianinas totais para todas as cultivares e o conteúdo de flavonoides totais foi superior em Guarani . A eficiência de sequestro dos radicais TEAC e DPPH foi dependente do solvente utilizado na extração, com maior capacidade antioxidante TEAC nos extratos aquosos e maior capacidade antioxidante DPPH nos extratos etanólicos. Independente do solvente de extração, Arapaho apresentou a maior capacidade antioxidante. No segundo experimento foram avaliados os mesmos parâmetros do experimento 1, porém apenas em extrato etanólico dos frutos de Brazos e Tupy nos estádios de maturação imaturos, intermediários e maduros. Brazos e Tupy apresentaram conteúdos de compostos fenólicos totais mais elevados no estádio imaturo. A atividade antioxidante avaliada pelo método ABTS foi maior em frutos maduros. A atividade antioxidante DPPH foi maior em Brazos quando imaturos, Tupy apresentou valores similares ao ensaio ABTS. Ocorreram aumentos no conteúdo de ácido ascórbico conforme a maturação dos frutos de Brazos e Tupy . No terceiro experimento também foram avaliados os mesmos parâmetros dos demais experimentos, apenas em solvente etanólico, juntamente com a atividade enzimática de frutos de amora-preta Tupy , embalados em embalagens de politereftalato de etileno e filme de policloreto de vinila e armazenados por 1, 4 e 8 dias em ambiente refrigerado. A perda de massa fresca foi menor em frutos armazenados em embalagem PET. Foram verificados acréscimos no conteúdo de ácido ascórbico nos frutos entre o 1° ao 4° dia em ambas as embalagens. A atividade antioxidante DPPH e ABTS dos frutos embalados com PET foi superior aos frutos com PVC. Compostos fenólicos aumentaram significativamente com o armazenamento em ambas as embalagens utilizadas, sendo os maiores teores encontrados para frutos mantidos em PVC ao final do armazenamento. Os teores de antocianinas também foram superiores no 8° dia do armazenamento, principalmente em frutos mantidos em embalagem do tipo PET. Ao final dos 8 dias de armazenamento a atividade de peroxidase foi maior para frutos mantidos em PVC, e a atividade de fenilalanina amônia-liase apresentou-se maior nos frutos embalados em PET para todos os períodos de armazenamento.
102

The Effect of Snow on Plants and Their Interactions with Herbivores.

Torp, Mikaela January 2010 (has links)
The ongoing climate changes are predicted to accelerate fast in arctic regions with increases in both temperatures and precipitation. Although the duration of snow cover is generally expected to decrease in the future, snow depth may paradoxically increase in those areas where a large amount of the elevated precipitation will fall as snow. The annual distribution and duration of snow are important features in arctic ecosystems, influencing plant traits and species interactions in various ways. In this thesis, I investigated the effect of snow on plants and their interactions with herbivores by experimentally increasing the snow cover by snow fences in three different habitats along an environmental gradient in Abisko, northern Sweden. I found that the snow cover mattered for plant quality as food for herbivores and herbivore performance. An enhanced and prolonged snow cover increased the level of insect herbivory on dwarf birch leaves under field conditions. Autumnal moth larvae feeding on leaves that had experienced increased snow-lie grew faster and pupated earlier than larvae fed with leaves from control plots. These findings indicated that plants from snow-rich plots produced higher-quality food for herbivores. My studies showed that differences in snow-lie explained parts of the within-year spatial and seasonal variation in plant chemistry and patterns of herbivory in this arctic landscape. The relationship between leaf nitrogen concentration and plant phenology was consistent between treatments and habitats, indicating that snow per se, via a delayed phenology, was controlling the nitrogen concentration. The relationship between leaf age and level of herbivory was positive in the beginning of the growing season, but negative in the end of the growing season, indicating an increasing importance of plant palatability and a decreasing importance of exposure time in determining the level of herbivory throughout the growing season. The concentrations of phenolics varied among habitats, treatments and sampling occasions, suggesting that these plants were able to retain a mosaic of secondary chemical quality despite altered snow conditions. Furthermore, the nutrient limiting plant growth, according to N:P ratio thresholds, appeared to shift from nitrogen to phosphorus along the topographic gradient from snow-poor ridges to more snow-rich heathlands and fens. Snow addition had, however, no significant effect on other nutrient concentrations than nitrogen and no significant effect on the leaf N:P ratio, indicating that differences in snow cover could not explain the variation in plant nutrient concentrations among habitats. In a five-year study, I found opposing inter-annual effects of increased snow on plant chemistry. In contrast to earlier results, the effect of snow-lie on plant nitrogen concentration was predominantly negative. However, the effect of increased snow cover on the level of herbivory remained predominantly positive. The strong within-year relationship between snow-melt date (via plant phenology) and plant nitrogen concentration and level of herbivory could not predict inter-annual variation in the effect of snow manipulation. I did not find any conclusive evidence for a single factor causing the inter-annual opposing effect of snow addition, but the results indicated that interactions with summer and winter temperatures might be important. In conclusion, this thesis showed that climate-induced changes in snow conditions will have strong effects on plant traits and plant-herbivore interactions. However, alterations in snow cover do not influence all plant traits and the effect may vary in time and space.
103

