Woody plant encroachment is one of the major problems worldwide because it affects negatively the herbaceous layer, which provide forage for livestock production. However, the role of ruminants particularly browsers in the dispersal of woody plant seeds still remains a concern for farmers interested in grass production. Seedpods of various woody plant species constitute a crucial part of the diet of herbivores during the dry season because of their high nutritional quality compared to herbaceous material. The interaction of associated diet quality, seed characteristics and animal species among other factors play a pivotal part in the success of livestock faecal seeds dispersion. Furthermore, dispersed seeds that successfully grow into mature woody plants become an important source of protein for herbivores. The use of woody plants as a source forage is known to be limited by plant secondary metabolites (PSMs) such as condensed tannins. The objectives of this study were to determine 1) the effects of condensed tannins and crude protein of Vachellia tortilis and Dichrostachys cinerea pods in seed recovery and germination fed to goats, and 2) the effects of diet mixing on the feed intake of plant species by goats. In the first experiment, a total of 12 female indigenous goats and 12 female Pedi sheep were utilised in this study, with the average body weights of 29.50 kg ± 1.60 (S.E) and 28.70 kg ± 1.60, respectively. Twelve goats were grouped into two groups of six goats per group, one group was fed D. cinerea pods and the other group was fed V. tortilis pods. The group of 12 sheep were divided similarly, the one group was fed D. cinerea pods and the other group was fed V. tortilis pods. Each animal was given V. tortilis and D. cinerea pods at 2.50% of their body weight. All animals were allowed to consume D. cinerea or V. tortilis pods within 24 h, after which the remaining pods were collected and weighed. Faecal collection commenced immediately after the 24 h pods feeding and was carried on until no seeds were discovered in faeces. All faeces extracted from sheep and goats were collected daily in the morning from the faecal bags. In the second experiment, a total of 24 indigenous goats with average body weight of 26.6 kg ± 0.51 were utilised. Goats were arbitrarily selected and grouped into four groups of six goats per group (goats were placed individually in 2 m2 pens). Each group was fed one of the following diets: diet one - Searsia lancea, diet two - S. pyroides, diet three - Euclea crispa and diet four - was a combination of the three plant species (Searsia lancea, S. pyroides and Euclea crispa). Searsia lancea, S. pyroides and E. crispa branches were collected every morning prior to feeding, and were weighed before offering the animals. Refusals were gathered and weighed, and intake was calculated as distinction between weight in and refusals. Plant species foliage were analysed for crude protein, condensed tannin, acid detergent lignin, acid detergent fibre and neutral detergent fibre. During the first experiment, the cumulative percentage seed recovery of V. tortilis from goats (46.00 % ± 1.90) and sheep (52.00 % ± 2.93) was significantly higher than D. cinerea from goats (13 % ± 1.47) and sheep (24.00 % ± 1.16). Germination percentage of D. cinerea seeds that passed through the gastro-intestinal tract of goats (33.12 % ± 2.94) and sheep (36.00 % ± 2.68) was significantly higher than V. tortilis seeds that passed through the gastro-intestinal tract of goats (28.98 % ± 2.68) and sheep (23.04 % ± 2.81). Average D. cinerea (34.56 % ± 1.99) and V. tortilis (26.02 %± 2.10) seeds that went through the gastro-intestinal of goats and sheep had a significantly higher germination rate than the control (i.e. no passage through the gut; D. cinerea = 2.31 % ± 1.55, V. tortilis = 5.07 % ± 2.68). The high mean cumulative percentage seed recovery of V. tortilis (18.80 %) may be attributed to the relatively higher crude protein than D. cinerea (12.20 %). This may encourage animal seed dispersal and germination of woody plant species with relatively high crude protein content. In the second experiment, Searsia lancea contained 8.50 % CP, 21.46 % acid detergent fibre (ADF), 12.50 % ADL and 39.37 % NDF. Searsia pyroides had 9.03 % CP, 27.07 % ADF, 10.89 % ADL and 40.30 % NDF. Euclea crispa had 6.19 % CP, 26.20 % ADF, 16.63 % ADL and 30.02 % NDF. Mixed diet (combination of the three plant species) had 8.96 % CP, 23.72 % ADF, 11.13 % ADL and 38.28 % NDF. Searsia lancea had 2.70 % of CTs while S. pyroides had 5.20 % CT, E. crispa had 6.44 % CT and