Tesi: "Tannin" – Grafiati

1

Garnier, Sandrine. "Rhéologie des tannins polyflavanoi͏̈des industriels et des adhésifs tannin-aldéhyde". Nancy 1, 2002. http://docnum.univ-lorraine.fr/public/SCD_T_2002_0028_GARNIER.pdf.

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Les modules dynamiques de solutions aqueuses d'extraits de tannins polyflavanoi͏̈des commerciaux : mimosa, pin, pécan et quebracho ont été mesurés par rhéométrie en fonction de l'amplitude de déformation et de la fréquence. La gélification et le durcissement des tannins avec le formaldéhyde ont été étudiés par rhéologie. De nouvelles méthodes de calcul ont permis de déterminer les propriétés rhéologiques de la polycondensation tannin-formaldéhyde : point de gel, énergie d'activation, degré de conversion, cinétique et d'analyser les effets de la température, la concentration en durcisseur et la nature du tannin. Les diagrammes TTT et CHT des adhésifs à base de tannins ont été construits pour différents pH et concentrations de formaldéhyde en suivant par analyse thermomécanique le durcissement de la résine in-situ un joint de colle. Des équations corrélant la force de cohésion interne des panneaux de particules à la déflexion minimale mesurée par TMA sur un joint de colle ont été établies
Commercial mimosa, quebracho, pine and pecan polyflavonoid tannin extracts water solutions of various concentrations were examined by rheometry, measuring dynamic moduli as a function of strain amplitude and frequency. Gelling and hardening reactions of tannin extracts with formaldehyde were studied by rheometry. Methods to determine rheological characteristics of tannin-formaldehyde polycondensation reactions before and after gel point were developed. Effect of temperature, influence of hardener concentration and tannin nature on gel point, activation energy, degree of conversion and kinetic were investigated. TTT and CHT curing diagrams of tannin-based adhesives were built for various pH and formaldehyde concentrations, using thermomechanical analysis to follow the hardening of the resin in-situ a wood joint. Regression equations relating the internal bond strength of a particleboard with the inverse of the minimum deflection measured by TMA during cure of a wood joint were obtained

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2

Auad, Priscila. "Composição química de taninos vegetais, curtimento e propriedades nos couros". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/185808.

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O Brasil é o país que possui o maior rebanho bovino comercial do mundo, e o balanço de exportações de couro vem demonstrando ascensão no número de metros quadrados de couros exportados. No processo produtivo, a etapa de curtimento é de extrema importância para transformar a pele bovina em couros, tornando-a resistente ao ataque de microorganismos, além de conferir enchimento e garantir maior estabilidade hidrotérmica do material. O crescente apelo ambiental pela utilização de materiais renováveis na indústria levou aos taninos vegetais desempenharem papéis importantes como compostos curtentes na indústria coureira. Os taninos são estruturas fenólicas complexas, existindo uma quantidade considerável de parâmetros químicos que podem ser mensurados através de diversas técnicas analíticas. Por outro lado, para os couros, também existem ensaios empregados no produto final, cujo desempenho pode depender do material curtente utilizado. No presente estudo, foram empregados cinco tipos de taninos de maior uso na indústria coureira para avaliação de parâmetros químicos e posterior associação com propriedades nos couros: tanino de acácia, quebracho, castanheiro, mirabolano e tara. Inicialmente, foi realizada uma revisão bibliográfica, a fim de determinar propriedades químicas de maior relevância a serem mensuradas nos taninos no contexto de sua utilização como agentes curtentes. Nesse sentido, elencaram-se os ensaios de determinação de tanantes totais, não-tanantes, sólidos insolúveis, sólidos solúveis, sólidos totais, fenóis totais e massa molecular média para os taninos. Os parâmetros de percentual de sólidos insolúveis, sólidos solúveis não-tanantes e tanantes totais distinguiram bem os grupos de taninos que atravessaram dos que não atravessaram o couro. Assim, pela análise de insolúveis ser a mais simples e direta delas, recomendar-se-ia o seu uso para definir uma faixa de corte para distinguir o desempenho dos taninos no curtimento. A análise de FTIR-UATR foi útil na caracterização e distinção dos taninos nas famílias dos hidrolisáveis e condensados. Os ensaios de temperatura de retração e distensão da flor nos couros também mostraram associação com o atravessamento dos taninos nas peles durante o curtimento. Por fim, a diferença total de cor após exposição à luz UV também foi avaliada para os couros curtidos com os taninos vegetais, sendo que os taninos hidrolisáveis apresentaram uma menor diferença de cor em relação aos condensados.
Brazil is the country with the largest commercial cattle herd in the world, and the balance of exports of leather has shown a rise in the number of square meters of exported leather. In the production process, the tanning step is extremely important to transform the skin into leather, making it resistant to the attack by microorganisms, as well as providing filling and assuring greater hydrothermal stability of the material. The increasing environmental approach for the use of renewable materials in the industry has led to vegetable tannins an important role as tanning compounds in the leather industry. Tannins are complex phenolic structures and there are a considerable amount of chemical parameters that can be measured through various analytical techniques to characterize them. On the other hand, for hides, there are also tests used in the final product, whose performance may depend on the tanning material used. In the present study, five types of tannins highly used in the tanning industry were used for the evaluation of their chemical parameters and later correlation with properties in hides: Black Wattle (Acacia mearnsii), Quebracho (Schinopsis lorentzii), Chestnut (Castanea sativa), Tara (Caesalpinia spinosa) and myrabolan (Terminalia chebula). Initially, a bibliographical review was carried out to determine the most relevant chemical properties to be measured in the tannins in the context of their use as tanning agents. In this context, the assays for the determination of total tannin polyphenols, non-tannin polyphenols, insoluble solids, soluble solids, total solids, total phenols and average molecular weight for tannins were performed. FTIR-UATR analysis was useful in characterizing and distinguishing tannins in their families of hydrolysates and condensates. The Mann-Whitney-U test showed that the insoluble solids, non-tannin polyphenols, soluble solids and total tannin polyphenols percentage distinguished well the groups of tannins that crossed the hide from those that didn´t. Hence, once the analysis of insoluble solids is the simplest and the most direct of them, it would be recommended to use this parameter to define a cutting range to distinguish the performance of tannins in leather tanning. The shrinkage temperature and distension tests in the leather also showed association with the leather cross-sectional results during tanning baths. Finally, the total color difference after exposure to UV light was also evaluated for the tanned hides with the vegetable tannins, and the hydrolysable tannins presented a smaller color difference or greater light fastness in comparison to the condensates.

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3

Wu, Jiacheng, Guoqiang Ning, Jinwei Zhang e Wuyong Chen. "Ti (III)-tannin combination tanning technology based on microwave irradiation - 76". Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34274.

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Content: Microwave is a fast, efficient and energy-saving thermal resource, hence an attempt has been made for applying this technology in the combination tanning using titanium (III) and tannin extracts. In this work, the microwave effects on the complex reaction of Ti (III) with tannin extracts and leather products properties were investigated. The precipitation condition was used to characterize the complexation degree between Ti (III) and tannin extracts. And the shrinkage temperature, tear strength, SEM, DSC, TG, FT-IR, and histological structure were used to characterize the changes in the physical and chemical properties of the combined tanned leather. Take-Away: The results showed that microwave irradiation can accelerate the complex reaction of Ti (III) with tannin extracts. At the room temperature, the mixture of tannin and titanous sulphate kept stable at pH 3-4. In addition, microwave could increase the shrinkage temperature, tear strength, thermal stability, and fibrage of Ti (III)-tannin tanned leather, and it would not change the combination mode of the skins with tanning agents as well as the hierarchical structure of collagen. Therefore, these results inferred that microwave could promote the reaction between Ti (III) and tannins and the combination of tannins with collagen, which may provide a theoretical basis for the application of microwave in Ti (III)-tannin combination tanning technology.

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4

Oliveira, Franciéli Borges de. "Utilização de matéria-prima obtida de fonte renovável na preparação de compósitos de matriz tipo fenólica". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-13102008-143432/.

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A matéria-prima utilizada na produção em larga escala de resinas fenólicas (normalmente fenol e formaldeído) é obtida a partir de fontes não renováveis. O tanino e o furfural, originados de fonte renováveis, apresentam a possibilidade de substituir parcialmente o fenol e formaldeído, respectivamente, na preparação de resinas fenólicas, formando uma rede integrada baseada em unidades de fenol/tanino e fenol/furfural para as resinas taninofenólica e fenol-furfural, respectivamente. No presente trabalho, estas resinas foram utilizadas na preparação de compósitos, os quais foram reforçados com fibras lignocelulósicas (sisal). As resinas taninofenólica e fenol-furfural foram caracterizadas por Ressonância Magnética Nuclear (RMN). Para análise da resina fenol-furfural, compostos modelo foram previamente sintetizados e avaliados por RMN 1H e 13C. Fibras de sisal foram usadas como agente de reforço das matrizes termorrígidas do tipo fenol, tendo em vista as excelentes propriedades mecânicas que esta fibra apresenta, assim como a disponibilidade da mesma no país, pois o Brasil é atualmente o maior produtor mundial desta fibra. Foram utilizadas fibras de sisal (3,0 cm de comprimento) em porcentagens diversas, sem tratamento e mercerizadas (tratamento com solução alcalina). Foram utilizadas também fibras tratadas com ar ionizado e reagidas com tanino hidroximetilado, variando-se o tempo de exposição das fibras ao tratamento. Os compósitos preparados com resina taninofenólica, contendo fibras de sisal tratadas (mercerização, ar ionizado e tanino hidroximetilado), apresentaram uma diminuição no valor de resistência ao impacto, quando comparados aos compósitos preparados com fibras de sisal sem tratamento. Provavelmente, estes tratamentos degradaram as fibras de sisal, tornando-as mais frágeis. As análises de microscopia eletrônica de varredura (MEV) destes compósitos reforçados com fibras tratadas, mostraram uma maior adesão entre fibra e matriz. Este aumento da adesão na região da interface foi confirmado pelos resultados obtidos nos testes de absorção de água, em que os compósitos contendo fibras de sisal mercerizadas absorveram no geral menores quantidades de água, confirmando que os tratamentos aplicados na fibra diminuíram o caráter hidrofílico característico das fibras de sisal sem tratamento. Os parâmetros obtidos a partir das curvas de absorção de água, revelaram que a difusão das moléculas de água no interior dos compósitos segue o regime fickiano. Para os compósitos de matriz fenol-furfural, a fim de avaliar os efeitos da natureza dos álcalis utilizados na propriedade destes compósitos, as resinas foram preparadas usando como catalisadores KOH e K2CO3, sendo na seqüência aplicadas na preparação de compósitos reforçados com fibras de sisal (3,0cm, 30% em massa, não tratadas). As análises de MEV mostram que a adesão na interface fibra/matriz é mais intensa quando KOH é utilizado, se comparado a K2CO3. Essa baixa adesão é provavelmente devido a possível liberação de CO2, quando K2CO3 é usado, que pode promover o surgimento de microcavidades em torno das fibras, o que pode levar a baixa adesão fibra/matriz. Essa baixa adesão se reflete na propriedade de resistência ao impacto, pois para os compósitos preparados com KOH os valores foram superiores. Ainda, para verificar se a resina obtida usando KOH pode ser preparada a partir de condições mais suaves, um experimento foi realizado com menores tempos de reação e temperatura. A resistência ao impacto deste compósito mostrou que um material com boas propriedades pode, ser obtido quando as resinas são preparadas nestas condições. Os resultados obtidos são promissores, e mostram que compósitos com boas propriedades podem ser preparados usando altas proporções de materiais obtidos de biomassa, isso é, fibras de sisal, tanino e furfural.
In the present work phenolic type matrices were prepered, which were reinforced with lignocellullosic fibers (sisal). The tannin-phenolic and phenol-furfural resins, amid other techniques, were characterized by nuclear magnetic resonance (NMR). Model compounds were synthesized specially for the 1H and 13C NMR analysis of phenol-furfural resins. The sisal fibers were chosen as reinforcing agent of the phenol-type thermoset matrices, due to their excellent mechanical properties, as well as the availability of this lignocellulosic material in Brazil, which is currently the greater world-wide producer of these fibers. Several percentages of unmodified and alkali treated (mercerized) fibers (3.0 cm length, randomly distributed) were used. Up to 50% of fibers (w/w), the impact strength of the composites improved with increase in the fiber content. In addition, fibers treated with ionized air and with hydroxymethylated tannin, varying the time exposure of the fibers to the treatments, were used. The tannin-phenolic matrices composites reinforced with 30 % (w/w) of modified sisal fibers (mercerized, treated with ionized air and hydroxymethylated tannin), showed lower impact strength than reinforced with sisal unmodified fibers. Probably, the sisal fibers were partially degraded by these treatments, turning them more fragile mechanically. The scanning electron microscopy (SEM) images of the composites reinforced with modified fibers showed better adhesion between fiber and matrix, confirmed by the results obtained from the water absorption experiments, where the composites reinforced with modified sisal fibers absorbed, in general, lesser amounts of water, indicating that the treatments applied in the fiber decreased the hydrophilic character of the fibers. The parameters obtained from the curves of water absorption revealed that the diffusion of water molecules within of the composites follows the Ficks law. Concerning the phenol-furfural resins, to evaluate the effect of the nature of the alkali used in the properties of the related composites, the resins were prepared using KOH and K2CO3 as catalysts, and then used in the preparation of composites reinforced with unmodified sisal fibers (3.0 cm length, 30% w/w, randomly distributed). The SEM images showed that the adhesion in the interface fiber/matrix was improved when KOH is used, instead of K2CO3. This low adhesion between fiber/matrix is probably caused by microcavities located around the fibers and possibly generated by CO2 release when K2CO3 is used in the preparation of the resin. This low adhesion reflects in the property of impact strength, for the composites prepared with KOH the values were superior. Nevertheless, to verify if the resin obtained using KOH can be prepared from softer conditions, a resin was prepared using lower reaction times (1h, instead of 3:15h) and temperature (70 °C, instead of 130 °C). The impact strength of the composite obtained from this resin showed that a material with good properties was obtained. Overall, the results are promising and indicate that composites with good properties can be prepared using high proportion of materials obtained from biomass, i.e., sisal fiber, tannin and furfural.

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5

Sanchez, Lucero Manuel. "Extraction of jojoba tannins and their role in protein-tannin complex formation and digestive proteases inhibition". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184405.