Effects of Bioactive Compounds from Different Potato Genotypes on Prostate Cancer Development in Athymic Nude Mice

Turner, Sarah 2012 May 1900 (has links)
Phytochemicals are widely noted for their role in chemoprevention. Potato (Solanum tuberosum L.) is the third most important food crop worldwide and is considered a significant source of antioxidants, providing an ideal delivery system for beneficial compounds. The anti-proliferative and pro-apoptotic properties of potato bioactive compounds have been reported in vitro on human prostate cancer cell lines. However, in vivo studies are limited, and more information is needed to determine the chemopreventive properties of potato in the diet. The objective of this study was to evaluate the effects of potato bioactives on prostate cancer in vivo using a mouse model. Athymic nude mice received xenografts of human prostate cancer cells (PC-3) and were administered extracts of potato bioactives from either the white flesh Solanum bulbocastanum (PI243510) or CO112F2-2P/P (purple-flesh Colorado selection), while control mice received water. Neither potato extract provided a significant reduction in tumor growth nor reduced levels of the pro-angiogenic protein VEGF, but the S. bulbocastanum extract reduced expression of metastasis associated protein 1 (MTA1) in tumors, and both potato extracts reduced MTA1 expression in lungs, suggesting the need for further research on the potential chemopreventive or chemotherapeutic properties of potato bioactives.
104

Nutriomic analysis of fresh and processed fruits through the development of an in-vitro model of human digestive system

Ms Indah Epriliati Unknown Date (has links)
Nutriomics is the study of the whole range of nutritional components (nutriome) in foods. In order to further understand the molecular basis for the positive health benefits of fruits identified from epidemiology, the mass balance through the human digestion and absorption should be studied. The components of the nutriome studied in this research were sugars, carotenoids, phenolics and organic acids, all important for defining dietary – human health relationships and linking to evidence obtained from epidemiological studies. An attempt to approach a realistic human mimetic digestion and absorption model has been carried out in this study using a static in-vitro model of the human digestive system. Two major novelities in this model compared to other in-vitro models are (i) the use of particles of solid fruit products that mimic the products of human chewing and (ii) a cell-based (Caco-2) in-vitro intestinal absorption model. Hence, imitative bioavailability, i.e. releasing nutrients and potential levels of target compounds reaching the portal circulatory system could be assessed. The fruits studied were tomato, mango, papaya; each as fresh, dried and juiced forms. In-vivo chewing suggested 0.5 cm size modes for dried products and 1.5 cm for fresh products. The agglomerates that were obtained from the chewing of dried products disaggregated during in-vitro digestions in the presence of acids (gastric simulation) or sodium bicarbonate at pH 6 (small intestinal simulation). The extent of this disaggregation followed the order: tomato > mango > papaya. Although all fresh samples contained separated cells, their responses to a 5 mm texture analysis probe (mimicking teeth cusps) varied depending on fruit products. All matrices were hardened by drying, becoming more brittle and breaking easier to produce smaller size modes. Variation between individual participants in the size of their chewed particles was lower for fresh products and high for dried products. The in-vitro digestion and absorption model developed had simulated particle sizes of approximately 0.5 cm3 for dried products or 1.5 cm3 (thickness varied with the products) for fresh products in a 9:1 ratio mix with blended samples, and were digested in-vitro using the following steps: 1. ‘Chewing’: pH 6.9; 37 C, 10 min, in a shaking-water bath (55 rpm) with human alpha-amylase (100 U/L). 2. ‘Gastric’ digestion: pH 2; 37 C, 60 min, in a shaking-water (55 rpm) with porcine pepsin (40 µg/L). 3. ‘Intestinal’ digestion: pH 6; 37 C, 60 min, in a shaking-water bath (55 rpm) with porcine pancreatin and bile extract (1.4 µg/L and 8.6 µg/L, respectively). 4. Caco-2 cell monolayer in-vitro passages: aged 22 days post confluent monolayers in a 24 transwell-insert well plate seeded at 105 cells, pH 7.4 with renewal of apical and basolateral solutions every 30 min for bioavailability estimations. In this study, two models of basolateral – apical solution renewals were carried out: both apical and basolateral were renewed (model A) and basolateral only was renewed (model B). To study metabolites produced by Caco-2 cells, the bioassays were carried out for 22 h without renewals of apical and basolateral solutions (model C). An overview of nutriomics analysis of in-vitro digestions of mango, papaya and tomato based on principal component analysis (PCA) suggested: (1) fruit types led to variable nutriome releases: in-vitro digestions affected tomato >mango >papaya; (2) processing varied nutriome releases from fruit products with juicing tended to release more nutriome components, whereas drying and unprocessed (fresh) did not show noticeably different patterns; (3) gastric and simultaneous gastric-intestinal digestions were similar in nutriome releases whereas contributions of intestinal digestion alone were negligible for water soluble nutriome components; and overall (4) during in-vitro digestions there were no interactions among releasing nutriome from the fruit products studied (independent nutriome releasing processes). Phenolic components showed molecular changes during in-vitro digestion and processing, due to, heating effects, pH or enzymic degradations. Caco-2 bioassays using model compounds showed a range of monolayer responses as follows: (1) mannitol, lycopene and catechin were strictly retained in the apical solution; (2) sugars, caffeine and atenolol were translocated in the apical-to-basolateral direction as intact molecules; (3) Beta-carotene partially disappeared from the apical solution without basolateral release. Models A – C consistently confirmed these responses. Low recoveries provided evidence for cellular metabolisms of (particularly) phenolic and carotenoid molecules by the Caco-2 cell monolayers.
105