mixed diet had 7.20 % CT. The mean dry matter intake varied significantly among dietary groups (P < 0.001). Similarly, goats offered a mixed diet consumed more CTs (P < 0.01) than those offered individual forage species. The high mean cumulative percentage seed recovery of V. tortilis may be attributed to the higher crude protein of V. tortilis (18.80 %) than D. cinerea (12.20 %). Higher passage rate may encourage animal seed dispersal and germination of plant species. The results from experiment two support the postulation that animals foraging in mixed diet systems consume more PSMs and achieve higher dry matter intake than animals confined to monocultures or single species feeding systems. Given that woody plant encroachment is already reducing farm-grazing capacities in African savannas and this problem is predicted to double by 2050, strategies that improve herbivore ability to consume woody plants will increase forage availability and inform bush control programmes and policies. Moreover, the concomitant increase in CTs by goats exposed to diets with diverse species also has positive implications for animal / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

As folhas de Maytenus ilicifolia são amplamente utilizadas na medicina tradicional brasileira no tratamento de distúrbios gástricos. Após a comprovação de sua eficácia e segurança, a referida droga vegetal tem sido objeto de diversos estudos com a finalidade de estabelecer parâmetros para o controle de qualidade. Neste sentido, foi avaliada a viabilidade do desenvolvimento de um método analítico fundamentado na precipitação de taninos empregando povidona como agente seqüestrante. Os dados revelaram que a remoção de taninos em solução é satisfatória quando empregada a povidona insolúvel. Foi observado que o polímero também é capaz de precipitar outros polifenóis além dos taninos presentes na solução extrativa de M. ilicifolia. Entretanto, as interações do polímero ocorrem preferencialmente com os derivados catéquicos. Adicionalmente foi desenvolvido e validado um método por CLAE para separação e quantificação de catequina e epicatequina em produtos derivados de M. ilicifolia. Não foram detectadas variações nas áreas dos picos ou nos tempos de retenção durante os ensaios de avaliação do método, sugerindo que as condições cromatográficas empregadas são satisfatórias. Para viabilizar a preparação de produto seco por aspersäo (PSA) em torre de secagem piloto munida de aspersor rotatório, foi necessária a concentração da solução extrativa. A operação foi realizada sob pressão reduzida até alcangar um teor de sólidos mínimo de 15 % (m/m). A operação de secagem da solução concentrada apresentou rendimento de 90 % e o PSA obtido apresentou partículas esféricas, com superfície rugosa e tamanho médio de 22,5 um. A caracterização tecnológica do material revelou que as suas propriedades tecnológicas, tais como, densidades, compressibilidade e fluxo, foram incrementadas quando comparados com o produto preparado em equipamento de bancada. Entretanto, estas modificações não foram suficientes para viabilizar sua compressão direta. Assim sendo, o material foi compactado em máquina de comprimir e em rolos para produção de grânulos. A análise do perfil compressional do PSA e dos granulados, empregando o modelo de Heckel, revelou que o aumento da força de compactação durante a operação de granulação foi o principal responsável pela diminuição no potencial de deformação plástica dos grânulos. Como conseqüência, a recompressão dos grânulos em máquina de comprimir originou compactos com dureza inferior àqueles preparados diretamente do complexo farmacêutico. Enquanto o PSA apresentou reduzida tendência ao rearranjo particular nos estágios iniciais da compressão, os grânulos sofreram intensa reacomodação decorrente da fragmentação e formação de novas pontes, assumindo comportamento plástico em pressões de compressão mais elevadas. Por fim, comprimidos contendo teor elevado de granulado de PSA foram preparados utilizando como adjuvantes a celulose microcristalina, o dióxido de silício coloidal e a croscarmelose sódica. A influência da concentração de dióxido de silício coloidal e croscarmelose sódica na formulação, sobre as respostas de dureza, friabilidade e tempo de desintegração dos comprimidos foram avaliadas através de um Desenho Composto Central. Os dados experimentais foram analisados estatisticamente, utilizando os modelos matemáticos para gerar superfícies de resposta. Os resultados indicaram que a concentração de dióxido de silício coloidal foi inversamente relacionada às respostas de dureza