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Jojoba albumins and globulins were treated with jojoba tannins to study the protein-tannin complex formation. Trypsin and chymotrypsin were also treated with jojoba tannins to determine the change of enzymatic activity. The treated albumins and globulins were fractionated by gel filtration before and after treatment. Two albumin fractions did not appear after treatment, but a new fraction appeared with a shorter elution time. A precipitate was formed by addition of jojoba tannins to the jojoba globulins, and two globulin fractions did not appear after treatment. Trypsin was completely inhibited by 5.80 μg of tannin/ml. Chymotrypsin was completely inhibited by 36.44 μg of tannin/ml. Seven two-hour successive extractions with methanol were sufficient to obtain a jojoba meal which, when mixed at 15% in a ration with soybean, resulted in excellent growth of mice. Detannification of jojoba meal with methanol and acid methanol extracted other toxicants, because mice fed 15% of this jojoba meal gained more weight than the control. Acid methanol extraction was more effective than methanol or aqueous extraction in removing tannins; water extracted more protein and less tannin.

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6

Chen, Yumin. "Oxidation of Polymeric Polyphenols (Tannins) in Biologically Relevent Systems". Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1089232925.

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7

Navarrete, Fuentes Paola Jeannette. "Adhésifs naturels à base de tannin, tannin/lignine et lignine/gluten pour la fabrication de panneaux de bois". Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10089/document.

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Lors de cette étude, différentes recherches ont été effectuées sur l'utilisation de divers matériaux naturels comme source de matière premières pour la fabrication de colles vertes pour l'industrie de panneau. Dans ce contexte, le travail a consisté à : (i) Evaluer le potentiel de différents tannins en provenance de déchets d'écorces et développer des colles à base de tanins avec différents durcisseurs.(ii) Evaluer le potentiel de lignines de différentes origines et développer des colles à base de tannin de mimosa et de lignine. (iii) Développer des colles à base de tannin et de protéine de gluten.(iv) Evaluer les émissions de formaldéhyde et d'autres composés organiques volatiles (COV) à partir de panneaux de particules fabriqués avec les colles naturelles mises au point précédemment.Les techniques d'analyses thermomécaniques, de spectroscopie CP-MAS 13C NMR, de matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF) et de temps de gel ont été utilisées comme méthodes de travail pour l'évaluation et la caractérisation de ces colles. Les essais de cohésion interne pour l'évaluation de la résistance mécanique de la colle selon la norme EN -312 ont également été effectués.En ce qui concerne les émissions de formaldéhyde et des autres COV à partir de panneaux contentant des colles vertes, le recours à des techniques normalisées par chromatographie en phase gazeuse associée à un spectromètre de masse (GC-MS) et par chromatographie en phase liquide (HPLC) ont été privilégiées
This study deals with some researches carried out about the use of various natural materials as a source of raw material for the manufacturing of green adhesives for the industry of panel. In this context, work consisted in:(i) Evaluation of the potential of various tannins coming from barks wastes and development of adhesives containing tannins and various hardeners.(ii) Evaluation of the lignin potential from various origins and development of adhesives containing tannin from mimosa and lignin.(iii) Development of adhesives containing tannin and gluten protein.(iv) Evaluation of formaldehyde and other volatile organic compounds (VOC) from particleboards manufactures with the natural adhesives previously developed.Thermomechanical analyses, spectroscopy CP-MAS 13C NRM, matrix- assisted laser desorption/ionization mass spectroscometry (MALDI-TOF) and gelling time techniques were performed for evaluation and characterization of these adhesives. Internal bond test for the evaluation of adhesives mechanical resistance according to the standard EN-312 were also carried out.Concerning formaldehyde and other VOC emissions from panels with green adhesives, the recourse to standardized techniques which are gas chromatography associated with a mass spectrometer (GC-MS) and high performance liquid chromatography (HPLC) were privileged

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8

Navarrete, Fuentes Paola Jeannette. "Adhésifs naturels à base de tannin, tannin/lignine et lignine/gluten pour la fabrication de panneaux de bois". Electronic Thesis or Diss., Nancy 1, 2011. http://www.theses.fr/2011NAN10089.

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Lors de cette étude, différentes recherches ont été effectuées sur l'utilisation de divers matériaux naturels comme source de matière premières pour la fabrication de colles vertes pour l'industrie de panneau. Dans ce contexte, le travail a consisté à : (i) Evaluer le potentiel de différents tannins en provenance de déchets d'écorces et développer des colles à base de tanins avec différents durcisseurs.(ii) Evaluer le potentiel de lignines de différentes origines et développer des colles à base de tannin de mimosa et de lignine. (iii) Développer des colles à base de tannin et de protéine de gluten.(iv) Evaluer les émissions de formaldéhyde et d'autres composés organiques volatiles (COV) à partir de panneaux de particules fabriqués avec les colles naturelles mises au point précédemment.Les techniques d'analyses thermomécaniques, de spectroscopie CP-MAS 13C NMR, de matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF) et de temps de gel ont été utilisées comme méthodes de travail pour l'évaluation et la caractérisation de ces colles. Les essais de cohésion interne pour l'évaluation de la résistance mécanique de la colle selon la norme EN -312 ont également été effectués.En ce qui concerne les émissions de formaldéhyde et des autres COV à partir de panneaux contentant des colles vertes, le recours à des techniques normalisées par chromatographie en phase gazeuse associée à un spectromètre de masse (GC-MS) et par chromatographie en phase liquide (HPLC) ont été privilégiées
This study deals with some researches carried out about the use of various natural materials as a source of raw material for the manufacturing of green adhesives for the industry of panel. In this context, work consisted in:(i) Evaluation of the potential of various tannins coming from barks wastes and development of adhesives containing tannins and various hardeners.(ii) Evaluation of the lignin potential from various origins and development of adhesives containing tannin from mimosa and lignin.(iii) Development of adhesives containing tannin and gluten protein.(iv) Evaluation of formaldehyde and other volatile organic compounds (VOC) from particleboards manufactures with the natural adhesives previously developed.Thermomechanical analyses, spectroscopy CP-MAS 13C NRM, matrix- assisted laser desorption/ionization mass spectroscometry (MALDI-TOF) and gelling time techniques were performed for evaluation and characterization of these adhesives. Internal bond test for the evaluation of adhesives mechanical resistance according to the standard EN-312 were also carried out.Concerning formaldehyde and other VOC emissions from panels with green adhesives, the recourse to standardized techniques which are gas chromatography associated with a mass spectrometer (GC-MS) and high performance liquid chromatography (HPLC) were privileged

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9

Glyphis, John Paul. "Herbivory and tannin polyphenols in mediterranean ecosystems". Thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/23167.

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10

Albertz, Megan Lee. "Isolation and Characterization of Protein-Tannin Complexes". Miami University Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1209128363.

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11

Giovando, Samuele. "Modification et stabilisation de la réactivité de tanins traités chimiquement : applications à la préparation de résines adhésives et de mousses écosoutenables". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0227/document.

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L'objectif de ce travail de thèse a été de produire des matériaux expansés à partir de produits d'origine naturelle, en particulier à partir de tanins. Au moment où cette thèse a débuté, des études étaient publiées sur la possibilité d'élaborer ce type de matériaux avec des formulations qui comportaient du formaldéhyde. Cela allait à l'encontre du caractère naturel recherché puisqu'en fait, on utilisait des produits naturels et les faisait réagir avec un produit cancérogène. Il n'était donc pas possible de les présenter comme des matériaux « verts ». Aussi, nous avons voulu au cours de ce travail, élaborer des matériaux expansés uniquement à partir de produits naturels ou en découlant. Les tanins sont des substances naturelles chimiquement actives qui peuvent être utilisées afin de remplacer des produits homologues dérivés du pétrole comme le phénol par exemple qui présente des caractéristiques de réactivité chimique très similaires à celles des tanins condensés. Des formulations comportant des tanins condensés ont d'ailleurs déjà été étudiées pour élaborer des matériaux expansés. En considérant cela, ce travail de thèse s'est déroulé sous la forme de différents projets convergents vers un objectif commun: la production de mousses aux tanins plus naturelles et plus intéressantes pour l'industrie. Cinq projets ont ainsi été menés : 1. analyses de différents tanins, condensés, hydrolysables et synthétiques ; 2. production de mousses aux tanins sans utilisation de formaldéhyde ; 3. production de mousses aux tanins sans solvants ; 4. production de mousses aux tanins rigides ou élastiques ; 5. production de mousses aux tanins, sans acides, mais avec une catalyse alcaline
The aim of this thesis was to produce foamed materials from natural products, especially from tannins. At the time this thesis began, studies were published on the possibility of doing this type of materials with formaldehyde containing formulations. This was contrary to the desired natural character because in fact, were used natural products reacted with carcinogenic product. It was not possible to present them as "green" materials. During this thesis our aim was to develop expanded materials only from natural or bio-derived raw materials. Tannins are chemically active natural substances that can be used to replace homologous oil derivatives such as phenol which has characteristics of chemical reactivity very similar to those of condensed tannins. Formulations containing condensed tannins have already been studied to develop expanded materials. Considering this argument, this thesis takes place in the form of various projects converging towards a common goal: production of foams with more natural impact and interesting for tannins industry. Five projects have been completed: 1. analysis of various tannins, condensed, hydrolysable and synthetic ; 2. tannin foams production without the use of formaldehyde ; 3. tannin foams production without solvents ; 4. tannin foams production with rigid or elastic behavior ; 5. tannin foams production without acids, but with an alkaline catalysis

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12

Hart, Sawyer(Sawyer H. ). "Re-strengthening demineralized bone via tannin-iron crosslinking". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/124588.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages [30]-[31]).
As the world population continues to age, the social and economic impacts resulting from osteoporosis will continue to rise. New treatments for the disease are needed now more than ever. Using tannin iron complexes we show that thin film deposition of the complexes are not only possible but effective at strengthening demineralized bone. Furthermore we show that by taking advantage of newly discovered tris-complexes that are able to form between tannic acid and ferrous iron ion in solution, the strengthening ability of the film increases dramatically. Specifically, we show that tannin iron tris-complex coating results in a 1062% increase in the flexural modulus for fully hydrated and demineralized bone.
by Sawyer Hart.
S.B.
S.B. Massachusetts Institute of Technology, Department of Materials Science and Engineering

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13

Zerbib, Marie. "Etude de la glycosylation de flavanols dans le raisin et incidence dans les vins". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG051/document.

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Les flavan-3-ols appartiennent à la famille des polyphénols retrouvés dans diverses plantes et majoritairement dans le raisin. Ils jouent un rôle primordial dans les mécanismes de défense des plantes, influent sur les propriétés organoleptiques du vin et sont potentiellement bénéfiques au niveau de la santé humaine. La voie de biosynthèse des flavanols monomères est décrite dans la littérature. Cependant, les mécanismes de formation des proanthocyanidines (polymères) sont inconnus à ce jour. Des études ont montré que les flavanols glycosylés sont des intermédiaires potentiels dans la biosynthèse des PA et permettent le transport des unités de flavanols du cytoplasme vers la vacuole de la cellule, où a lieu la polymérisation. Un criblage global des flavanols glycosylés présents dans des raisins à trois stades de développement et dans des vins de différents cépages a été réalisé en analysant séparément les pellicules et les pépins de raisin par une méthode d’UPLC-DAD-ESI-MS. La teneur de ces composés dépend de paramètres de type variété du raisin, tissu biologique étudié et stade de maturité. La présence de dimères de flavanol glycosylés a été montrée pour la première fois dans le raisin. Grâce à l’hémisynthèse de la (+)-catéchine 4’-O--glucoside et 7-O--glucoside, certains monomères ont été caractérisés comme appartenant à la classe des -glucosides. Une étude quantitative a montré l’évolution des flavanols glycosylés au cours du développement de la baie de raisin (pépins et pellicules séparés) provenant de trois cépages différents. Les monomères et dimères d’ (épi) catéchine diglycosylés ont été découverts pour la première fois et uniquement dans les pépins. Une diminution en monomères d’ (épi) catéchine monoglycosylés a été observée dans la pellicule au cours de la maturation du raisin. Les dimères d’ (épi) catéchine monoglycosylés s’accumulent un peu après le stade de véraison et diminuent ensuite à maturité. Les monomères et dimères d’ (épi) catéchine diglycosylés s’accumulent dans les pépins au cours de la maturation. Finalement, l’évolution des teneurs en flavanols mono et diglycosylés au cours de microvinifications a été étudiée. On observe des profils d’extraction similaires pour les deux variétés utilisées (Grenache et Syrah). La quantité totale des différentes familles de composés augmente au cours de la vinification, et ensuite diminue en fin de FA. Certains composés sont dégradés préférentiellement, suggérant la présence d’activités glycosidases spécifiques du raisin ou de la levure
Flavan-3-ols belong to a group of polyphenols present in a wide variety of plants, and particularly in grapeberries. They play an important role in defense mechanisms in plants, have a significant impact on wine organoleptic properties; and their beneficial effects on human health may help to protect against chronic diseases such as atherosclerosis. The sequence of common flavanol monomer biosynthesis is widely described in the literature, but the formation mechanisms of proanthocyanidins (PA) remain unknown. Studies show that flavanol glycosides are potential intermediates in PA polymerization and have transporter roles of monomeric units from cytoplasm to vacuole in cell, where polymerization takes place. Global screening of grapeberry flavanol glycosides were carried out at three stages of grape development and in wines of different varieties; skin and seeds were measured separately using an UPLC-DAD-ESI-MS method. The composition of the target isomers depends on different parameters such as tissue type or stage of development. The presence epi catechin monoglycoside is reported here for the first time in grapes. Using (+)-catechin 4’-O--glucoside and 7-O--glucoside hemisynthesis, several monomers were shown to -glucosides. Quantitative analysis demonstrates the evolution of flavanol glycosides in both skin and seeds during the development of three grapevine varieties. For the first time monomeric and dimeric (epi) catechin diglycosides were revealed and shown accumulate only in grape seeds during ripening. A reduction in the concentration of monomeric (epi) catechin monoglycoside was observed during grape skin development. Dimeric (epi) catechin monoglycosides accumulate after veraison and then decrease at the end of grape ripening. The extraction profiles of flavanol glycosides during red grape fermentation showed similar evolution patterns for both varieties used. The total concentration of different compound families increases during winemaking, and then decreases at the end of fermentation. Degradation of specific compounds was observed at the end of fermentation which may be explained by the activity of glycosidases from grape extracts released during fermentation and pressing

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Gaeta, Henrique Hessel. "Avaliação de compostos polifenólicos nos efeitos induzidos pela sPLA2 de veneno cortálico e botrópico". Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153495.