Investigation of environmental staining and storage on discolouration and cooking quality in Faba bean (Vicia faba L.)

Nasar-Abbas, Syed Muhammad January 2007 (has links)
[Truncated abstract] Faba bean (Vicia Faba L.) ranks third worldwide in overall production among coolseason legume crops and is used as a main source of protein both for food and feed purposes in many parts of the world. Australia is a major exporter of faba beans and the price received depends on the quality of the seed especially colour of the seed coat. Consumers don?t like faba beans that are dark coloured or that have blemishes on the seed coat. Environmental staining and storage discolouration deteriorate seed colour causing substantial economic losses to growers and grain handlers. To investigate the influence of environmental conditions, especially during pod/seed development and maturity, on the degree of environmental staining, field trials were conducted using four faba bean varieties (Fiord, Fiesta, Ascot and Cairo) in a range of environmental conditions under the Mediterranean-type climate of south western Australian grain belt. Although a majority of seeds had good colour but 3-25% were stained up to an unacceptable level across the trials and this varied with location and variety. Seeds formed later in plant development (located on the upper nodes of the plant) were more stained than seeds formed earlier (located on the lower nodes). This may be due to end of season environmental factors, such as high temperature and light intensity, and water and nutrient stress. Similarly seeds formed on small and weak plants, which may have developed under stressful conditions, had more staining than seeds formed on normal sized and healthy plants. Genotypic variation was also evident with Fiord showing greater staining than Ascot, Fiesta and Cairo. The cause of environmental staining appears to be complex but was associated with phenolic contents. Storage discolouration was influenced by a number of factors including temperature, seed moisture content, light and storage period and these were critical in determining storage life. ... Faba bean hardness, examined by the hard-to-cook test, also increased with increased storage temperature. There was a high negative correlation (r2 = 0.98) between storage temperature and cooking ability of faba bean. There was a three-fold increase in lignin content of faba bean stored at 50°C compared to those stored at 5°C and it was correlated with bean hardness (r2 = 0.98). Reduction in free phenolics was negatively correlated (r2 = 0.75) with bean hardness. The environmental staining in faba bean can be minimized with correct choice of varieties, robust agronomic practices to establish and maintain healthy plants and the use of mechanical graders and colour sorters. For minimizing storage discolouration faba beans must be dehydrated to ≤12% seed moisture content and stored in insulated bins (silos) or at least bins painted white and constructed under trees shades. In addition occasional flushing with N2 will further help reduce the colour darkening. The above approaches will improve quality, market opportunities, price and hence profitability of faba bean in the farming systems.
106