e friabilidade, enquanto que a concentração de croscarmelose sódica foi a principal responsável pela redução no tempo de desintegração. As condições ótimas foram selecionadas através da sobreposição dos gráficos, buscando uma formulação com menor tempo de desintegração, menor friabilidade e o máximo de dureza. A formulação eleita deve conter 1,2 % (m/m) de dióxido de silício coloidal e 5,0 % (m/m) de croscarmelose sódica. Nestas condições os comprimidos apresentaram dureza de 107,9 N, friabilidade de 0,56 % (m/m) e desintegração máxima em 6,8 min. / The leaves of Maytenus ilicifolia are widely used within the traditional Brazilian medicine due to its properties against gastric disorders. Once proved its efficacy and safety, this vegetable drug has been the object of several studies to establish the basis for quality control. Taking this into consideration, it was necessary to evaluate the feasibility of developing an analytical method based on the precipitation of tannins, by using polyvinylpyrrolidone for precipitation. The data have shown that the removal of the tannins in solution was successful when insoluble polyvinylpyrrolidone was used. Hereby it was observed that the polymer has also the ability to precipitate other polyphenols besides the tannins from the aqueous solution of M. ilicifolia. However, the interactions of the polymer happened mostly with the condensed tannins. Further it was developed and also validated an HPLC method to separate and quantify catechin and epicatechin present in aqueous extracts of M. ilicifolia. No significant variations of peak areas or retention times were observed when the evaluation of the method was executed, showing satisfactory chromatographic conditions. In order to make a spray dried extract (SDE) using a spray-drier fitted out with a rotary atomizer, it was necessary to concentrate the extractive solution. This operation had been performed under reduced pressure until a content of 15 % solids was achieved. The drying of the concentrated solution lead to a yield of 90 %, and the obtained SDE presented spherical particles, which have a rough surface and a mean particle size of 22,51.1.m. The technological characterization of the SDE showed that attributes such as densities (tap and bulk), compressibility and flow, have been improved when compared to the product prepared using a mini spray-drier supplied with a pneumatic nozzle. However, these modifications were not enough to enable its direct compression. Therefore, the material was compacted to produce granules after slugging or roller compaction, The compressional analysis of the SDE and each granule batch using the Heckel equation proved that the increase in the compaction force once processing the granulation was the main factor to reduce the material's ability to undergo plastic deformation. Consequently, the recompression of the granules in a tablet press led to compacts with a lower crushing strength compared to that prepared by direct compression of the pharmaceutical complex. Whereas the SDE has shown a reduced tendency to particle rearrangement at early stage of compression, the granules showed an intense fragmentation and rebound behavior, presenting a plastic behavior when higher compaction pressures were used. Finally, tablets containing a high dose of granulated spray dried extract of M. ilicifolia were prepared by using the following excipients: microcrystalline cellulose (filler/binder), colloidal silicon dioxide (glidant and moisture adsorber) and cross-linked carboxymethylcellulose (disintegrant). The influences of colloidal silicon dioxide (CSD) and cross-linked carboxymethylcellulose (CMC-Na) on the tablet hardness, disintegration time and friability were evaluated by a central composite design. The data were analyzed statistically and mathematical models were used to create response surfaces. The results have indicated that the concentration of CSD shows an inverse relation to the responses of hardness and friability, while the concentration of CMC-Na was the most important factor that caused a reduction of the time necessary for total disintegration. The optimal conditions for processing were chosen by the overlapping of graphics, taking into consideration that the formulation should present a minimum of disintegration time, lower friability and a maximum of hardness. Thus, it was found that the best formulation should have a content of 1.2% (w/w) of CSD and 5.0% (w/w) of CMC-Na. Regarding these conditions, the tablets have shown a hardness of 107.9 N, friability of 0.56% (w/w) and a disintegration time of 6.8 min.