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A explosão respiratória está fortemente associada ao processo inflamatório, uma vez que diversos compostos antioxidantes estão envolvidos na potencialização ou neutralização deste processo. Diversos peróxidos inorgânicos e orgânicos são produzidos durante esse processo, como os hidroperóxidos de lipídio. Hidroperóxidos de lipídio são estáveis, extremamente reativos e podem induzir a apoptose celular. Tais lipídios modificados podem ser produzidos durante o processo inflamatório induzido pelas fosfolipases A2 (PLA2) que constituem o veneno de serpentes, que possui como consequência de sua atividade catalítica a produção de ácido araquidônico pela quebra de fosfolipídios de membrana, e estes então seriam oxidados por espécies reativas de oxigênio (ROS), formando os hidroperóxidos araquidônicos, que agravam o quadro inflamatório. Deste modo, nesse trabalho avaliamos o efeito protetor de compostos polifenólicos e extratos ricos em tais compostos de diferentes espécies vegetais no curso da inflamação e miotoxidade e no efeito inflamatório pró-oxidante induzido pela PLA2 purificada de veneno crotálico e botrópico. Nossos resultados mostraram que diversos compostos polifenólicos são capazes de diminuir os efeitos provocados pela PLA2, interagindo diretamente, inibindo a enzima e possivelmente atuando na captura de ROS.
Respiratory burst is strongly associated with inflammatory process, since several antioxidant compounds are involved in potentiation or neutralization of this process. Various inorganic and organic peroxides are produced during this process such as lipid hydroperoxides. Lipid hydroperoxides are stable, highly reactive and can induce cellular apoptosis. Such modified lipids can be produced during the inflammatory process induced by phospholipases A2 (PLA2) which are present in snake venom, and produces, because of its catalytic activity, arachidonic acid by the breakdown of membrane phospholipids, and these would then be oxidized by reactive oxygen species (ROS), forming the arachidonic hydroperoxides, which aggravates inflammation. Thus, in this work we evaluated the protective effect of polyphenolic compounds and extracts rich in such compounds of different plant species throughout the inflammation and myotoxicity and in pro-oxidant effect induced by PLA2 purified from bothrops and crotalus venom. Our results showed that polyphenolic compounds can decrease effects caused by PLA2, by directly interaction, inhibiting the enzyme and possible acting to capture ROS.

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Li, Xinjun. "Mousses rigides et élastiques à base de tannins et d'albumine : préparation, caractérisation et modification". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0036/document.

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Du fait de leur faible coût, de leur bonne résistance à la compression, de leur fort pouvoir isolant et de leur résistance au feu, les mousses tannin/furanique constituent une alternative très intéressante aux mousses phénoliques et aux polyuréthanes dans diverses applications. Par ailleurs elles sont constituées à 95 % de matériaux naturels. Cependant, les mousses tannin/furanique sont : a) moins résistantes mécaniquement que les mousses synthétiques telles que phénoliques et polyuréthanes; b) potentiellement toxiques si le formaldéhyde utilisé pour les formuler est libéré dans l'environnement ; c) par ailleurs, des mousses légèrement élastiques seraient un plus. Dans cette thèse, des modifications et les caractérisations associées des mousses tannin/furaniques sont apportées pour résoudre ces défauts. Ce travail a été réalisé en quatre étapes principales :1) Étude et compréhension de la relation structure - propriétés des mousses. Dans ce but, les agents gonflants tels que le diéthyléther, le pentane, et des isocyanates et des polyuréthanes ont été particulièrement étudiés.2) Du noir de carbone, des nanotubes de carbone, de l'argile micronisé, des oligomères d'un polymère hyperramifié (ester-amine), des isocyanates et des polyuréthanes ont été ajoutés dans les formulations des mousses pour tenter d'améliorer leurs propriétés mécaniques et modifier leurs structures cellulaires.3) Le glutaraldéhyde et le glyoxal ont été essayés pour remplacer le formaldéhyde et préparer ainsi des mousses exemptes de formaldéhyde.4) Une nouvelle mousse, la mousse d'albumine, a été préparée, caractérisée et optimisée
The solid foams, because of their low density and cell structure, are commercial products with more and more interest. In recent decades, various methods for making foams based on bio-based materials have been prepared and characterized, such as lignin, starch and tannins. Because of their low cost, their resistance to compression, their high insulation and resistance to fire, tannin/furanic foams are supposed to be alternatives of phenolic foams and polyurethane in various applications. However, tannin/furanic foams are: a) lower mechanical resistant than synthetic foams such as polyurethane and phenolic foams b) potentially toxic because of formaldehyde, c) it is also interesting to prepare a foam more elastic. In this thesis, These works were carried out by four main steps: 1) Study and understanding the relationship of structure and properties of the foams. So different blowing agents, such as diethyl ether, pentane, and isocyanates and polyurethanes, were studied. 2) Carbon black, carbon nanotubes, nano clay, oligomers of hyperbranched poly (ester-amine) and pMDI were added to the formulations to improve their mechanical properties and change their cellular structures. 3) Glyoxal and glutaraldehyde have been tried to replace and prepare formaldehyde-free formaldehyde foams. 4) A new foam, albumin foam was prepared, characterized and optimized

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McKiearnan, Allison Nicole. "Effects of condensed tannin on in vitro ruminal fermentation". Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/18998.

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Master of Science
Department of Animal Sciences and Industry
KC Olson
Condensed tannins (CT) in plants are phenolic compounds with relatively high binding affinities for proteins. In ruminants, dietary CT limit DM intake and digestibility, and ruminal protein degradation by forming CT-protein complexes. Effects of dietary CT, animal species, prior dietary CT exposure, and antimicrobial inclusion on 48-h rate and extent of digestion were measured in two in vitro experiments. Cattle, sheep, and goats (n = 3 / species) were used in a 2-period, randomized complete-block experiment with a 2 × 3 × 2 × 3 factorial arrangement of treatments. Factor 1 was substrate: tannin-free or high-CT. Factor 2 was source of ruminal fluid inoculum: cattle, sheep, or goat. Factor 3 was prior animal exposure to a high-CT diet: non-exposed or exposed. Factor 4 was inclusion of antimicrobials: no antimicrobial, penicillin + streptomycin to suppress bacterial activity, or cycloheximide to suppress fungal activity in the fermentation. Tannin-free or high-CT substrates were incubated in vitro using ruminal fluid from animals either not exposed (period 1) or exposed to dietary CT (period 2). Periods consisted of an adaptation to tannin-free (10 d) or high-CT diets (21 d) and a 15-d period of ruminal-fluid collection via stomach tube. The presence of CT or penicillin + streptomycin in in vitro fermentation reduced (P < 0.001) total gas pressure, DM disappearance, and total VFA, acetate, propionate, butyrate, valerate, and branched-chain VFA concentrations. We concluded that: 1) CT had negative effects on fermentation, 2) prior exposure to dietary CT attenuated some but not all negative effects, and 3) CT effects were similar to the effects of penicillin + streptomycin.

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Hernes, Peter J. "Tannin geochemistry of natural systems : method development and application /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/11018.

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Castro, Gutiérrez Jimena. "Matériaux carbonés nanostructurés dérivés de tanin pour électrodes de supercondensateurs". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0126.

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Dans cette thèse, les propriétés physico-chimiques des carbones mésoporeux dérivés du tanin ont été étudiées et leurs performances électrochimiques en tant qu’électrodes pour des supercondensateurs (SC) ont été évaluées dans des électrolytes aqueux et organiques. L’objectif principal de cette étude était de développer une méthode de synthèse des carbones mésoporeux rapide, facile et respectueuse de l’environnement. Une nouvelle méthode de mésostructuration mécanochimique, assistée par l’interaction de l’eau avec un tensioactif, en une seule étape (SWAMM) a été développée et optimisée. Elle a permis de produire des carbones mésopororeux ordonnés et désordonnés (CMO et CMD, respectivement), uniquement en ajustant le rapport pondéral entre le tensioactif et l’eau. L’activation physique ou chimique des CMO et des CMD a permis d’améliorer les propriétés texturales des matériaux, ce qui a entraîné de bonnes performances des SC, même à des taux de charge élevés, dans des électrolytes aqueux et organiques. La caractérisation approfondie de ces nouveaux matériaux a également permis de mieux comprendre l’effet de l’ordre et de la connectivité de la structure micro-mésoporeuse sur le développement des propriétés texturales par les différents processus d’activation et, par conséquent, sur les performances électrochimiques des SC assemblés
In this thesis, the physicochemical properties of tannin-derived mesoporous carbons were studied and their electrochemical performance as electrodes for supercapacitors (SCs) was evaluated in aqueous and organic electrolytes. The main objective of this study was to develop a fast and easy, and environmentally friendly method for the synthesis of mesoporous carbons. A novel surfactant-water-assisted mechanochemical mesostructuration (SWAMM) one-pot method was developed and optimized to produce ordered and disordered mesoporous carbons (OMCs and DMCs, respectively), only by adjusting the surfactant to water weight ratio. Further physical or chemical activation of both OMCs and DMCs improved the textural properties of the materials that resulted in good SC performance, even at high charging rates, in aqueous and organic electrolytes. The in-depth characterization performed for these new materials has also led to a better understanding of the effect of order and connectivity of the micro-mesoporous structure on the development of textural properties by the different activation processes and, consequently, on the electrochemical performance of the assembled SC

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Kraiwattanawong, Kriangsak. "Synthesis of mesoporous carbon cryogels from wattle tannin and furfural". 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/136257.

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Garcia, Bruno Pienis. "Associação de taninos e silano na passivação de aço galvanizado". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/165150.

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A proteção contra a corrosão do aço galvanizado com um tratamento via cromatização, apesar de apresentar desempenho superior à outras alternativas, gera efluentes tóxicos ao meio ambiente e em especial aos seres humanos. Dentre as alternativas apresentadas até o presente momento, que incluem diversos tipos de tratamentos para esse substrato, um deles é o revestimento com silanos. Apesar desse revestimento ter um satisfatório desempenho, vem se utilizando incorporações em seu preparo, para se potencializar seu desempenho. A incorporação escolhida nesse trabalho foi a do tanino, um inibidor de corrosão natural, extraído de vegetais. O objetivo desse trabalho é avaliar um revestimento do silano Ortossilicato de tetraetila (TEOS) junto de um tanino para o aço galvanizado destinado a aplicações onde não há pintura. Essa sinergia deve proteger a superfície até que o zinco consiga de forma natural desenvolver sua pátina protetora, formando uma barreira entre substrato e eletrólito. Foram revestidas chapas de aço galvanizado com períodos de imersão que variaram entre 2 e 10 minutos, com soluções na concentração de tanino de 2g/L e 10g/L com diferentes valores de pH, em uma solução previamente preparada de TEOS em concentração de 2%, água 49% e etanol 49%. Realizou-se análise comparativa entre os diferentes parâmetros de tratamento proposto neste trabalho com aço galvanizado somente desengraxado e aço galvanizado cromatizado nas seguintes técnicas: espectroscopia de impedância eletroquímica, polarização potenciodinâmica, microscopia eletrônica de varredura acoplada a espectroscopia de energia dispersiva, e ensaios de corrosão acelerada em câmara úmida e névoa salina. Os resultados apresentados indicam que diferentes concentrações de tanino e tempos de imersão não são significativos para causar diferenças relevantes entre os desempenhos e que os substratos tratados demonstraram um desempenho superior comparado às amostras que não tinham nenhum tipo de tratamento e inferiores às amostras cromatizadas.
The corrosion protection of galvanized steel with a chromatized treatment, despite superior performance to other alternatives, generates effluents toxic to the environment and especially to humans. Among the alternatives presented to date, which include several types of treatments for this substrate, one of them is the coating with silanes. Although this coating has a satisfactory performance, it has been using incorporations in its preparation, to enhance its performance. The incorporation chosen in this work was that of tannin, a natural corrosion inhibitor, extracted from plants. The objective of this work is to evaluate a coating of silane tetraethyl orthosilicate (TEOS) with tannin for galvanized steel, for applications where there is no paint. This synergy should protect the surface until zinc can naturally develop its protective patina, forming a barrier between substrate and electrolyte. Galvanized steel plates were coated with immersion times ranging from 2 to 10 minutes, with solutions at tannin concentration of 2 g/L and 10 g/L with different pH values, in a previously prepared solution of TEOS at a concentration of 2% , 49% of water and 49% of ethanol. A comparative analysis was performed between the different treatment parameters proposed in this work with galvanized steel only degreased and galvanized steel chromatized in the following techniques: electrochemical impedance spectroscopy (EIE), potentiodynamic polarization, scanning electron microscopy coupled to dispersive energy spectroscopy, and corrosion tests accelerated in humid chamber and saline mist. The results indicated that different concentrations of tannin and immersion times are not significant to cause relevant differences between the performances and that the substrates demonstrated superior performance compared to the samples that had no type of treatment, and inferior to the samples chromatized.

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Delgado, Sánchez Clara. "Nouvelles méthodes d’optimisation et de caractérisation de mousses à base de tanins pour l’isolation thermique du bâtiment". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0246/document.