Développement des produits à haute valeur nutritionnelle à partir de la production du Canna à la Réunion / Development of products with high nutritional value from the production of Canna in Reunion

Hutte, Marie 08 December 2017 (has links)
Canna edulis, une plante amylacée pluriannuelle, de la famille Cannaceae, originaire d'Amérique du Sud, accumule de l'amidon dans son rhizome. L'objectif des travaux de thèse est d'étudier la culture du Canna à La Réunion en fonction des conditions pédoclimatiques et des saisons avec caractérisation de la qualité des rhizomes selon ses stades de développements. Sept parcelles expérimentales sont suivies sur deux sites contrastés : la Plaine des Palmistes et Bassin Plat. Tout au long de la croissance des plants, des données sont enregistrées sur la qualité des sols, la pluviométrie, les températures moyennes, et le rayonnement pour caractériser les sites. Des indicateurs de stades de développements sont suivis pour informer de l'état de maturité des plants et évaluer l'effet des conditions pédoclimatiques sur leur développement. Des échantillonnages réguliers sont réalisés pour caractériser le développement et la composition des rhizomes mais également les propriétés technologiques et intérêts nutritionnels en fonction de leurs maturités. C'est ainsi que des dosages d’amidons, de sucres libres, en lien avec la viscosité et la gélatinisation, de même que les teneurs en composés phénoliques et leur activité antioxydantes, ont été évalués sur plusieurs types de produits intermédiaires : rhizomes lyophilisés, amidons ou fibres alimentaires. Outre son caractère innovant dans le domaine des procédés d'extraction d’amidon à forte valeur ajoutée, la particularité de ce travail de thèse réside dans le fait qu'il s'inscrit dans le cadre plus vaste de mise en place de la filière Canna et de sa valorisation agronomique, technologique et nutritionnelle. / Canna edulis, is a multiannual plant, from the Cannaceae family, originating from South America, that accumulate starch in its rhizome. This thesis work aims to study Canna’s culture on Réunion Island depending on soil, climate and season specificities using rhizome quality changes depending on the plants development stages. Seven experimental crops were followed at two contrasted sites: La Plaine des Palmistes and Bassin Plat. During plant growth, soil quality, rain, mean temperatures and solar radiation data were collected in order to characterize the planting locations. Development stage indicators were monitored to enlighten plants maturity status and evaluate soil and climate effects on their development. Regular samplings were scheduled to characterize the rhizomes development and composition but also their technological properties and nutritional interests as influenced by their maturity. Thus, starch, free sugars, viscosity, gel formation properties as well as phenolics contents and their antioxidant activities were evaluated on several intermediate products namely freeze-dried rhizomes, starches and dietary fibers. Besides its innovative nature on the high-valued starch extraction process field, this thesis particularity relies on the fact that it is integrated in the wide project of Canna culture settlement and its agronomic, technologic and nutritional enhancement.
107

Qualidade de mel de abelha Apis mellifera l natural e após utilizado para alimentação de abelhas Melipona subnitida