Made available in DSpace on 2014-07-29T16:16:39Z (GMT). No. of bitstreams: 1 _Aline.pdf: 618371 bytes, checksum: ecf62a99883726fd7690a0fa0b2bedf6 (MD5) Previous issue date: 2008-08-15 / The work aimed to achieve the kinetic study of the physical and chemical characteristics of the pulp baru, through physical and chemical analyses, with focus on tannins, for 6 months of storage. We used two treatments, washing fruits of barus with and without sanitation, both stored in plastic boxes with circulating air, clean and a place under the sun and at room temperature. The proximate composition of the pulp baru occurred in two stages: beginning and end of the study. There was fortnightly analyses in the first 45 days and then of forty-five to forty-five days, for 6 months. It was evaluated in the pulp content of tannins, total and reducing sugars, color and proof of rancidity, and the whole fruit weight and size; addition to microbiological analyses of pulp at each time of storage. There was also a sensory analysis of acceptance of dry biscuit, with and without the replacement of 25% for wheat flour by pulp baru, three times of storage. The results were analyzed using analysis of variance (ANAVA) and Tukey's test (P<0.05). In compositions centesimals observed that the levels of moisture and fibre increased significantly (P<0.05) at the end of the study, while the level of lipids decreased significantly (P<0.05) and the content of protein has remained equal. The levels of reducing sugars and totals have increased over the period of storage. To this total sugar content increased from 22.70% to 47.02% and 23.18% to 48.18% for pulp washing with and without sanitation, respectively. We have increased significantly reducing sugars (P<0.05) over the storage more than 2.5 times for the two parameters evaluated. The content of tannins decreased until the third time, since there is more of that component to the 46 days of storage. It was found that the stage of hygiene caused a decrease in the level of tannins, giving the fruit pulp with hygiene always a lower value for this compound, conversely to what happened with the color of the raw material. The physical parameters of fruit showed no significant differences (P>0.05) to the end of the study. The survey showed that store barus in hygienic conditions increases the shelf life of the flesh of the fruit. / Este trabalho teve o objetivo de realizar o estudo cinético das características físicas e químicas da polpa do baru, por meio de análises físico-químicas, com especial enfoque nos taninos, durante 6 meses de estocagem. Foram utilizados dois tratamentos, frutos de barus sanitizados e sem sanitização, ambos armazenados em caixas plásticas com circulação de ar, e em lugar limpo, ao abrigo do sol e em temperatura ambiente. A composição centesimal da polpa de baru ocorreu em dois tempos: início e fim do estudo. Realizou-se análises quinzenais nos primeiros 45 dias e, posteriormente, de quarenta e cinco em quarenta e cinco dias, durante 6 meses. Avaliou-se na polpa o teor de taninos, açúcares redutores e totais, cor e prova de rancidez; e no fruto inteiro peso e tamanho; além das análises microbiológicas das polpas em cada tempo de estocagem. Realizou-se ainda uma análise sensorial de aceitação de biscoito seco, sem e com a substituição de 25% da farinha de trigo pela polpa de baru, de três tempos de armazenamento. Os resultados foram analisados utilizando análise de variância (ANAVA) e teste de Tukey (P<0,05). Nas composições centesimais observou-se que os teores de umidade e de fibras aumentaram significativamente (P<0,05) ao final do estudo, enquanto que o teor de lipídios diminuiu significativamente (P<0,05) e o teor de proteínas manteve-se igual. Os teores de açúcares redutores e totais foram aumentando ao longo do período de estocagem. Para açúcares totais esse teor aumentou de 22,70% para 47,02% e de 23,18% para 48,18%, para polpas sanitizadas e sem sanitização, respectivamente. Já os açúcares redutores aumentaram significativamente (P<0,05) ao longo da estocagem mais de 2,5 vezes para os dois parâmetros avaliados. O teor de taninos diminuiu até o terceiro tempo, já não existindo mais desse componente aos 46 dias de armazenamento. Verificou-se que a etapa de sanitização provocou uma diminuição no teor de taninos, apresentando as polpas dos frutos sanitizados sempre um valor menor para este composto, inversamente ao que aconteceu com a cor dessa matéria-prima. Os parâmetros físicos dos frutos não apresentaram diferenças significativas (P>0,05) ao fim do estudo. A pesquisa realizada demonstrou que armazenar barus, em condições higiênicas aumenta a vida de prateleira da polpa do fruto.