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Dans cette thèse, des mousses produites à plus de 90% à partir de produits naturels et à très faible conductivité thermique ont été étudiées en détail. L’objectif principal de ce travail était d’améliorer certaines faiblesses de ces matériaux et de résoudre les problèmes qui pourraient être rencontrés lors de leur utilisation, pour leur permettre de concurrencer d’autres mousses synthétiques actuellement sur le marché de l’isolation thermique. De nouvelles méthodologies ont été proposées pour optimiser les mousses à base de tanin de différents points de vue. Tout d’abord, des mousses liquides ont été analysées en termes de stabilité et de processus de polymérisation à l’aide d’un analyseur de lumière rétrodiffusée, afin de les transformer en mousses rigides de tanin plus performantes. Des plans d’expériences ont également été utilisés pour améliorer les propriétés mécaniques de mousses rigides, produites par moussage physique, sans porter préjudice à leur conductivité thermique. D’autre part, des traitements d’hydrophobisation ont été réalisés pour réduire la sensibilité de ces mousses à l’eau, qu’elle soit sous forme liquide ou vapeur, et l’effet des ingrédients des formulations sur leurs propriétés au feu a été élucidé. Enfin, deux techniques de caractérisation mécanique ont été étudiées et comparées, ce qui a permis de déterminer le coefficient de Poisson et le facteur de perte, et de mettre en évidence les précautions à prendre pour caractériser les mousses fragiles
In this thesis, foams based on more than 90% of natural products and with an exceptionally low thermal conductivity have been studied in depth. The main objective of this work was to improve some of the weaknesses of those materials and to solve problems that might be encountered during use, for allowing them to compete with other synthetic foams that are currently on the thermal insulation market. New methodologies have been proposed to optimise tannin-based foams from different points of view. First, liquid foams were analysed in terms of stability and polymerisation process using a backscattered light analyser, in order to convert them into improved rigid tannin-based foams. Experimental design was also used to improve the mechanical properties of physically blown rigid foams without prejudicing their thermal conductivity. On the other hand, hydrophobisation treatments were suggested for reducing the sensitivity of those foams to water in liquid or vapour form, and the effect of formulations’ ingredients on their fire properties were elucidated. Finally, two techniques of mechanical characterisation were investigated and compared, leading to Poisson’s coefficient and loss factor, and evidencing the precautions to be taken for characterising brittle foams

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Binti, Abdullah Ummi Hani. "Développement de stratifiés de papiers imprégnés à base de résine de tannin de mimosa et d'alcool furfurylique". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0060/document.

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Les papiers imprégnés de résine ont été largement utilisés dans la fabrication de stratifiés pour des panneaux de bois. Généralement, l'imprégnation du papier implique l’utilisation de resins mélamine-formaldéhyde, urée-formaldéhyde et melamine-formaldéhyde-urée. Cependant, ces matériaux sont coûteux lorsqu'ils sont utilisés en grande quantité et ils proviennent de ressources non renouvelables. Par conséquent, dans ce travail, nous avons préparé des papiers imprégnés de résines tannins furanique pour remplacer les résines mélamine-formaldéhyde et d'urée-formaldéhyde lors de l'imprégnation des papiers. Les résines tannins furaniques sont composées de deux matières naturelles principales: a) le tannin de mimosa qui est non-toxique, respectueux de l'environnement et relativement peu coûteux qui remplace la résine synthétique et b) de l'alcool furfurylique obtenu par réduction catalytique du furfural, un composé naturel obtenu par l'hydrolyse des sucres dérivés des déchets agricoles. Les tannins sont des composés phénoliques naturels extraits des écorces des arbres et qui ont été utilisés dans l'industrie depuis de nombreuses années comme adhésifs pour la production de panneaux de bois. Mais il n’y a pas jamais eu jusqu’à présent des recherches sur leurs utilisations dans la fabrication des stratifiés. Dans ce travail, nous avons étudié : 1) Le temps de gel entre des tannins de mimosa et des tannins de pin avec de l'alcool furfurylique, sans ajout de formaldéhyde de pH 1 à pH 11 2) L’analyse MALDI-TOF et RMN des tannins de mimosa avec de l'alcool furfurylique 3) La qualité de la surface du contreplaqué recouvert d’un papier imprégné de résine tannins de mimosa-alcool furfurylique 4) Les stratifiés de 10 plis à haute pression (HPL) ont été préparés avec de la résine tannins de mimosa-alcool furfurylique. La qualité de surface des HPL et les propriétés mécaniques du contreplaqué recouvert avec ces HPL ont été examinées. 5) Les stratifiés de 10 plis à haute pression ont été préparés avec de la résine de tannins de mimosa - alcool furfurylique en milieu acide. Les qualités de surface des HPL ont été comparées avec celles des HPL preparés avec une résine phénol-formaldéhyde
Resin impregnated papers have been widely used in manufacturing laminates for wood panels. Generally, paper impregnation involves melamine formaldehyde, melamine urea formaldehyde and urea formaldehyde resin. However, these materials are expensive when used in high quantity and derived from non renewable resources. Therefore, in this work we prepared tannin furanic resin impregnated paper to replace melamine formaldehyde and urea formaldehyde in the paper impregnation. Tannin furanic resin composed of two main natural materials: a) mimosa tannins which is non-toxic, environmentally friendly and relatively inexpensive to substitute the synthetic resin and b) furfuryl alcohol obtained by catalytic reduction of furfural, a natural compound obtained by the hydrolysis of sugars derived from agricultural waste. Tannins are naturally occurring phenolic compounds extracted from the bark trees that have been used industrially for many years as wood panel adhesives but no distance work have been done to study their potential in paper laminates. In this work, we studied: 1) The gel time between mimosa and pine tannin with furfuryl alcohol without the addition of formaldehyde from pH 1 to pH 11 2) The MALDI-TOF and NMR of mimosa tannin with furfuryl alcohol 3) The surface quality of the plywood overlaid with mimosa tannin- furfuryl alcohol resin 4) 10-ply high pressure laminates (HPL) were prepared with mimosa tannin- furfuryl alcohol resin. The surface quality of the HPL and the mechanical properties of plywood overlaid with this HPL were examined. 5) 10-ply high pressure laminates were prepared with mimosa tannin- furfuryl alcohol resin in the acid condition. The surface quality of the prepared HPL were compared with PF

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Kantar, Faik. "Studies on the establishment of white flowered (zero tannin) Vicia faba". Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304054.

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24

Keulder, Daniel B. "The influence of commercial tannin additions on wine composition and quality". Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/2482.

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Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2006.
The quality of wine is influenced by numerous factors of which the grapes, winemaking techniques and effective quality control are to name a few. The use of new techniques should be cost effective and always have a positive influence on the wine quality. The addition of commercial tannins to wine is a fairly new technique and the effects of these additions at the concentrations prescribed have not been investigated in detail. The commercial tannins can be added to wine for different reasons, which may include: stabilisation of colour, increasing the aging potential, to modify aromas, promote precipitation of proteins, limit the effect of laccase activity, substrate for micro-oxygenation, to act as a redox buffer and structural and mouth feel modification. The reason for the addition determines the type of commercial tannin that is used, the timing of the addition and the dosage used.

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25

Zhao, Zhongyuan. "Investigation of natural adhesive composed of tannin and sucrose for particleboard". Kyoto University, 2016. http://hdl.handle.net/2433/215602.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第19776号
農博第2172号
新制||農||1041(附属図書館)
学位論文||H28||N4992(農学部図書室)
32812
京都大学大学院農学研究科森林科学専攻
(主査)教授金山公三, 教授矢野浩之, 教授五十田博
学位規則第4条第1項該当

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26

Klug, Tammila Venzke. "Uso de extratos de taninos como sanitizantes em alface minimamente processada". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/183447.

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A sanitização com hipoclorito de sódio é recomendada para espécies hortícolas, porém há uma preocupação sobre uma possível formação a partir deste sanitizante de trihalometanos e ácidos haloacéticos, reconhecidos como compostos cancerígenos. Com base nisto, o objetivo do presente trabalho foi estudar o efeito microbiológico e qualitativo de sanitizantes à base de extratos de taninos de Acacia mearnsii como uso alternativo ao hipoclorito de sódio em alface minimamente processada. Foram conduzidos dois experimentos. No primeiro trabalho definiram-se as concentrações mínimas inibitórias (CMI) dos extratos de taninos SM®, SG® e AQ® contra a bactéria Escherichia coli ATCC 25972. Além disso, foram feitas avaliações da redução de células de E. coli na superfície de folhas de alface após 2h e 24h de incubação, após o uso de extratos de taninos: SM® 1%, SG® 1% e AQ® 2% por 10 min, solução de hipoclorito de sódio (200 mg/L) por 15 min e água potável por 1 min. A visualização da presença de bactérias na superfície das folhas após os tratamentos de sanitização foi realizada por meio de microscopia eletrônica de varredura (mev). No segundo experimento, alface minimamente processada foi sanitizada com os extratos de taninos SM® 1% (10 min), SG® 1% (10 min), solução de hipoclorito de sódio (200 mg/L / 15 min) e água potável (1 min) e armazenada a 3 ± 1ºC por 9 dias. Foram realizadas análises microbiológicas e físico-químicas, no dia da instalação do experimento (antes e após sanitização) e aos 5, 7 ou 9 dias. No primeiro experimento, as CMIs dos extratos de taninos SM® e SG® foram de 1% para E. coli, enquanto para o AQ® foi de 2%. Em relação à inoculação de E. coli na superfície de alface, os extratos SM® 1% e SG® 1% reduziram significativamente o número de células, comparável à eficácia de redução do hipoclorito de sódio, enquanto o extrato AQ® apresentou um menor efeito de redução não diferindo da redução obtida pelo uso de água. Após incubação de 24h observou-se formação de agregados celulares e foi possível visualizar células de E. coli no interior dos estômatos da folha de alface por mev. Os tratamentos SM® e SG® foram menos eficazes na redução de células de E. coli após incubação por 24h na comparação com a incubação por 2h, o que sugere que a internalização de bactérias no interior dos tecidos vegetais limitou a ação dos extratos de taninos. No segundo experimento, os melhores resultados microbiológicos e físico-químicos foram obtidos com o extrato tânico SM®, o qual não diferiu estatisticamente da solução de cloro. Os extratos de taninos reduziram significativamente a contagem microbiológica inicial das amostras de alface. Portanto, sugere-se o uso do extrato de tanino SM® na água de lavagem, com o objetivo de redução inicial da contagem microbiológica da alface.
Although sanitization with sodium hypochlorite is recommended for fresh cut vegetables, skepticisms remain concerning the possible formation of trihalomethanes and haloacetic acids, acknowledged carcinogenic compounds. Based on that, the present work intended to evaluate the microbiological and qualitative effects of sanitizers based on tannin extracts of Acacia mearnsii as an alternative to the use of sodium hypochlorite on fresh cut lettuce. Two experiments were conducted. In the first experiment, the minimal inhibitory concentrations (MIC) of the tannin extracts SM®, SG® and AQ® were defined against the Escherichia coli ATCC 25972. Furthermore, after a 2h or a 24h incubation period, the reduction of E. coli cells on the surface of lettuce leaves after the application of tannin extracts: SM® 1%, SG® 1% and AQ® 2% for 10 min, of solution of sodium hypochlorite (200 mg/L) for 15 min or water for 1 min was determined. Scanning electron microscopy (SEM) was performed after the sanitizing treatments. In the second experiment, fresh cut lettuce was sanitized with the tannin extracts SM® 1% (10 min) and SG® 1% (10 min), solution of sodium hypochlorite (200 mg/L / 15 min) and potable water (1 min) and stored at 3+1ºC for 9 days. Microbiological and quality analyses were completed at day zero (before and after sanitization) and after 5, 7 or 9 days of cold storage. On the first experiment, the MIC of the SM® and SG® tannin extracts was 1% for E. coli, while the MIC of the AQ® was 2%. Regarding the inoculation of E. coli cells on the lettuce leaves surface, the SM® (1%) and SG® (1%) tannin extracts significantly reduced the number of cells comparable to the reducing efficacy of sodium hypochlorite. The AQ® extract presented the lowest reduction, which was not statistically different from the reduction obtained by using tap water. After the 24h incubation period, a formation of cellular aggregates was observed facilitating the visualization of E. coli cells in stomata of lettuce leaves by means of SEM. Moreover, the SM® and SG® treatments were less efficient in the reduction of E. coli cells after the 24h incubation compared with the 2h incubation, which suggests that the internalization of bacteria in the interior of plant tissues limited the action of the tannin extracts. On the second experiment, the results were obtained with the SM® tannin extract, not showing statistical difference from the chlorite solution. The tannin extracts significantly reduced the initial microbiological count of the lettuce samples. Therefore, the use of the tannin extract SM® is suggested for rinsing water, with the objective of an initial reduction of the microbiological count on lettuce leaves.

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Teng, Xu, Zhang Wen-hua e Shi Bi. "Characteristics of typical pollutants in tannery site soil - 75". Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34271.

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Content: This paper briefly introduced the process of leather manufacture and the potential pollution sources of soil in tannery sites. Pollutants are mainly derived from the use of a large number of various chemicals and organic matter decomposed by raw skin. The characteristics of typical pollutants in tannery sites soil were summarized, including tannery site soil pH, organic and inorganic compounds, and heavy metals, etc., especially the status of chromium contamination were reviewed. The pH of soil in the tanning workshop (6.65-7.8) is generally lower than tannery sludge dumping site (7.94-8.40). The main organic pollutants contained in the tannery site soil include nitrogen compound, grease, petroleum hydrocarbon. In tannery sludge dumping site soil, the content of nitrogen compound (10cm depth) is 28400 mg/kg, which is similar to tannery sludge. The content of petroleum hydrocarbon is 5-700 mg/kg, which partially exceed the limits of China agricultural land quality standard(<500 mg/kg). In tanning workshop soil, the content of grease is 220-62000 mg/kg. The main inorganic pollutants contained in the tannery site soil include sulfide, high concentration of salt, lime. The high salt content of tannery sludge (99000 mg/kg) leads to high salt content in soil (5500-17500 mg/kg). Total hardness (>450mg/L), total dissolved solids (>1000mg/L), sulfate ions (>250mg/L), nitrite nitrogen (>0.02mg/L) partially exceed the limits of China groundwater quality standard, which are found in groundwater below the tannery site. Heavy metal pollutants in the tannery sites soil have many characteristics and large differences in content, due to the different tanning processes. Among them, chromium (Cr) is the most used heavy metal and the highest content of pollutants. Cr content in tanning process wastewater, dyeing process wastewater and chromiumcontaining sludge are about 2000-3000 mg/L, 30-40 mg/L and 8500-25800 mg/kg, respectively. Total Cr content in the partial tannery sites soil are higher than 800 mg/kg, which exceed the limits of China agricultural land quality standard(<150mg/kg). Surprisingly, Cr(VI) appears in tannery sites soil and the contents are partly higher than 40 mg/kg, which exceed the limits of China development land quality standard(<3.0mg/kg). Furthermore, the more effort needs to be directed toward the chemistry of chromium-organic complex pollutants, and an understanding of the speciation of Cr in highly organics contaminated tannery site soil is essential for the development of suitable remediation strategies for contaminated soil. Take-Away: 1. The pH of soil in the tanning workshop (6.65-7.8) is generally lower than tannery sludge dumping site(7.94-8.40). 2. Total Cr content in the partial tannery sites soil are higher than 800 mg/kg, which exceed the limits of China agricultural land quality standard(<150mg/kg). 3. Cr(VI) appears in tannery sites soil and the contents are partly higher than 40 mg/kg, which exceed the limits of China development land quality standard(<3.0mg/kg).