Tôrres, Wedson de Lima 11 November 2017 (has links)
Submitted by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-03-27T20:27:33Z No. of bitstreams: 1 WedsonLT_DISSERT.pdf: 1073579 bytes, checksum: 409886291a5814c831107fd57eaf6b1e (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:58:13Z (GMT) No. of bitstreams: 1 WedsonLT_DISSERT.pdf: 1073579 bytes, checksum: 409886291a5814c831107fd57eaf6b1e (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:58:35Z (GMT) No. of bitstreams: 1 WedsonLT_DISSERT.pdf: 1073579 bytes, checksum: 409886291a5814c831107fd57eaf6b1e (MD5) / Made available in DSpace on 2018-06-18T16:58:51Z (GMT). No. of bitstreams: 1 WedsonLT_DISSERT.pdf: 1073579 bytes, checksum: 409886291a5814c831107fd57eaf6b1e (MD5) Previous issue date: 2017-11-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The physicochemical analysis reveals the quality of honeys comparing with standards already established by the Brazilian regulation law. This work aims evaluate the quality mellifera L. honey, collected in regulated and unregulated honey establishments at Sertão do Apodi territory -RN, Northeastern of Brazil, and reevaluate this quality after used as feed for stingless bees Melipona subnitida. The changes made by this stingless bees in the Apis honey was descripted. The honey samples were collected in 2016 and 2017at 22 honey establishments. All the samples were transported to the UFERSA Food Technology Laboratory where the following quality characteristics were evaluated: moisture, pH, free acidity (LA), electrical conductivity (EC), hydroxymethylfurfural (HMF), reducing sugars (SFA), ash content, color, water activity (AW), total phenolics (FT), total flavonoids (FT) and antioxidant activity. The experimental design was randomized The physicochemical composition of Apis mellifera honeys, differ between registered and unregistered honey establishments The Apis honey was modified by the stingless bees on to the following physicochemical parameters: moisture, reducing sugars, ash, insoluble solids, acidity and pH. However, the final characteristics of the modified honey were closer to the honeybees honey.. Unexpectedly, the total phenolic content, flavonoids and antioxidant activity of the modified honey were higher than the natural Melipona honey / As análises físico-químicas revelam a qualidade de méis e compara com os padrões já estabelecidos na legislação. Por ocasião do período de escassez a alimentação artificial para meliponineos é uma técnica fundamental para a manutenção das colmeias em determinadas épocas do ano, Nesse sentido, o presente trabalho teve por objetivo avaliar a qualidade de mel de abelha Apis mellifera L. coletado em casas de méis do território Sertão do Apodi-RN e, após utilizado como alimentação para abelhas Melipona subnitida. O trabalho foi realizado em duas etapas, a primeira consistiu de coletas de mel de Apis mellifera, nos anos de 2016 e 2017 em uma casa certificada de mel e em 22 casas de méis sem certificação no território sertão do Apodi. A segunda etapa consistiu em selecionar seis colônias de Melipona subnitida para alimentação das abelhas com o mel homogeneizado de Apis, resultante da primeira etapa de coleta, e procedeu-se à colheita para análise das mudanças físico-químicas efetuadas pelas abelhas jandaíras. Em todas as etapas, as amostras foram transportadas para o laboratório de Tecnologia de Alimentos da UFERSA onde foram avaliadas as seguintes características de qualidade: umidade, pH, acidez livre (AL), condutividade elétrica (CE), hidroximetilfurfural (HMF), açúcares redutores (AR), sacarose aparente (SAC), sólidos insolúveis (SI), teor de cinzas, cor, atividade de água (AW), fenólicos totais (FT),flavonoides totais (FT) e atividade antioxidante. O delineamento experimental utilizado foi em blocos casualizado. A composição físico-química de amostras de méis de Apis mellifera coletadas nas casas de méis (UEPA) do território sertão do Apodi, diferiram quanto o teor de umidade, cinzas, acidez livre e sacarose. A abelha Melipona subnitida modificou os seguintes padrões físico-químicos do mel de Apis: umidade, açúcares redutores, cinzas, sólidos insolúveis, acidez e pH. Porém, as características finais do mel modificado ficaram mais próximas do mel de Apis mellifera. O conteúdo de fenólicos totais, flavonóides e atividade antioxidante do mel modificado foram superiores ao mel de abelha jandaíra natural / 2018-03-27
108

Cultura de tecidos e análise do potencial antioxidante de Passiflora alata Curtis / Tissue Culture and analysis of antioxidant potential of Passiflora alata Curtis