The aim of this experiment was to determine in vitro the composition, the antibacterial, antioxidant and tanning activity of grape by-products (Vitis vinifera) for its exploitation in the poultry industry. The crude fiber content of the pomace of 31, 6% and for lignin of the seeds it was 61,2%. The pressed seeds contained 13,4% of crude oil, whose composition of fat acid has 67,73% of linoleic acid. To be studied as growth promoter of birds, polar compound had been extracted from the defatted grape seed in a solution with acetone: water: acid ascetic, resulting in 10,3% of extract from the defatted grape seed extract (ESUD) that, when analyzed, evidenced the presence of anthocyanic pigments and condensed tannins. The ESUD presented high antibacterial activity against strains of S. aureus and E. coli, but not against Salmonella sp. The antioxidant activity of the ESUD presented a percentage of inhibition of 1,1-difenil-2-picrilhidrazila comparable to the ascorbic acid, whose effect reached its maximum at 200 μg/ml. The capacity of tannins to bind protein was considered low for the seed and SUD and high for the ESUD. Later on, the inclusion effect of the grape seed and by-product as additives in the diets of poultry upon growth performance had been evaluated for apparent digestibilidade of the dry matter (CDMS), organic matter (CDMO) and crude protein (CDPB), blood levels of cholesterol, triglycerides, total proteins and glucose, beyond cecal pH. Six hundred day old Ross chicks were distributed in completely randomized design, from 1 to 21 days of age, with six treatments, five repetitions of 10 birds, inoculated or not with strains of E. coli, constituting a 6x2 factorial. Initial feed was used constituting the following treatments: T1-negative control; T2-positive control-0.05% of flavomycin and colistin sulphate; T3-0,04% extract of ESUD; T4-0,1% of grape seed (SUI); T5-0,47% of SUI and T6-2,35% of SUI. The inclusion of grape by-products did not influence the rates growth parameters, apparent digestibilidade or cholesterol levels but decrease levels of blood triglycerides. The inoculation decreased body weight, the weight gain, decreased the levels of blood total protein, and increased triglycerides and glucose and when associated with the ESUD, improved the CDMO. The contradictory results indicate the need for further experiments. / O objetivo deste trabalho foi determinar in vitro a composição centesimal, a atividade antibacteriana, antioxidante e tanante de subprodutos da uva (Vitis vinifera) para seu aproveitamento na indústria avícola. O conteúdo de fibra bruta do bagaço foi de 31,6% e de lignina das sementes foi de 61,2%. As sementes prensadas renderam 13,4% de óleo bruto, cuja composição de ácidos graxos tem 67,73% de ácido linoléico. Para serem estudados como aditivos em dietas para aves compostos polares foram extraídos da semente de uva desengordurada numa solução com acetona: água: ácido acético, resultando em 10,3% de rendimento de extrato de semente de uva desengordurada (ESUD) que, quando analisado, evidenciou a presença de taninos condensados e pigmentos antociânicos. O ESUD apresentou atividade antibacteriana alta contra cepas de S. aureus e E. coli mas não contra Salmonella sp. A atividade antioxidante do ESUD apresentou um percentual de inibição do 1,1-difenil-2- picrilhidrazila comparável ao ácido ascórbico, cujo efeito atingiu seu máximo em concentrações de 200μg/ml. A capacidade de complexar proteínas dos taninos foi considerada baixa para a semente e a SUD e alta para a ESUD. Posteriormente foram avaliados os efeitos da inclusão de subprodutos da uva como aditivos nas dietas de frango de corte sobre variáveis de desempenho zootécnico e digestibilidade aparente da matéria seca (CDMS), matéria orgânica (CDMO) e proteína bruta (CDPB), níveis plasmáticos de colesterol, triglicerídeos, proteínas totais e glicose, além de pH cecal. Foram utilizados 600 pintos de corte machos Ross, de 1 a 21 dias de idade, distribuídos em delineamento inteiramente casualizado, com seis tratamentos, cinco repetições de 10 aves, inoculados ou não com cepas de Escherichia coli, constituindo um fatorial 6x2. Utilizou-se ração inicial para a criação constituindo os seguintes tratamentos: T1-controle negativo; T2-0,05% de flavomicina e sulfato de colistina-controle positivo; T3-0,04% ESUD; T4-0,1% de semente de uva integral (SUI); T5-0,47% de SUI e T6-2,35% de SUI. A inclusão de subprodutos da uva não influenciou as variáveis zootécnicas, coeficientes de digestibilidade, nem as taxas de colesterol, mas diminuiu os níveis de triglicerídeos plasmáticos. A inoculação piorou o peso final, o ganho de peso, diminuiu os níveis plasmáticos de proteínas totais, aumentou triglicerídeos e glicose e quando associada com o ESUD melhorou o CDMO. Os resultados contraditórios indicam a necessidade de novos experimentos.