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28

Gaudin, Elodie. "Le sainfoin déshydraté - un modèle de nutricament dans la lutte contre les nématodes parasites des petits ruminants". Thesis, Toulouse, INPT, 2017. http://www.theses.fr/2017INPT0042.

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Les nématodes gastro-intestinaux (NGIs) sont une contrainte majeure en élevage des ruminants au pâturage. La méthode de lutte usuelle est l’utilisation de traitements anthelminthiques (AH) de synthèse. Cependant, la diffusion constante de résistances aux AHs dans les populations de NGIs chez les petits ruminants impose de rechercher des méthodes alternatives de maitrise. L’exploitation de plantes contenant des métabolites secondaires est une de ces options. Le sainfoin (Onobrychis viciifolia), une légumineuse riche en tanins condensés (TCs), est un modèle pour explorer le concept de nutricament = fourrage associant valeurs nutritionnelles et propriétés sanitaires (AH). Récemment, une filière de production de granulés déshydratés de sainfoin (GDS) s’est construite. Les avantages en sont : cultiver le sainfoin dans les meilleures conditions agronomiques possibles, favoriser la standardisation et la caractérisation des lots avant usage pour assurer leur distribution en élevages voire leur exportation. L’objectif général de cette thèse a été de fournir les informations scientifiques pour favoriser l’utilisation de GDS en élevage de petits ruminants. Il s’est décliné en 3 axes de recherche : Le premier axe visait à valider des méthodes simples de dosage des tanins et de leur activité biologique, pour caractériser des ressources avant usage, en se fondant sur des mesures biochimiques (méthode colorimétrique de Folin- Ciocalteu) et d’activité biologiques (complexation des protéines = méthode de diffusion radiale et activité AH = méthode du dégainement larvaire imitant le processus d’infestation in vivo). Les corrélations entre les diverses mesures montrent un lien entre la quantité de TCs et l’activité AH ainsi que l’intérêt de la méthode NIRS pour caractériser les différentes sources de sainfoin (GDS et fourrages). Le second axe visait à mieux définir sur la base d’études en conditions expérimentales contrôlées, les conditions optimales d’application des GDS en élevage. Une première série d’études a cherché à explorer 1) les effets AH combinés, liés à la concentration en TCs dans la ration et à la durée de distribution, contre divers stades (L3, vers adultes) d’espèces abomasales ou intestinales et 2) l’intérêt d’associer le sainfoin avec un AH de synthèse. Les résultats montrent 1) qu’un seuil minimum de TCs dans la ration doit être atteint et une période minimum de 15 jours de distribution est nécessaire pour altérer la biologie des nématodes (notamment la fertilité des vers femelles de Trichostrongylus colubriformis et le nombre d’Haemonchus contortus) et 2) qu’une utilisation dissociée d’un AH de synthèse (ivermectine par voie orale) est préférable en raison d’interactions négatives. Le dernier axe a visé à comparer la capacité d’ovins ou de caprins à moduler leur comportement alimentaire vis-à-vis de GDS en fonction de leur état parasitaire (capacité d'automédication). L’objectif était de vérifier les hypothèses suivantes : compte-tenu de leur moindre résistance envers les parasites et une plus grande propension à consommer des tanins, les caprins consommeront plus de sainfoin que les ovins ; les animaux fortement parasités exprimeront une préférence pour le sainfoin, et celle-ci augmentera au cours du temps. Les résultats de cet essai ont montré, dans le test de cafétéria, que 1) les chèvres préféraient le sainfoin et 2) une augmentation de la consommation en sainfoin au cours du temps chez les animaux parasités, sans toutefois devenir supérieure à celle des animaux sains. En revanche, ni les animaux parasités, ni les caprins n’ont montré de motivation plus importante pour obtenir la ressource riche en tanins dans le test de conditionnement opérant. Ces résultats montrent l’intérêt de l’utilisation de granulés de sainfoin en élevage, afin de compléter les AHs de synthèse et limiter le développement des résistances à ces molécules chez les NGIs
Gastrointestinal nematodes (GINs) represent a major threat for grazing ruminants. The traditional mode of control of these parasites mainly relied on the use of synthetic anthelmintics (AHs). However, the repeated use of these molecules has led to resistance against all AH drugs in worm populations of small ruminants. Alternative solutions are needed. Among those, the use of plants that contain plant secondary metabolites, such as condensed tannins (CTs), has been studied for the last 20 years. These CT-containing resources, such as sainfoin (Onobrychis viciifolia) have AH properties and beneficial effects on health and also interesting nutritional values; hence they correspond to the definition of nutraceuticals. Recently, an organization has developed to produce dehydrated pellets of sainfoin. The advantages of such pellets are 1/ to grow sainfoin in the best agronomic conditions; 2/ to better standardize the product; 3/ to evaluate the pellet before use and to facilitate exportation. The general aim of this thesis was to optimize the use of sainfoin pellets in farm conditions. Our first objective was to characterize the CT content and AH properties of sainfoin pellets. For industrial purposes, simple, low cost and repeatable methods to evaluate the CT content and the AH activity are requested in order to rapidly qualify the pellets. The CT content was evaluated by biochemical measurements of total phenols and tannins (Folin-Ciocalteu). This was completed by the measure of the complexation of tannins with proteins (Radial Diffusion) and by development of prediction calibrations using near infra-red spectroscopy (NIRS). The AH evaluation was performed on samples before and after dehydration, using the Larval Exsheathment Inhibition Assay. Calculations of correlations between the different methods showed significant links between the quantity of CT and the AH activity, and the possible use of NIRS to measure the CT content and the AH activity of pellets and forages. The second objective aimed at defining the optimal conditions to use sainfoin pellets on farm, to improve the AH activity. We aimed at analyzing, in experimental conditions, 1) how the combination of 2 factors, namely the CT concentration in feed and the length of distribution, influence the AH efficacy of sainfoin pellets on intestinal and abomasal L3 larvae or adult worms; 2) whether or not the combined use of sainfoin with a chemical AH (oral ivermectine) is beneficial. Results showed that a minimum CT content in sainfoin and a minimum length of distribution of 15 days are mandatory to alter the adult worm and L3 larvae biology of nematodes, particularly the Trichostrongylus colubriformis fertility and the number of Haemonchus contortus. Moreover, the combined use of AH and sainfoin consumption should be avoided because of negative interactions. The last axis aimed at studying the behavior of sheep and goats in relation to sainfoin pellets and their ability to change the feeding behavior according to their parasitic status (self-medication ability). The objective was to verify the following hypotheses: due to their lower resistance against parasites and their higher propensity to eat CTs, goats will eat more sainfoin than sheep, parasitized animals will prefer sainfoin and this preference will increase overtime. The results showed that two of our hypothesis were verified in a cafeteria study: 1) goats preferred sainfoin while sheep preferred alfalfa and 2) the sainfoin consumption increased overtime for infected animals, without being higher than nonparasitized ones. However, nor goat, nor parasitized animals, showed a higher motivation in the operant-conditioning trial to feed on CT rich resources. All the present results showed the interest to exploit sainfoin pellets in farms, as one alternative to AHs molecules in order to limit the development of resistances to these drugs in GIN populations

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29

Mole, Simon. "Tannins : a biochemical re-analysis of their importance as anti-feedants". Thesis, University of Strathclyde, 1986. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21472.

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Tannins have long been thought of as antifeedants owing to their presumed digestibility-reducing properties. In this thesis information, at the molecular level, is presented in a reassessment of this assumption and the apparency theory of plant chemical defence which is dependent upon it. An introductory review provides chemical and opperational descriptions of tannins and a general outline of their ecological impact. Detailed attention is given to (i) tannin-protein complex formation and (ii), an assesment of in vivo evidence concerning the effects of tannins on herbivores. It is concluded that the evidence does not support the hypothesis that tannins uniformly reduce digestion, even though they do generally act as antifeedants. A series of crude tannin-containing plant extracts were prepared and characterised by chemical analyses and by their ability to precipitate protein and inhibit pepsin/cellulase digestion of celulose. Results indicated between-tannin variation but not that the chemical properties of crude tannins might be used to predict their interaction with the other components of a herbivore's diet. Experiments under conditions where soluble tannin-protein complexes formed and which modelled some digestive systems, showed that tannins could under varying circumstances, inhibit or promote the digestion of protein. Soluble tannin-protein complexes were also formed in the presence of bile salts when they would otherwise have occured as precipitates. In these conditions clear relief from digestibility reduction was found. In the light of these results a new model describing the effects of tannins on digestion, consistent with results obtained in vivo, is proposed.

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30

Omolayo, O. O. "The effect of endogenous tannins on the suitability of sorghum grains for brewing". Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355505.

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31

Khan, Muhammad Younas. "Synthesis and characterization of superparamagnetic nanoparticles containing Fe3O4 core in pyrolyzed tannin". reponame:Repositório Institucional da UFPR, 2015. http://hdl.handle.net/1884/37621.

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Orientador : Dr. Antonio Sálvio Mangrich
Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa: Curitiba, 12/03/2015
Inclui bibliografia
Área de concentração: Inorganic Chemistry
Resumo: A nanotecnologia é uma ciência de engenharia em que o objetivo é desenvolver procedimentos e estruturas em nanoescala, com novas propriedades que podem oferecer soluções para muitos problemas atuais. Nesta pesquisa, descrevemos a síntese de nanopartículas de óxido de ferro superparamagnético (Fe3O4). As nanopartículas de óxido de ferro contêm um núcleo de óxido de ferro, que é cercado por um escudo de ligantes. O escopo deste trabalho foi a preparação de nanopartículas superparamagnéticas baratas e revestidas com extrato de tanino condensado pirolisado extraído de Acacia mearnsii formando nanopartículas estruturadas num núcleo-camada de cobertura, usando um processo de coprecipitação de passo único. Extrato seco de tanino de foi por terra e blindados (usando uma peneira de malha-80), e 200 g por litro foi adicionado a uma solução aquosa contendo cloreto férrico e cloreto ferroso relação molar de 2:1 em um meio básico de pH = 10. A mistura foi agitada vigorosamente por 30 minutos. Após a formação de precipitado, ele foi separado por centrifugação e depois de secar o precipitado foi pirolisado na temperatura desejada 400 °C ou 700 °C, respectivamente, a taxa de 5 ° C/min por 6 h. A caracterização do material preparado foi realizada utilizando espectroscopia de infravermelho com transformada de Fourier (FTIR), microscopia eletrônica de varredura (MEV), microscopia eletrônica de transmissão (TEMPLETON et al.), difração de raios x (XRD) e análise de Brunauer-Emmett-Teller (BET). As nanopartículas superparamagnéticas de óxido de ferro em tanino pirolisado (SPMIOBNPs) apresentaram tamanhos médios na faixa de 20-35 nm determinados com a ajuda da XRD e equação de Scherrer. As análises de BET e SEM confirmaram que a superfície das SPMIOBNPs apresentavam estrutura porosa, com multicamadas de microporos e isoterma do tipo H(III). As SPMIOBNPs preparadas mostraram atração muito forte em direção de campo magnético externo, usando espectroscopia de EPR, ou disco do ímã de neodymium. As propriedades magnéticas revelaram que os SPMIOBNPs eram superparamagnéticas, com saturação de magnetização de 32 emu/g a 300 K utilizando magnetômetro SQUID. O desempenho das SPMIOBNPs na limpeza de águas mostraram um bom resultado na remoção de cromo hexavalente [Cr(VI)] da água contaminada. Os resultados mostraram que a adsorção de Cr(VI) pelas SPMIOBNPs era dependente pH, sendo que as maiores adsorções se deram no menor pH da solução de valor 2. O estudo por espectroscopia de fotoeletrônica de raios x (XPS) mostrou que que a maior parte do Cr(VI) adsorvido foi reduzido a Cr(III). Neste estudo, podemos concluir que SPMIOBNPs têm o potencial de remoção de cromo hexavalente de águas residuais. O equilíbrio cinético do processo de sorção também foi investigado. A sorção de Cr(VI) pelas SPMIOBNPs preparadas seguiu o modelo cinético de pseudo - segunda ordem sugerindo que a taxa de reação de sorção depende de dois parâmetros, que podem ser a concentração do sorbato e dosagem do adsorvente. Segundo modelo de ordem indica que ’Quimissorção’ ocorreu durante o processo de adsorção ou seja, uma nova espécie químicos foram criados na superfície do adsorvente. Palavras-chave: Nanotecnologia, superparamagnético, biocarvão, tanino, co-precipitação, cromo hexavalente.
Abstract: Nanotechnology is an engineering science in which the aim is to develop procedures and structures at the nanoscale, with novel properties that might offer solutions to many current problems. In this research, we describe the synthesis of superparamagnetic iron oxide (Fe3O4) nanoparticles. Iron oxide nanoparticles contain a core of iron oxide which is surrounded by a shell of ligands. The scope of this work is a preparation of cheap superparamagnetic nanoparticles and coating them with extract of condensed tannin extract of Acacia mearnsii to form core-shell structured biochar nanoparticles, using a single step co-precipitation process. Dry tannin extract of was ground and screened (using an 80-mesh sieve), and 200 g per liter was added to an aqueous solution containing ferric chloride and ferrous chloride 2:1 molar ratio at a basic medium of pH =10. The mixture has been vigorously stirred for 30 minutes. After the formation of precipitate it was separated by centrifugation and after drying the precipitate was pyrolysed on desired temperature 400 °C and 700 °C respectively at a rate of 5 °C/min for 6 h. Characterization of this material (acronym: SPMIOBNPs) was performed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy , X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) analysis. The SPMIOBNPs particles produced were contained iron oxide nanoparticles with average sizes in the range of 20-35 nm determined with help of XRD and Scherrer equation. The XRD diffractogram suggest the. SEM and BET analysis confirm its porous, multilayer micropores structure surface with H(III) type of isotherm. The FTIR analysis give an idea about the changes take place in the structure after pyrolysis attributing the formation SPMIOBNPs with characteristic functional groups. SPMIOBNPs prepared shows very strong attraction toward external magnetic field using a disc of neodymium magnet. The magnetic properties revealed that the SPMIOBNPs were superparamagnetic, with a saturation magnetization of 32 emu/g at 300 K using vibrating sample magnetometer SQUID. The performance of the SPMIOBNPs show a good result in the removing of hexavalent chromium Cr(VI) from contaminated water. The detection of total chromium in the solution was analyzed with the help of flame atomic absorption and hexavalent chromium was done with the help of 1,5- diphenylcarbohydrazide method. Equilibrium, kinetics, of the sorption process were also investigated which show some reduction of Cr(VI) to Cr(III). The results showed that Cr(VI) adsorption on SPMIOBNPs was dependent on lower pH of the solution i.e. 2. The X-ray photoelectron spectroscopy (XPS) study showed that during Chromium adsorption, some amount Fe(II) was transformed into Fe(III) by the redox reaction and Cr(VI) species were reduced to Cr(III) species. In this study we conclude that SPMIOBNPs have potential in removal of chromium hexavalent from waste water. The sorption kinetics of Cr(VI) onto SPMIOBNPs are followed the pseudo-second order kinetic model suggesting that the sorption reaction rate depends on two parameters, which might be the sorbate concentration and sorbent dosage. Second order kinetic model indicates that ’Chemisorption’ took place during the adsorption process i.e. a new chemical species were created at the adsorbent surface. Key-words : Nanotechnology, superparamagnetic, biochar, tannin, coprecipitation, hexavalent chromium.