Danielle Simone de Carvalho Lugato 15 June 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Passiflora alata Curtis, comumente conhecida como maracujá-doce, é uma das espécies do gênero Passiflora cultivadas comercialmente, sendo consumida in natura devido ao seu gosto adocicado. Ela também é utilizada em todo o mundo como ornamental e na medicina popular. O objetivo deste trabalho foi o estabelecimento de diferentes estratégias para a cultura in vitro de P. alata e a análise da produção de substâncias antioxidantes nos materiais obtidos in vitro, em comparação com as plantas in vivo. Diferentes tratamentos visando à quebra da dormência das sementes foram avaliados para a germinação in vitro ou in vivo, além da incubação das sementes sob tipos distintos de luz. Para o estabelecimento das culturas primárias, apices caulinares e segmentos nodais das plântulas derivadas da germinação in vitro foram cultivados em meio MSM . A taxa de alongamento dos brotos e o número de nós por brotos das culturas primárias foram aumentados pela adição de água de coco ao meio. Plantas derivadas dessas culturas foram utilizadas como fontes de explantes nodais, internodais e foliares. O potencial morfogênico de sementes sem tegumento foi também avaliado. Calos friáveis foram induzidos a partir de segmentos nodais e foliares na presença de PIC, e aqueles obtidos a partir de folhas em meio suplementado com PIC a 28,9 μM foram selecionados para o estabelecimento de culturas de células em suspensão. Após o desenvolvimento de diferentes estratégias in vitro para P. alata, folhas de plantas in vivo foram utilizadas para a avaliação de parâmetros que afetam a extração de substâncias antioxidante. O potencial antioxidante foi determinado pelo ensaio DPPH e o conteúdo de fenóis totais foi determinado utilizando o método Folin-Ciocalteau. Após o desenvolvimento do protocolo de extração, a atividade antioxidante dos diferentes materiais in vitro foi também avaliada. A eficiência antirradicalar variou entre os sistemas de cultura estudados, sendo diretamente proporcional ao conteúdo de fenóis totais dos extratos. Esses resultados indicam que as estratégias para cultura in vitro de P. alata desenvolvidas neste trabalho representam alternativas para a multiplicação de plantas e produção de substâncias fenólicas com ação antioxidante. / Passiflora alata Curtis, commonly known as sweet passion fruit, is one of the commercially cultivated species of the genus Passiflora, being consumed in natura due to its sweet taste. It is also used worldwide as an ornamental and in folk medicine. The goal of this work was the establishment of different strategies for in vitro culture of P.alata and the analysis of the production of antioxidant substances by in vitro materials, in comparison with in vivo-grown plants. Different treatments aiming at seed dormancy breakage were evaluated for in vitro or in vivo germination, in addition to the incubation of seeds under distinct types of light. For the establishment of primary cultures, shoot tips and nodal segments excised from plantlets derived from in vitro germination were cultured on MSM . Shoot elongation rate and number of nodes per shoot of the primary cultures were improved by adding coconut water to the medium. Plants derived from these cultures were used as sources of nodal, internodal and leaf explants. The morphogenic potential of decoated seeds was also evaluated. Friable calluses were induced from nodal and leaf segments in the presence of PIC, and those obtained from leaves on medium supplemented with 28.9 μM PIC were selected for the establishment of cell suspension cultures. After the development of different in vitro strategies for P. alata, leaves of in vivo plants were used for the evaluation of the distinct parameters affecting the extraction of antioxidant substances. The antioxidant potential was determined by the DPPH assay and total phenolic content of the extract was determined using the Folin- Ciocalteau method. Following the development of the extraction protocol, the antioxidant activity of the different in vitro materials was also evaluated. The antiradicalar efficiency varied among the culture systems, being directly proportional to the total phenolic content of the extracts. These results indicate that the strategies of in vitro culture of P. alata developed in this study represent an alternative to plant multiplication and production of phenolic substances with antioxidant action.
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METABÓLITOS SECUNDÁRIOS, COMPOSIÇÃO QUÍMICA E ATIVIDADE ANTIOXIDANTE DO ÓLEO ESSENCIAL E DAS FOLHAS DE Vitex megapotamica (SPRENGEL) MOLDENKE / SECONDARY METABOLITES, CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF THE ESSENTIAL OIL AND OF THE LEAVES OF VITEX MEGAPOTAMICA (SPRENGEL) MOLDENKE