La composition phénolique du vin rouge détermine fortement sa qualité: couleur, goût, texture et la plupart des bienfaits pour la santé. Les conditions ambiantes de la vigne modulent l'équilibre hormonal endogène et l'expression de gènes qui contrôlent la voie de synthèse des composés flavonoïdes, en déterminant la composition phénolique finale du raisin. Même s'ils ont été étudiés, les effets des applications des régulateurs de croissance végétale sur l'équilibre hormonal endogène et la qualité du raisin, les effets de ces substances sur la composition et la qualité du vin sont pauvrement documentés. Le traitement des raisins destinés à la vinification avec des régulateurs de croissance végétale est un outil potentiel pour modifier la qualité des raisins et du vin rouge. Ce projet de thèse a pour objectif d’étudier l’impact d'applications de régulateur de croissance végétale sur la composition phénolique des raisins de Vitis vinifera L. cépages Cabernet Sauvignon et Carménère. L’acide abscissique, l’acide indole-3-acétique et l'acide 2-chloroethilphosphonique ont été appliqués à divers stades phénologiques du raisin, doses et conditions environnementales: Les essais ont été menés à Maipo et Cachapoal au Chili et à Bordeaux en France, dans des vignobles commerciaux et expérimentaux ainsi que sur des plantes cultivées en pots. Il a été examiné l'effet de ces traitements sur le contenu interne d'hormones, sur l'expression de gènes structuraux et régulateurs de la synthèse de composés flavonoides et sur la qualité des raisins, en particulier la composition phénolique de sa pellicule. De plus, des vinifications ont été réalisées à partir de raisins traités pour déterminer l'effet des traitements sur la composition chimique et phénolique du vin, ainsi que sur des attributs qualitatifs tels que les arômes et la texture des vins, jugés par un panel d'évaluation sensorielle. / Phenolic composition strongly determines red wine quality: color, taste, texture and most health benefits. Vineyard environmental conditions modulate endogenous hormonal balance and gene expression which control the flavonoid biosynthetic pathway leading to final grape phenolic composition. Even when the effects of plant growth regulator applications on grape endogenous hormonal balance and quality have been studied, the effect of these substances on wine composition and quality is poorly documented. The treatment of wine grapes with plant growth regulators is a potential tool in order to modify red wine phenolic composition and quality. This thesis project describes six experiments on plant growth regulator applications on developing grapes of Vitis vinifera L., cvs Cabernet Sauvignon and Carménère. Abscisic acid, Indole-3-acetic acid and 2-chloroethylphosphonic acid were applied in different phenological stages, doses and environmental conditions: Maipo and Cachapoal regions in Chile and Bordeaux region in France, commercial and experimental vineyards and plants in containers. The effect on changes in the internal hormonal content, expression of flavonoid biosynthetic and regulatory genes and grape quality, in particular grape skin phenolic composition were examined. In addition, winemaking was performed in order to assess the effect of treatments on wine chemical and phenolic composition and on wine aroma and texture attributes judged by a sensory panel.