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32

Mansoori, Behzad. "Tannin/protein interactions : effects on digestibility coefficients and endogenous losses in broilers". Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301201.

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Tannic acid was shown to increase weight loss, and total excretion of endogenous dry matter, nitrogen, uric acid, amino acids, energy and minerals (calcium, magnesium and phosphorus) in broilers. There was a positive linear correlation between the amount of tannic acid dosed, and the weight and endogenous losses. A variation in the excretion of individual amino acids and minerals in response to dosed tannic acid was also noted. The mechanisms of increased endogenous losses of the birds as influenced by tannic acid were investigated and discussed. Feeding gelatin and casein significantly reduced the adverse effects of tannic acid on weight and endogenous losses. There were also significant improvements in digestibility coefficients and metabolisable energy values of protein in tannic acid dosed birds when the amount of the protein increased. Although in birds not dosed with tannic acid, casein had a higher digestibility and metabolisable energy compared to gelatin, tannic acid dosed birds showed greater improvements in digestibility coefficients when receiving gelatin. The above contrast was possible because of the higher affinity of gelatin for tannic acid compared to the casein. Polyethylene glycol (PEG) was shown to alleviate the weight and endogenous losses of tannic acid dosed birds not receiving protein. Polyethlene glycol also reduce the endogenous losses as well as improved the digestibility coefficients and metabolisable energy values of tannic acid dosed birds when receiving the lower amounts of gelatin (6g) or casein (6 and 12g). However, the effect of PEG was less apparent in tannic acid dosed birds receiving the higher amounts of gelatin (12 and 18g) and casein (18g). In conclusion, the presence of tannins in poultry diets are likely to increase the endogenous losses of organic materials as well as minerals, but this is likely to depend on the type and amount of diet ingredients such as proteins and additives (eg. PEG).

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33

Efhamisisi, Davood. "Preservation of plywood against biological attack with low environmental impact using tannin-boron preservative". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS235/document.

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Une étude expérimentale a été menée afin de protéger des attaques biologiques des contreplaqués faits d'essences non durables (hêtre et peuplier), et ce, avec un faible impact environnemental. Des produits de protection à base de tannins et de bore, nouvellement développés afin de réduire le lessivage du bore, ont été sélectionnés pour ce but. Ce système a été utilisé pour protéger les contreplaqués selon deux approches : (1) au niveau de la colle pour remplacer les adhésives à base de formaldéhyde et coller les plis, (2) en traitement des plis avec des formulations plus diluées, les plis étant collés avec des adhésifs mélamine-urée-formaldéhyde. Les données expérimentales de cette thèse peuvent être classées en trois grands groupes : essais chimiques et thermomécaniques des colles tannin-bore, mesure des propriétés physiques et mécaniques, de la résistance biologique avant et après vieillissement des différents panneaux. Les essais chimiques sur les colles tannin/hexamine ont montré que l'addition de bore sous forme d'acide borique peut contribuer à plus de liaisons inter-flavonoids et à ouvrir les cycles pyranes ce qui accélère les réactions de polymérisation. Des analyses thermomécaniques sur les colles contenant des tannins de mimosa et de quebracho ont confirmé que l'addition d'acide borique (1) abaissait le temps et la température de prise, et (2) augmentait les valeurs du module d'élasticité de la colle. L'addition d'une quantité optimale d'acide borique dans la colle à base de tannin augmente les propriétés physiques et la résistance au cisaillement. Une charge excessive d'acide borique (10%) dans la colle est la cause de pertes de propriétés mécaniques et physiques. Bien qu'en faible quantité, l'introduction de l'acide borique dans la colle de tannin amène une protection efficace contre l'attaque fongique, même après un lessivage selon l'EN 1250-2. Les résultats des essais termites montrent que l'acide borique contenu dans la colle cause le plus faible taux de survie des insectes et de perte de masse, mais présentent un fort degré d'attaque selon une cotation visuelle. Aucune amélioration n'a été obtenue lors d'un essai de choix après lessivage. Les contreplaqués faits de plis traités par des solutions tannin-bore ont montré des résistances au cisaillement plus faibles, mais toujours dans les gammes requises pour des applications en atmosphère humide. Des résultats satisfaisants ont été obtenus par les réseaux polymères de tannins, même après une lessivage sévère, vis-à-vis de l'attaque fongique. Les contreplaqués faits de plis traités à l'acide borique seul ont présenté une sensibilité importante à l'attaque biologique après un lessivage. Les résultats des essais termites ont montré un faible taux de survie des insectes et de perte de masse, même après un lessivage sévère, pour les contreplaqués avec des plis traités par des systèmes tannin-bore. Les résultats d'un essai de choix a montré que les termites préféraient se nourrir des témoins quand l'alternative proposée était des échantillons traités avec des systèmes tannin-bore
An experimental investigation was conducted to protect plywood panels made of perishable wood species (beech and poplar) against biological attacks with low environmental impact. The newly developed tannin-boron preservative which was proposed to reduce the leaching of borates was selected for this purpose. This system was used to protect plywood with two approaches: (1) in the glue line to replace formaldehyde based adhesives and gluing wood veneers, (2) pretreatment of wood veneers with the diluted formulations and bonded with melamine-urea-formaldehyde resin The research data in this thesis were obtained from three main groups of experiments: chemicals and thermomechanical testing on the tannin-boron resin, measuring physical and mechanical properties, and different biological tests before and after leaching processes. The chemicals testing on the tannin/hexamine adhesive showed that the addition ofboron, in the form of boric acid, can contribute more inter-flavonoid linkages and the opening of pyran rings which leads to the acceleration of polymerization reactions. Thermomechanical analysis on the adhesives of mimosa and quebracheo tannins confirmed that the addition of boric acid (1) lowered time and temperature of hardening, (2) and increased modulus of elasticity values of the adhesive. The addition of optimal boric acid into the tannin adhesive upgraded physical properties and tensile shear strength. An excess loading of boric acid (10%) in the glue line caused imperfect physical and mechanical features. Despite the low uptake of boric acid but its addition into the tannin glue provided effective resistance against fungal attack even after mild leaching test according to the EN 1250-2. The results of termites test showed that increase in the boric acid content of the adhesive caused the lower survival rate and the weight loss but samples underwent the high level of attack. No improvement against termite attack was obtained after leaching by a choice feeding test. The plywoods made of pretreated veneers by tannin-boron solutions showed partially lower tensile shear strength but still in the range of standards requirements for the humid applications. The satisfactory results were obtained even after severe leaching test against fungal attack with a strong polymeric network of tannin. The control plywoods made of pretreated veneers with boric acid alone solutions presented significant sensitivity against biological attack after leaching test. The results of termite tests showed the lower survival rate and the weight loss even after severe leaching test for the plywoods made of pretreated veneers with tannin-boron systems. The results of choice feeding test showed that termites preferred feeding from the controls when alternative samples were treated with the tannin-boron system. In general the evidence from this study suggests that tannin-boron system can significantly slow down the leaching of boron and it rendered high potential to preserve plywood

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Corrêa, Stefane Santos. "Qualidade dos couros de tilápia, corvina e pescada amarela". Universidade Estadual do Oeste do Paraná, 2017. http://tede.unioeste.br/handle/tede/3140.

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The leather tanning of fish is a way of alleviating the damage caused by chromium salts to the environment. this work had as objective evaluate the process of tanning leather in the skins in corvina and pescada amarela from fishing made in the northern region of Brasil and tilápia origin of fish farming. The species caught in the fishing of the region present the potential for use in the tanning because they are large, which allows you to add value to the final product. The skins were to the same tanning process not differing in any of its stages. to determine the efficiency of the process, the skins of corvina, pescada amarela and tilapia were submitted to the resistence test the traction, stretching and progressive tear in the longitudinal and transverse directions of the body of the fish and the physical-chemical analysis. the resistance tests the traction and stretching were satisfactory for manufacturing of products and clothing. However, suggests improve the grease of the tanning process.
O curtimento vegetal de couro de peixes é uma forma de amenizar os danos causados pelos sais de cromo ao ambiente. Este trabalho teve como objetivo avaliar o processo de curtimento nas peles de corvina e pescada amarela oriundas da pesca realizadas na região norte e tilápia oriunda de piscicultura do estado do Paraná. As peles foram submetidas ao mesmo processo de curtimento vegetal não diferindo em nenhuma das suas etapas. Para determinar a eficiência do processo, as peles de corvina, pescada amarela e tilápia foram submetidas à análise físico-química, ao teste de resistência à tração, alongamento e rasgamento progressivo no sentido longitudinal e transversal do corpo do peixe. Foi realizada a analise histológica dos couros, para se analisar a estrutura das fibras. Os testes de resistência à tração e alongamento foram satisfatórios, comprovando que as peles das espécies capturadas na pesca da região norte do Brasil apresentam potencial para utilização no curtimento, apresentando qualidade apropriada para confecção de produto, vestuário e calçado. Entretanto, sugere-se aprimorar a etapa de engraxe do processo de curtimento.

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Ansong, Godfred. "Analysis of plant polyphenols by high performance liquid chromatography/mass spectrometry and protein binding". Oxford, Ohio : Miami University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1083081905.

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36

Santiago-Medina, Francisco José. "Tanins condensés pour mousses rigides et nouvelles réactions de réticulations des matériaux polyphénoliques". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0248/document.

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Une alternative aux produits industriels de type phénol ou résorcinol peut être des tanins ou de la lignine. Les deux sont des polyphénols naturels, le tanin est extrait de différentes parties de plantes, tandis que la lignine est habituellement obtenue comme sous-produit dans les industries papetières. Ces deux produits sont la base principale sur laquelle j’ai travaillé pendant le développement de cette thèse. Dans une première partie, une étude de caractérisation et de différenciation entre différents tannins ayant la même origine mais que présentent un comportement différent lorsqu'ils sont utilisés dans la même application dans les mêmes conditions a été effectuée. Cette étude met en évidence la GPC comme technique fondamentale pour la différenciation des tanins de quebracho sulfités. D'autre part, les interactions entre différentes substances avec du tanin et de la lignine ont été étudiées. Comme l’étude de la réaction entre les diamines (telles que l'hexaméthylènediamine) avec du tanin et de la lignine pour obtenir des résines polycondensées. En outre, dans cette section ont été obtenus des polyuréthanes avec au moins 70% de substances naturelles dans leur préparation sans utiliser d'isocyanate dans le procédé. De plus, des aldéhydes dérivés de la lignine, comme la vanilline, ont été utilisés avec le tanin de pin pour la fabrication d'adhésifs dans la préparation de panneaux de particulaires, obtenant des résultats satisfaisants selon les normes européennes et des substances complètement naturelles. Enfin, dans le cadre d'un projet industriel les étapes initiales pour le développement d'une mousse de tanin rigide applicable par projection pour l'isolation thermique des bâtiments ont été réalisées. Lorsqu'un nouveau système de moussage mécanique a été développé pour des mousses de tanin basées sur des mousses de lutte contre incendie à base de tanin ou dans les mousses des opérations d’ouverture du tunnel, ce nouveau système de moussage évite les problèmes de retrait lors de la formation de la mousse
An alternative to industrial phenol or resorcinol industrial products may be tannins or lignin. Both are natural polyphenols, the tannin is extracted from different parts of plants, while lignin is usually obtained as a secondary product in the pulp and paper mill. These two products are the main basis on which I have worked during the development of this thesis. In a first part, a study of characterization and differentiation between different tannins with the same origin and that present a different behavior when used in the same application under the same conditions has been done. Highlighting the GPC as a fundamental technique for the differentiation between sulphited quebracho tannins. On the other hand, the interactions between different substances with tannin and with lignin have been studied. As the study of the reaction between diamines (such as hexamethylenediamine) with tannin and lignin to obtain a polycondensed resins. Also, in this section have been obtained polyurethanes with at least 70% of natural substances in their preparation without using any isocyanate in the process. In addition, aldehydes derived from lignin, such as vanillin, have been used next to pine tannin for the manufacture of adhesives in the preparation of particleboards, obtaining satisfactory results according to European standards and from completely natural substances. Finally, within an industrial project the initial steps have been carried out for the development of a rigid tannin foam applicable by projection for the thermal insulation of buildings. Where a new mechanical foaming system has been developed for tannin foams based in fire-fighting foams or in the foams of the tunneling operations, this new system of foaming avoids the problems of shrinkage during the formation of the foam

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37

Rousserie, Pauline. "De la synthèse des flavanols aux tanins du vin : quelle place pour les pépins de raisin ?" Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0320.