Brum, Thiele Faccim de 19 March 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Verbenaceae family consists of about 2600 species, of which the genera Vitex has 250 species. Vitex megapotamica is distributed in northeastern Argentina, eastern Paraguay, in Uruguay and commonly found in southern Brazil. The present work aims to perform a phytochemical study, the chemical composition and antioxidant activity of essential oil and extracts of leaves of V. megapotamica. Leaves of V. megapotamica were collected in Santa Maria, RS, Brazil, in december of 2010. A dried voucher specimen is preserved in the herbarium of the Department of Biology at Federal University of Santa Maria by register number SMBD 13071. The material was macerated in ethanol (70%) and filtered, after a part of the ethanol extract was reserved and the other evaporated in rotary evaporator to remove ethanol (aqueous extract). This was partitioned in ampoules of separation using increasingly polar solvents: dichloromethane, ethyl acetate and butanol, and the crude extract was obtained by drying the aqueous extract. The phytochemical study revealed the presence of anthocyanins, phenols, tannins, catechins, flavonols, flavanones, flavanonóis, xanthones, triterpenoids, steroids, cardioactive glycosides, phenols with ortho and meta position free, coumarins and organic acids. The crude extract and fractions were investigated for antioxidant activity by the method of DPPH, TBARS and protein carbonyls, the content of phenolic compounds (flavonoids, polyphenols and tannins) was determined, and was performed to identification and quantification of phenolic acids by HPLC. The phenolics compounds were higher in the ethyl acetate fraction, being 522.4 ± 12.1 mg/g for polyphenols and 220.48 ± 0.30 mg/g for flavonoids, only this fraction showed condensed tannins, though in small quantity. The assays with DPPH revealed high radical scavenging capacity, showed IC50 ranged from 14.17 ± 0.76 μg/ml to 37.63 ± 0.98 μg/ml. The crude extract and fractions inhibited the TBARS production, with IC50 ranging from 16.36 ± 5.09 μg/ml to 72.72 ± 7.22 μg/ml, where as ethyl acetate fraction was showed the best result. The extracts were effective in inhibiting protein carbonyls at concentrations of 50, 100 and 200 mg/ml, therefore have a higher amount of phenolic compounds. HPLC analysis revealed the presence of chlorogenic and rosmarinic acids and the second in the greatest quantity. Through the extracting the essential oil of the leaves, it was obtained the chemical composition and antioxidant capacity by DPPH method. The main components in the oil were BHT (34.17%), phytol (12.66%), α-caryophyllene (11.84%), δ-elemene (10.65%), β-caryophyllene (7.82%), γ-elemene (4.24%) and germacrene D (2.82%). The oil showed percentage inhibition of 35.62% and 75.25% at concentrations of 76 and 101.6 mg/ml, respectively. Probably, the antioxidant activity reported is due to the major component of BHT. Through this study it was possible identify the chemical composition of essential oil, as well as know the major groups of substances present in extracts from leaves of V. megapotamica who obtained a good antioxidant activity. / A família Verbenaceae consiste de aproximadamente 2600 espécies, sendo que o gênero Vitex apresenta 250 espécies. Vitex megapotamica distribui-se no nordeste da Argentina, no leste do Paraguai, no Uruguai e comumente encontrada no sul do Brasil. O presente trabalho teve como objetivo realizar um estudo fitoquímico, a constituição química e a atividade antioxidante do óleo essencial e dos extratos das folhas de V. megapotamica. As folhas da planta foram coletadas no município de Santa Maria, RS, Brasil, em dezembro de 2010. O material está depositado no herbário do Departamento de Biologia da UFSM catalogado sob o número de registro SMBD 13.071. O material macerado com etanol (70%) e filtrado, após uma parte do extrato etanólico foi reservada e a outra evaporada em evaporador rotatório para remoção do etanol (extrato aquoso). Este foi particionado em ampolas de separação, utilizando solventes de polaridade crescente: diclorometano, acetato de etila e butanol, sendo que o extrato bruto foi obtido pela secura do extrato aquoso. O estudo fitoquímico revelou a presença de heterosídeos antociânicos, fenóis, taninos, catequinas, flavonóis, flavanonas, flavanonóis, xantonas, esteroides, triterpenoides, heterosídeos cardioativos, fenóis com posição orto e meta livres, cumarinas, e ácidos orgânicos. O extrato bruto e as frações foram investigados quanto à capacidade antioxidante através do método do DPPH, TBARS e carbonilação de proteínas, o teor de compostos fenólicos (flavonoides, polifenóis e taninos) foi determinado, e foi realizada a identificação e quantificação de ácidos fenólicos por CLAE. Os teores de compostos fenólicos foram maiores na fração acetato de etila, sendo de 522,4 ± 1,12 mg/g para polifenóis e 220,48 ± 0,30 mg/g para flavonoides, esta fração foi a única que apresentou taninos condensados, embora em pequena quantidade. Os ensaios com DPPH revelaram alta capacidade seqüestradora de radicais livres, apresentando IC50 que variaram de 14,17 ± 0,76 μg/ml a 37,63 ± 0,98 μg/ml. As frações e o extrato bruto inibiram a produção de TBARS, com IC50 que variou de 16,36 ± 5,09 μg/ml a 72,72 ± 7,22 μg/ml, sendo que a fração acetato de etila foi a que apresentou o melhor resultado. Os extratos foram eficazes na inibição da carbonilação de proteinas em concentrações de 50, 100 e 200 mg/ml, por possuírem maior quantidade de compostos fenólicos. A análise por CLAE revelou a presença de ácido clorogênico e rosmarínico, sendo o segundo encontrado em maior quantidade. Através da extração do óleo essencial das folhas, foi possível obter a composição química e a capacidade antioxidante pelo método do DPPH. Os componentes majoritários obtidos foram BHT (34,17%), fitol (12,66%), α-cariofileno (11,84%), δ-elemeno (10,65%), β-cariofileno (7,82%), γ-elemeno (4,24%) e germacreno D (2,82%). O óleo mostrou inibição percentual de 35,62% e 75,25% em concentrações de 76 e 101,6 mg/ml, respectivamente. Provavelmente, a atividade antioxidante relatada se deve ao componente majoritário BHT. Através deste estudo, foi possível identificar a composição química do óleo essencial bem como reconhecer os principais grupos de substâncias presentes nos extratos das folhas de V. megapotamica os quais obtiveram uma boa atividade antioxidante.
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Propriedades fungicida e antioxidante de extratos vegetais