Tannine sind pflanzliche, polyphenolische Sekundärmetabolite mit Protein-präzipitierenden und –bindenden Kapazitäten, welche offenbar für die antinutritiven und gesundheitsschädlichen Wirkungen der Tannine verantwortlich sind. Jedoch dominieren in der Literatur die gesundheitsfördernden Beschreibungen, für die meist die antioxidative Kapazität verantwortlich gemacht wurde. Der etablierte Modelorganismus Caenorhabditis elegans wurde zur Analyse dieses Kontrastes ausgewählt. Zunächst wurden Lebensdauer und Stressresistenz der mit Tanninsäure und den Tanninbausteinen Gallussäure, Ellagsäure und Catechin behandelten Nematoden ermittelt. Das vermutete Vorliegen eines „Calorie Restriction“ (CR)-Effektes als auch einer hormetischen Dosis-Wirkungs-Beziehung wurde überprüft. Weiterhin wurden antimikrobielle und antioxidative Eigenschaften als potentielle Ursachen der Langlebigkeit untersucht und die Auswirkungen auf die Fitness und Genexpression analysiert. Die Einbeziehung verschiedener Alterungs-Theorien rundete die Analyse der Tanninwirkung ab. Alle Tannin-Substanzen konnten eine Lebensverlängerung erwirken, doch erstaunlicherweise erwiesen sich Langlebigkeit und Stressresistenz als individuelle, nicht zwangsläufig gekoppelte Parameter. Hormesis, CR-nachahmende Eigenschaften, antimikrobielle Kapazitäten als auch verschiedene stressrelevante Gene sind teilweise für die Lebensverlängerung verantwortlich. Die antioxidative Kapazität scheint jedoch irrelevant zu sein. Die differentielle Expression mehrerer hundert Gene durch Tanninsäure unterstreicht zudem die Komplexität der Wirkweise. Hinweise zur Bestätigung der „Disposable Soma Theory“, der „Mitohormesis“-Theorie und der „Green Theory of Ageing“ konnten zum Teil gefunden werden. Diese Arbeit zeigt die individuelle und kontrastreiche Wirksamkeit der Tannine auf. Sie unterstreicht, dass Tannine molekulare Regulatoren sind, welche nicht nur auf ihre antioxidative und antinutritive Kapazität reduziert werden sollten. / The polyphenolic tannins are plant-produced secondary metabolites with protein precipitating and binding capacities. This characteristic is seemingly responsible for antinutritional and harmful effects. However, health benefits have also been extensively described in the literature. Indeed, antioxidant properties are believed to be the reason for these beneficial effects. The established model organism Caenorhabditis elegans was chosen to examine this apparent contradiction. The nematodes were exposed to tannic acid and to the tannin building blocks gallic acid, ellagic acid, and catechin and the lifespan and stress resistance were determined. The presence of a calorie restriction (CR) effect and a hormetic dose-response-relationship was verified. Furthermore, antimicrobial and antioxidative capacities were assessed as possible causes of longevity and the impact on fitness parameters and gene expressions was analysed. The consideration of different ageing theories completed the analysis of the tannin action. All tannin-substances were able to prolong the lifespan but against all expectations, longevity and stress resistance were shown to be independent entities, which are not necessarily linked. Hormesis, CR-mimetic properties, antimicrobial capacities as well as several stress relevant genes are partly responsible for the life-extension. The antioxidant capacities, however, appeared to be irrelevant. The regulation of several hundred gene expressions by tannic acid underlined the complexity of the mode of action. Furthermore, the results partly confirm the “Disposable Soma Theory”, the “Mitohormesis Theory” and the “Green Theory of Ageing”. This work dissects the contrasting efficiency of the tannin family and underlines in particular, that tannins are molecular regulators, which should not be reduced to their antioxidative and antinutritional capacities

Cette étude présente une dimension économique, sociale et environnementale très importante. Elle rentre dans le cadre du projet Franco-Marocain PHC Toubkal (Ecopama, Volubilis 2012). Son objectif majeur est de valoriser les écorces Marocaine d’Acacia mollissima par une extraction verte permettant l’obtention des produits réactifs, des tanins condensés, qui seront utilisés dans le collage des panneaux de contreplaqués. Trois méthodes d’extraction ont été étudiées. Deux sont conventionnelles, une macération et une infusion ; ces deux techniques d’extraction sont simples, peu coûteuses. La troisième est une extraction assistée par micro-ondes ; c’est une technique innovante, rapide et peu consommatrice en solvant. La méthodologie des plans d’expériences est utilisée dans cette étude pour déterminer les facteurs les plus significatifs pour l’amélioration du rendement d’extraction des tanins condensés, optimiser les conditions d’extractions, réduire la proportion de solvant utilisé ainsi que le temps