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La maturité phénolique de la baie tient compte de la teneur en composés phénoliques de la baie, mais également de leur potentiel d’extractibilité dont dépend leur diffusion dans le vin. Même si ce phénomène commence à être assez bien connu, et maîtrisé pour les parties charnues de la baie, très peu de travaux portent sur la maturité phénolique du pépin. Or, la teneur en tanins des pépins pouvant, dans certains cépages, représenter jusqu’à dix fois celle de la pellicule, ils constituent une part importante des tanins de la baie. Ainsi, la connaissance parfaite de la composition tannique des pépins, de leur biosynthèse, de leur localisation ainsi que la maîtrise de leur extraction durant la vinification constituent des enjeux majeurs pour maitriser la qualité du vin fini.Notre travail, combinant des approches chimiques, moléculaires, microscopiques et œnologiques, apporte de nouvelles connaissances sur les teneurs, la biosynthèse, la localisation et l’extractibilité des tanins de pépins permettant d’élaborer un outil d’évaluation de la maturité des pépins (dénommé SCANPEP) pour aider le viticulteur dans le choix de la date de vendange et le vinificateur dans ses choix d’itinéraires de vinification.Ainsi, nos travaux ont mis en évidence une conservation du métabolisme phénolique des pépins de raisin commun à tous les cépages étudiés. Les teneurs en tanins des pépins présentent un profil en cloche jusqu’à véraison, suivie d’une période de dégradation et/ou perte d’extractibilité jusqu’à environ 3 semaines avant la vendange. Le millésime, le cépage et la nature du sol ne modifient pas ce profil mais peuvent impacter soit le degré de polymérisation, soit le pourcentage de galloylation, soit les teneurs finales en proanthocyanidines. La synthèse des flavanols, réalisée au niveau des plastes et des parois cellulaires, conduit à une accumulation tissulaire progressive des tanins, partant du bec jusqu’au corps du pépin, et des tissus les plus externes vers les plus internes. Enfin, par une originale approche de nano-vinification, nos résultats ont permis de démontrer que les variations du potentiel d’extractibilité des tanins de pépins ne pouvaient s’expliquer uniquement par les variations de maturité de ce dernier, soulevant ainsi l’importance de la composition de la matrice vin dans le phénomène d’extractibilité des tanins de pépins
In oenology, the notion of berry phenolic maturity is related to the phenolic content of the berry, but although to their extractability capacity in wine. Nowadays, this phenomena starts to be well understood for berry fleshy parts. Nevertheless, despite the fact that seed tannins content can be ten-fold higher than the skin one, there is few works facing seed phenolic maturity. In this context, it appears clear that the perfect knowledges of the evolution of seed tannins content, biosynthesis, location and extractability all along the berry development will be helpful to control finale wine quality.Our work, which is combining chemistry, molecular, microscopy approaches bring knew knowledges in order to better characterize the seed phenolic maturity. Drawing on this expertise, we have elaborated a new indicator of seed phenolic maturity (ScanPep), useful to estimate the harvest date, but although to choose winemaking itinerary.This study brings to light that seed phenolic metabolism is conserved through vine species. Indeed, the evolution of seed content all along the berry development seems to be shared by all the studied seeds: an augmentation of seed tannins content until veraison, followed by a period of degradation/ loss of extractability until three weeks before harvest. Vintages, species or soil natures seems to not affect this profile, but can affect structural tannins characteristics such as the percentage of galloylation, the degree of polymerisation or the finale tannins content. The flavanols synthesis which is realized in plastids and cell walls leads to a progressive tissue accumulation of tannins in seed: from seed beak to seed body, and from extern to intern tissues. Finally, by an original approach of nano-vinification, we have proved that variations of seed tannins extractability cannot be explained only by variations of seed maturity, raising the importance of wine matrix content in seed tannins extractability

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38

Díaz, Muñoz Jorge Gerardo. "Development of sustainable tannin with low carbon footprint to obtain high quality leather". Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/145382.

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Today we are experiencing an "eco friendly boom"; which includes the developing of ecological processes that have a smaller impact in the environment. This is the reason that prompted me to carrying out this thesis; the aim is to use a vegetable extract as a sustainable product for the pre-tanning processes. This study considers the use of the fruit of the Tara tree as a raw material source of tannins with low carbon footprint and proposes alternatives to avoid or reduce the use of commercial vegetable extracts, synthetic products and mineral salts that require non sustainable processes. Various experimental designs have been developed as to obtain new tailored Tara tannins by both chemical and physical modification, in order to obtain a higher percentage of tannins, and therefore improve its tanning capability, also reducing the astringency and improving the penetration of the tannin molecules through the leather structure. In chemical modifications, several aqueous extractions at different temperatures and combined with some chemicals, have been developed and optimized in order to increase the tannin content and reduce the astringency. The degree of hydrolysis has controlled by measuring the Gallic acid content by means of HPLC (High performance liquid Chromatography). In the physical modification part, the Tara has been milled and sieved, at several particle sizes, with the aim of obtaining a smaller molecular size. Both chemical and physical modifications were tested in hides, in a wet-white pre-tanning process, combining them with the fewest possible commercial vegetable extracts and syntans. The formulations have been optimized by experimental design. All the resulting leather products and final baths have been analyzed with physical and chemical tests respectively, to determine if they comply with the parameters established by the IULTCS (International Union of Leather Technologists and Chemists Societies). Finally, a life cycle assessment has been developed, in order to determine the environmental improvement of the new modified product, obtained in this thesis. This thesis is also supported with articles published in magazines specialized in the Leather sector. There are two articles published in the Journal of the American Leather Chemists Association (JALCA), named: *Low carbon products for the design of innovative leather processes. Part I: determination of the optimal chemical modification of tara. . (JALCA, Vol. 108, pag. 386-391, 2013) *Low carbon products for the design of innovative leather processes. Part II: determination of the optimal physical modification of tara. (JALCA, Vol. 109, pag. 25-31, 2014) One article pending to be published in the Journal of AQEIC (Spanish Leather Chemists Association) Application of Sustainable tannins with Low carbon footprint,And presented in the 62nd Congress of AQEIC, Lorca (Murcia), May 10th and 11th, 2013 Presentation: "Aplicación de taninos sostenibles con baja huella de carbono"

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39

Häring, Dieter Adrian. "Determinants of tannin concentrations in forage plants : agronomic potential of tanniferous forage plants /". Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17237.

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40

Melo, dos Santos Leticia. "Enzymatic polymerisation in situ of depolymerised mimosa tannin applied to stabilisation of collagen". Thesis, University of Northampton, 2017. http://nectar.northampton.ac.uk/9802/.

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Vegetable tannins used in tanning of hides and skins are limited to surface reactions by their large molecular weights. The molecular weight reduces penetration into the skin and lowers the thermal stability or tanning effect. Investigation into the utilisation of small phenolic compounds such as catechin to improve penetration with subsequent in situ enzymecatalysed polymerisation may provide a novel and alternative tanning agent. In this research, catechin was oxidised by enzymatic catalysis using laccase, with the polymerisation confirmed by FT-IR and UHPLC. Tanning experiments were undertaken to measure the effect of laccase-catalysed polymerisation of catechin in the thermal stabilisation of collagen, by monitoring the change in shrinkage temperature between the treated and untreated sample of hide powder (ΔTs). This study demonstrates that the stabilisation of collagen (ΔTs) is increased with the use of in situ enzyme-catalysed polymerisation. Depolymerisation of condensed tannins is presented as an alternative source of low molecular weight phenolics to be applied in the stabilisation of collagen. In this research, mimosa tannin from the Black Wattle tree (Acacia mearnsii) was used in the depolymerisation process. Preliminary experiments on depolymerisation were undertaken using the methods laccase-mediator system and L-cysteine in mild acidic medium, both showing unsatisfactory results. Acid-catalysed depolymerisation followed by nucleophile addition is a common analytical method for determining the degree of polymerisation of proanthocyanidins. The acid-catalysed depolymerisation method was scaled-up, with the addition of pyrogallol as a nucleophile trapping agent, and powdered depolymerised mimosa was obtained. Data show an increase in the monomeric content and decrease in percentage of condensed tannins for the acid-catalysed process, indicating the potential of the depolymerisation of mimosa tannin in obtaining environmentally friendly sources of low molecular weight phenolic compounds for use in large scale/industrial applications. The depolymerised product was applied in the stabilisation of hide powder and goat skin. Using hide powder, data show that the laccase-assisted polymerisation of the depolymerised mimosa reached higher values of ΔTs in comparison with the conventional process employing unmodified mimosa. Using goat skin, the new process achieved similar values of ΔTs as the conventional process. In order to obtain similar results for goat skin as obtained with hide powder, an optimisation may be carried out. Therefore, data obtained demonstrates the potential of the new route in vegetable tanning of leather.

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PHURIRAGPITIKHON, JENJIRA. "Development of tannin-derived porous carbons with tailored porosity for carbon dioxide adsorption". Kent State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=kent1611592776993541.

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42

Williams, Christina Marie. "Assessment of Ruminal Fermentation Characteristics of Condensed Tannin-Containing Forages Using Continuous Cultures". DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/773.

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Two independent studies were conducted to assess the effects of feeding condensed tannin (CT)-containing forages to continuous cultures to evaluate their impacts on ruminal fermentation and digestibility, with an emphasis on methane (CH4) and ammonia-N (NH3-N) production. In Chapter 3, treatments consisted of: 1) 100% alfalfa hay (AH), 2) 50% AH and 50% birdsfoot trefoil hay (dry matter (DM) basis; AHBFTH), and 3) 100% birdsfoot trefoil hay (BFTH). Three replicated runs lasted 8 d each, with the first 5 d allowed for microbial adaptation to the diets, and 3 d for data collection and sampling. Methane, neutral detergent fiber (NDF) degradability, and total volatile fatty acid (VFA) production and profiles were not affected by the dietary treatments. However, NH3-N concentration and flow were reduced when replacing the AH with the BFTH. It was concluded that feeding a CT-containing diet (BFTH) increased the in vitro N utilization. In Chapter 4, five total mixed ration (TMR) diets were evaluated, each containing a different forage source as hay: 1) alfalfa (AHT), 2) cicer milkvetch (CMVHT), 3) Norcen birdsfoot trefoil (NBFTHT), 4) Oberhaunstadter birdsfoot trefoil (OBFTHT), and 5) sainfoin (SFHT). Total VFA production and acetate molar proportion were not influenced by treatments. However, molar proportion of propionate increased by the CMVHT, and decreased by the SFHT. Acetate to propionate ratio decreased with the CMVHT and the OBFTHT, but increased with the SFHT when compared to the AHT. Digestibilities of DM and NDF were not influenced by dietary treatments. Total CH4 production decreased by all treatments when compared to the AHT, whereas CH4 production expressed as mM per g of NDF digested was reduced only by the CMVHT and the OBFTHT. Ammonia-N concentration decreased when feeding the CMVHT and the SFHT. Feeding the CMVHT decreased ruminal concentration of C18:0, while ruminal C18:1 cis and trans isomers were greatest with the CMVHT. Because these effective tannin-free and tanniniferous legumes did not have negative impacts on ruminal fermentation, they can maintain potential productive performance of lactating dairy cows when fed as main forage sources in TMR diets.

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SOUZA, Rayanne Thalita de Almeida. "Potencial taninífero da jurema preta e do angico vermelho avaliado por diferentes métodos". Universidade Federal Rural de Pernambuco, 2015. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6464.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The chemical characterization and the determination of secondary compounds in native legumes are very important for enabling better use these plants as raw material for various segments in the industry. This study aimed to characterize the chemical-bromatological bark and leaves with stems of two native legumes, quantify and characterize the fractions of condensed tannins. The species were collected: ‗Jurema preta‘ (Mimosa tenuiflora (Willd) Poiret) and ‗Angico vermelho‘ (Anadenanthera macrocarpa (Benth) Brenan.), in three cities of the northeastern semiarid: Arcoverde / PE, Patos / PB and Delmiro Gouveia / AL. The chemical analysis performed were: dry matter (DM), mineral matter (MM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF), neutral detergent insoluble nitrogen (NDIN) and acid detergent insoluble nitrogen (ADIN) and lignin digested in acid (LDA) and condensed tannins by the methodologies of HCl-Butanol and phenols by the precipitable protein (PPP). The chemical-composition data and fractions of condensed tannins were analyzed using descriptive statistics, and to compare the methods of quantification of the total condensed tannins was used the t test, at 5% significance level. They were obtained values of DM, CP and PIDA to the leaves with stems of Jurema preta e angico vermelho respectively: 435.2; 428.83 g / kg MN, 159.3; 199.6 g / kg DM, 60.1; 66.64 g / kg CP. As for total condensed tannins through the HCl-Butanol methodologies and phenols by precipitable protein, respectively, 165.32 and 258.70 g / kg DM for leaves with stems and 456.64 and 360.97 for the shells. And for the Angico vermelho: 52.62 and 162.26 g / kg DM to the leaves with stems and 168.04 and 376.03 for the shells. Concluding that a portion of the crude protein of legumes studied is unavailable because it is connected to the ADF and condensed tannins. Jurema preta was the species that showed higher total condensed tannins content. And the PPP methodology is considered the most efficient quantification of condensed tannins.
A caracterização química e a determinação de compostos secundários em leguminosas nativas são de grande importância por possibilitar um melhor uso dessas plantas como matéria prima para diversos seguimentos na indústria. A realização deste estudo teve como objetivo caracterizar químico-bromatologicamente as cascas e folhas com hastes de duas leguminosas nativas, quantificar e caracterizar as frações de taninos condensados. Foram coletadas as espécies: Jurema preta (Mimosa tenuiflora (Willd) Poiret) e Angico vermelho (Anadenanthera macrocarpa (Benth.) Brenan) em três municípios do Semiárido nordestino: Arcoverde/PE, Patos/PB e Delmiro Gouveia/AL. As análises químico-bromatológicas realizadas foram: matéria seca (MS), matéria mineral (MM), proteína bruta (PB), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA), nitrogênio insolúvel em detergente neutro (NIDN) e nitrogênio insolúvel em detergente ácido (NIDA) e lignina digerida em ácido (LDA) e de taninos condensados pelas metodologias do HCl-Butanol e a dos fenóis precipitáveis por proteína (PPP). Os dados químico-bromatológicos e frações de taninos condensados foram analisados através de estatística descritiva, e para a comparação dos métodos de quantificação dos taninos condensados totais foi utilizado o teste t, ao nível de 5% de significância. Foram obtidos valores de MS, PB e PIDA para as folhas com hastes de jurema preta e angico vermelho, respectivamente: 435,2; 428,83 g/kg MN, 159,3; 199,6 g/kg MS, 60,1; 66,64 g/kg PB. Já para taninos condensados totais através das metodologias do HCl-Butanol e Fenóis precipitáveis por proteína, respectivamente: 165,32 e 258,70 g/kg MS para folhas com hastes e 456,64 e 360,97 para as cascas. E para o Angico vermelho: 52,62 e 162,26 g/kg MS para as folhas com hastes e 168,04 e 376,03 para as cascas. Concluindo que, uma parte da proteína bruta das leguminosas estudadas está indisponível, pois se encontra ligada à FDA e taninos condensados. A Jurema preta foi a espécie que apresentou maiores teores de taninos condensados totais. E a metodologia PPP é considerada a mais eficiente na quantificação de taninos condensados.