Takao, Leandro Kenji 30 March 2015 (has links)
Made available in DSpace on 2016-06-02T19:30:12Z (GMT). No. of bitstreams: 1 6721.pdf: 2764879 bytes, checksum: ca82bcb193d5ae0d2e21032afd6ed1dd (MD5) Previous issue date: 2015-03-30 / Financiadora de Estudos e Projetos / The Brazilian savanna holds the richest flora among the tropical savannas, being one of the hot spots for conservation of the biodiversity in the world. However, the chemical potential of its plant species is still underused while deforestation and loss of biodiversity are main issues. In the Brazilian savanna, plants are exposed to environmental pressures (competition, pathogens, drought, injurious UV radiation, etc) that may stimulate the production of secondary metabolites as a defense. These compounds can generally be explored due to their biological properties. The aim of this study was to assess the fungicidal and antioxidant properties of plants from the Brazilian savanna. First a screening was conducted with ethanolic leaf extracts of 28 plant species. There was no activity against Alternaria alternata, a filamentous fungi that causes one of the most severe diseases in tangerines (Alternaria brown spot disease). However, the same extracts presented a high antioxidant potential associated with the phenolic content. Other investigations were made using infusion extractions focusing on the Myrtaceae family, one of the most abundant families of plants in the Brazilian savanna. Most species also presented high antioxidant activity and phenolic content. At last, the extraction of piceid, a compound with high antioxidant activity, was optimized from roots of Psidium laruotteanum. A response surface methodology was applied to assess the influence of solvent, pH, amplitude, cycle, temperature and solvent-solid ratio using an ultrasound extraction. A high amount of piceid was extracted and Psidium laruotteanum root was found to be the most concentrated source of this compound reported up to date. These results point the plant species from the Brazilian savanna as an important source of bioactive compounds, emphasizing the need to preserve and study its biodiversity. / O cerrado possui a flora mais rica entre as savanas tropicais, sendo um dos pontos quentes para conservação da biodiversidade no mundo. No entanto, o potencial químico de suas espécies vegetais é ainda subutilizado, enquanto o desmatamento e a perda de biodiversidade são questões de grande relevância. No cerrado, as plantas estão expostas a pressões ambientais (competição, patógenos, seca, radiação UV nociva, etc) que podem estimular a produção de metabólitos secundários como defesa. Estes compostos geralmente podem ser explorados devido suas propriedades biológicas. O objetivo deste estudo foi avaliar as propriedades fungicidas e antioxidante de plantas do cerrado. Primeiro uma triagem foi realizada com extratos etanólicos de folhas de 28 espécies vegetais. Não houve nenhuma atividade contra Alternaria alternata, um fungo filamentoso que causa uma das doenças mais severas em tangerinas (mancha marrom de Alternaria). No entanto, os mesmos extratos apresentaram um potencial antioxidante elevado associado com o conteúdo fenólico. Outras investigações foram feitas usando extrações por infusão enfocando a família Myrtaceae, uma das famílias mais abundantes de plantas no cerrado. A maioria das espécies apresentou alta atividade antioxidante e alto conteúdo fenólico. Por fim, a extração de piceido, um composto com alta atividade antioxidante, foi otimizada de raízes de Psidium laruotteanum. Uma metodologia de superfície de resposta foi aplicada para avaliar a influência do solvente, pH, amplitude, ciclo, temperatura e razão solvente-sólido usando uma extração de ultrasonido. Uma alta quantidade de piceido foi extraída e a raiz de Psidium laruotteanum se mostrou como sendo a fonte mais concentrada deste composto relatada até hoje. Estes resultados apontam as espécies de plantas do cerrado como uma importante fonte de compostos bioativos, enfatizando a necessidade de preservar e estudar sua biodiversidade.

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