d’extraction. L’impact des conditions d’extraction et des méthodes d’extraction sur la teneur des tanins condensés sont étudiés pour la première fois pour les écorces d’Acacia mollissima du Maroc. Les extraits ont été caractérisés par des dosages colorimétriques, par des analyses structurales et thermiques. Les trois méthodes d’extraction ont été comparées. La teneur des extractibles est affectée par la proportion de solvant utilisé et le temps d’extraction. L’extraction assistée par micro-onde présente des teneurs en tanins condensés supérieure à l’extraction par des méthodes conventionnelles mais la teneur en sucre extraits est aussi élevée. Des formulations de colles à base de tanin et de lignosulfonate ont été élaborées en utilisant l’hexamine comme durcisseur. La colle biosourcée et ses constituants ont été caractérisés par analyse thermogravimétrique (ATG), et par calorimétrie différentielle à balayage (DSC). Les propriétés thermomécaniques et mécaniques des colles élaborées sont évaluées. L’optimisation des conditions de pressage des panneaux de contreplaqués, ainsi que le ratio tanin-lignosulfonate glyoxalé, ont été réalisées. La résistance des panneaux à l’eau froide et chaude est améliorée par l’addition de la résine époxy aux formulations de colle. Les propriétés mécaniques des panneaux de contreplaqués encollés ont été évalués par des tests normatifs et ont été comparés à celle des résines synthétiques commerciales (urée formaldéhyde et phénol formaldéhyde). La qualité de collage des panneaux élaborés a été évaluée. Les différentes colles présentent des caractéristiques physiques et thermiques satisfaisantes et acceptables pour les industries de collage des panneaux de bois. Des panneaux de contreplaqués avec de bonnes performances mécaniques et une excellente résistance à l’eau froide et bouillante ont été fabriqués. Ces colles présentent une qualité de collage qui se rapproche de celle des résines phénol-formaldéhyde, et peuvent être utilisées avec succès, pour une application industrielle des panneaux de contreplaqués, en milieu sec, humide et extérieur. / This study has an important economical, social and environmental dimension. It was conducted within the framework Franco-Moroccan PHC Toubkal "Ecopama, Volubilis 2012". The desire to enhance Moroccan bark of Acacia mollissima by the use of green extraction and also to obtain reagent products, condensed tannins, was the main objective of this study. These tannins will be used in the bonding of plywood panels. Three extraction methods were studied. Two are conventional, maceration and infusion; witch is simple and cheap extraction method. The third is microwave assisted extraction which is a fast, innovative method using a small amount of solvent. The experimental design methodology was used to identify the significant factors to improve yield extraction of condensed tannins, to optimize extraction process, to reduce solvent proportion and time extraction. The impact of extraction conditions and extraction process were studied for the first time on condensed tannins contents extracted from Moroccan bark of Acacia mollissima. The extracts were characterized using colorimetric assays, structural and thermal analysis.The three types of extraction were compared. The extractibles contents were affected by solvent proportion and also time extraction. Microwave assisted extraction produced a higher condensed tannins than the conventional method but in the other hand the sugars extracted is more important. Tannin-lignosulfonate adhesives were produced using hexamine as a hardener. The biobased adhesive formulations and their compounds were compared using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and by determining the thermal and mechanical proprieties of the adhesives. Optimal tannin-glyoxalated lignosulfonates ratio and pressing conditions of plywood panels were measured. The resistance of plywood panels to the cold and hot water was improved by the addition of epoxy resin in adhesive formulations. Mechanical properties of plywood panels made with tannin-lignosulfonates-epoxy adhesives were evaluated using normative standard and compared to those of panels made with a commercial resins (urea formaldehyde and phenol formaldehyde). The bonding quality of plywood panels elaborated was evaluated. The various adhesives elaborated have satisfactory and acceptable physical and thermal characteristics for bonding panels used in wood industries. Plywood panels with good mechanical performance, good resistance to cold water and to boiling water, were produced. The bonding quality of the adhesives elaborated in laboratory scale presented approximate proprieties than the phenol-formaldehyde resins which can use with successfully in dry, wet and exterior industrial application of plywood panels.

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