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Rira, Moufida. "Les tanins hydrolysables et condensés : une piste pour la réduction de la production du méthane entérique par les ruminants en mileu tropical Intake, total-tract digestibility and methane emissions of Texel and Blackbelly sheep fed C4 and C3 grasses tested simultaneously in a temperate and a tropical area Ruminal methanogens and bacteria populations in sheep are modified by a tropical environment Potential of tannin-rich plants, Leucaena Leucocephala, Glyricidia sepium and Manihot esculenta, to reduce enteric methane emissions in sheep Potential of tannin-rich plants, Leucaena Leucocephala, Glyricidia sepium and Manihot esculenta, to reduce enteric methane emissions in sheep Potential of tannin-rich plants for modulating rumen microbes and ruminal fermentation in sheep Methanogenic potential of tropical feeds rich in hydrolyzable tannins". Thesis, Université Clermont Auvergne‎ (2017-2020), 2019. http://www.theses.fr/2019CLFAC065.

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En zone tropicale, la production de lait et de viande par les ruminants est limitée par une faible disponibilité et une qualité médiocre des fourrages. A ces contraintes alimentaires s’ajoute l’impact environnemental lié en particulier aux émissions de méthane entérique par les ruminants. L’objectif de cette thèse était de comparer la production de méthane en milieu tempéré et en milieu tropical, puis de valoriser des fourrages tropicaux connus pour leur richesse en tanins dont les propriétés anti-méthanogènes sont reconnues, et qui peuvent réduire l’impact environnemental sans compromettre la productivité animale. Cette thèse comporte trois expérimentations distinctes. La première consistait en une étude in vivo visant à déterminer si les différences de digestibilité, de production de méthane, de fermentation et d’écosystème microbien du rumen observées entre les zones tempérées et tropicales proviennent de l’environnement (site d’expérimentation en milieu tempéré ou tropical), du fourrage (produit en zone tempérée ou tropicale), ou du génotype ovin (race de zone tempérée ou tropicale). Les résultats ont montré que les différences sont liées en priorité à la nature du fourrage, et sont influencées par les interactions entre génotype, caractéristiques du fourrage et environnement. La seconde expérience consistait à étudier l’effet de plantes riches en tanins condensés (feuilles de Gliricidia sepium, Leucaena leucocephala, Manihot esculenta) sur la production de méthane, l’ingestion et la digestibilité de la ration, les fermentations et l’écosystème microbien du rumen. Un essai in vivo a montré que l’incorporation de ces plantes à raison de 40% du régime d’ovins sous forme de granulés permettait de réduire le méthane entérique sans effets indésirables sur la digestibilité et la fermentation ruminale. Un essai in vitro a montré que le principal facteur de la réponse a été la dose de tanins condensés plutôt que la source. La troisième expérience consistait en l’étude in situ et in vitro du pouvoir anti-méthanogène et de la dégradation dans le rumen de plantes riches en tanins hydrolysables (feuilles et gousses d’Acacia nilotica) ou en tanins condensés (feuilles de Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala, Manihot esculenta, Musa spp). Les résultats obtenus suggèrent que les tanins hydrolysables conviennent mieux à la réduction des émissions de méthane que les tanins condensés car ils inhibent fortement la production de méthane sans effets négatifs marqués sur la fermentation ruminale. Les effets des tanins sur la production de méthane et la fermentation dans le rumen ont été en partie expliqués par le devenir des différentes fractions des tanins (libres, associés aux protéines ou aux fibres) dans le rumen. L’association de plantes riches en tanins hydrolysables et en tanins condensés ne parvient pas à dégager de possibles synergies entre ces de types de molécules. Ce travail a permis de montrer qu’il était possible de réduire les émissions de méthane entérique par les ruminants en milieu tropical par la consommation de fourrages riches en tanins hydrolysables sans compromettre les processus digestifs dans le rumen ; la diminution de la méthanogenèse avec les tanins condensés présente plus de risque de réduire les fermentations
In tropical areas, dairy and meat production from ruminants is limited by low availability and poor quality of forages. In addition to this dietary constraint, the emission of enteric methane under these less productive conditions is proportionally larger than under temperate conditions. The aim of this work is i) to compare enteric methane production in tropical and temperate environments, and ii) to promote tropical forages rich in hydrolysable or condensed tannins having anti-methanogenic properties that could reduce the environmental impact without compromising animal productivity. This work includes three separate studies. The first one was an in vivo study aiming to determine the origin of the differences of digestibility, methane production, ruminal fermentation and microbial ecosystem between tropical and temperate countries using as variables: the site of the experiment (tropics or temperate area), the type of forage (grown in the tropics or in temperate areas); and the animal genotype (tropical or temperate). Results showed that differences are mainly due to forages, but with interactions between nature of forages, environment and genotype. The objective of the second study was to determine the effect of plants rich in condensed tannins (leaves of Gliricidia sepium, Leucaena leucocephala, and Manihot esculenta) on methane production, intake, digestibility, ruminal fermentation and microbial ecosystem. An in vivo trial demonstrated that the inclusion of 40% of these plants as pellets in sheep diet reduced enteric methane without compromising the nutritive value of the diet. An in vitro trial showed that the response to tannins was more due to tannin concentration than to the plant species. In the third study, plants rich in hydrolysable tannins (leaves and pods of Acacia nilotica) or in condensed tannins (leaves of Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala, Manihot esculenta, Musa spp) were studied for their anti-methanogenic properties and their ruminal degradation in an in situ and an in vitro trial. Results suggest that hydrolysable tannins are more suitable than condensed tannins for mitigating methane emission because of a strong reduction in methane production without negatively affecting ruminal fermentation. These results have been partly explained by the fate of the different fractions of condensed tannins (free, protein-bound and fibre-bound) in the rumen. The association of plants rich in hydrolysable tannins with plants rich in condensed tannins failed to produce synergistic effects on methane mitigation. This work showed that enteric methane production by ruminants could be reduced in tropical areas by the inclusion of hydrolysable tannins without compromising digestive processes in the rumen; methane mitigation with condensed tannins may result in a reduction of the extent of fermentation

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45

Fang, Gang. "Evaluation and performance of a tannin-based polymer as a coagulant in water treatment". Thesis, Imperial College London, 2007. http://hdl.handle.net/10044/1/1280.

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In drinking water treatment, there is growing interest in the application of natural cationic polymers that provide an alternate means to achieve enhanced coagulation. A review of the relevant literature concerning the coagulation mechanisms and action of polymer is presented with particular reference to the polymer character, such as polymer type, charge density and molecular weight. In addition, basic knowledge of a novel coagulant, a tannin-based modified polymer, is described. A full characterization of the tannin-based polymer (TBP) has been undertaken to provide an unambiguous description of the polymer, or monomer, structure. Some specialised newer analytical techniques in combination with several old classical techniques for polymer examination have been used to determine the chemical nature of the TBP, including its dissociation and precipitation behaviour, molecular weight, charge density, charge variability with pH, elemental content, functional group and chemical bonding, etc. The overall assessment of TBP indicated that it can be classified as a medium molecular weight polymer with a non-quaternized amine group and a charge density that varies with pH and time. The fundamental coagulation mechanisms and stoichiometry of suspended solid/dissolved organic matter with TBP have been investigated through laboratory experiments. Suspensions of kaolin clay and humic acid have been flocculated in a Gator jar using TBP as a sole primary coagulant. Using online analysis by Photometric Dispersion Analyzer (PDA), the relative floc size was indicated by a Flocculation Index (FI) during the coagulation process and the optimal concentration of coagulants was determined in overall terms by NPDOC, turbidity, colour, UV/Vis absorbance and Floc volume. Under given conditions the optimum dose of TBP corresponded to that required for maximum a 3 Flocculation Index (FI). The optimum dose of TBP was found to depend on the charge density of TBP and hence on the pH values of the solution. At neutral and acid condition, quantitative evidence of a stoichiometric relationship between TBP dosages with the concentrations of model impurity was illustrated. Complicating effects were present at higher pH values. The coagulation behaviour of TBP was generally in agreement with the coagulation mechanisms widely observed, and typical, of cationic polymers. It was evident that the coagulation performance and kinetics of TBP was also influenced by other factors, such as the velocity gradient, ageing of polyelectrolyte and reactor design. For comparative purposes, alum and a commonly used synthetic cationic polymer (polyDADMAC) were also assessed in this study as coagulants. The potential benefits to improving coagulation performance through the combination of TBP with alum as a dual primary coagulant have been investigated. Coagulation experiments using different model waters were carried out under conditions designed to optimize the maximization of flocculation. A full matrix of coagulation tests demonstrated that a unique optimal dosage of combined alum and cationic TBP exists at a given pH and component concentration. In this case, a significant reduction of alum with an improvement of coagulation efficiency was achieved. An approach to minimize the residual soluble TBP in treated waters and increase the floc settling by attaching the TBP to an inert solid (fine sand) has been attempted. The coagulation performance using this particle suspension (‘solid bound TBP’) as coagulant was found to be inferior with a high shear rate in accordance with the floc strength interpretations of TBP. Additional tests with raw waters were carried out to confirm the validity of the findings from the model water experiments using TBP and the alum/TBP combinations as primary coagulants. In the light of these studies, the relative importance of TBP’s chemical properties, especially molecular weight, charge density and solubility, as crucial 4 parameters of coagulation mechanism is discussed. Furthermore, approaches to improve flocculation performance with either partial replacement of inorganic coagulant or the combination with microsand are suggested and analysed.

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Juhnke, Jessica A. "Effects of Tannin-Containing Feed on Haemonchous contortus in Sheep and Its Behavioral Implications". DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1058.

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Herbivores prefer foods that supply required nutrients and avoid those with excess nutrients and plant secondary compounds (PSC). Nevertheless, PSC such as condensed tannins can provide beneficial medicinal effects to herbivores. The objectives of this study were to determine: 1) if parasitized lambs increased preference for a tannin-rich food after they experienced the beneficial antiparasitic effects of tannins relative to parasitized lambs that did not experience such benefits, 2) if preference for the tannin-containing food in the former group decreased when parasite burdens subsided, and 3) if the tannin-enriched food decreased parasitic burdens. Twenty-two lambs were familiarized with beet pulp and beet pulp + 8% quebracho tannins and choices were given between the two foods (initial preference tests). Subsequently, all animals were dosed with 10,000 L3 stage larvae of Haemonchous contortus. Twenty-two days later, animals were exposed to beet pulp (Control group; n=11) or beet pulp+tannins (Treatment group; n=11) during a span of 24 d. After exposure (during a parasitic infection) animals in both groups were given choices between the two foods. Lastly, animals in both groups received an antiparasitic drench and were again given a choice between both foods (after a parasitic infection). Lambs preferred beet pulp to beet pulp + tannins throughout the study (P< 0.001) and no difference in preference for the tannin-rich food was detected between groups during initial preference tests (P > 0.05). However, during a parasitic infection, intake of and preference for the tannin-containing food was higher for Treatment lambs than for Control lambs (P < 0.05). When parasitic infections were terminated by chemotherapy, differences between groups disappeared (P > 0.05). Preference by the Treatment group for the tannin-containing food was lower after than during a parasite infection (P < 0.05). In contrast, preference by the Control group did not change during these periods (P > 0.05). Lambs in the Treatment group displayed lower FEC than lambs in the Control group (Group x Sampling Date; P < 0.05). These results show lambs needed to learn about the beneficial antiparasitic effects of tannins (Treatment) to increase their preference for the tannin-containing food.

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Junior, Flavio Perna. "Efeito de aditivos alimentares sobre a produção de metano ruminal utilizando a técnica de fermentação ruminal ex situ (micro-rúmen), digestibilidade aparente total e excreção de nutrientes em bovinos". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-21032014-114008/.

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Problemática mundial levantada nas últimas duas décadas, a geração de gases de efeito estufa (GEE) tem parte devida à emissão de metano por ruminantes. O metano, um potente GEE, é produto final do processo fermentativo de bovinos e, por constituir perda no potencial produtivo destes, tem sido objeto de estudo por nutricionistas do mundo todo. Na busca por estratégias para diminuírem essas perdas, diferentes dietas, aditivos e manejos nutricionais têm sido empregados. Portanto, o objetivo deste trabalho foi avaliar o efeito dos aditivos alimentares, monensina ou tanino, sobre a produção de metano ruminal em bovinos, utilizando-se a técnica de fermentação ruminal ex situ (micro-rúmen), e sobre os parâmetros da fermentação ruminal, a digestibilidade aparente total e a excreção de nutrientes da dieta. Seis vacas (873 ± 81 kg) canuladas no rúmen foram utilizadas e distribuídas a três dietas, que diferiram quanto ao aditivo utilizado, seguindo-se delineamento experimental em quadrado latino 3x3 replicado (n= 18 unidades experimentais): Controle (CON): sem aditivo; Monensina (MON): adição de 300 mg de monensina sódica por animal por dia; Tanino (TAN): adição de 100 g de extrato concentrado de tanino condensado obtido da Acácia-negra (Acacia mearnsii) por animal por dia. Cada período experimental foi constituído de 21 dias, sendo que, entre o dia 5 e o dia 15, 2 g do marcador óxido crômico por kg de MS de alimento consumido foi administrado via cânula ruminal, para determinação da digestibilidade aparente total da MS e suas frações, bem como da excreção dos nutrientes da dieta. O ensaio de digestibilidade foi constituído por duas fases, sendo os cinco primeiros dias para adaptação ao marcador e os cinco últimos para coleta de fezes. A excreção da MS e dos nutrientes, bem como a excreção de nitrogênio, foi calculada a partir dos dados de coeficiente de digestibilidade da MS e suas frações. Para cada período experimental, os últimos 6 dias foram destinados para coleta de dados do consumo de matéria seca (CMS). No dia 21 coletou-se líquido ruminal, antes, 3, 6, 9 e 12 h após a alimentação matinal, para determinação da concentração de ácidos graxos de cadeia curta (AGCC) e metano (CH4). As concentrações de CH4 e AGCC foram determinadas por cromatografia gasosa. O pH ruminal foi mensurado por um dispositivo contínuo de mensuração, durante 24 horas no 21º dia de cada período experimental. A técnica de fermentação ex situ consiste em incubar frascos tipo penicilina com conteúdo ruminal sólido e líquido, em banho termostático por 30 minutos, com posterior mensuração da produção de metano por cromatografia gasosa, sendo estimada a perda de energia relativa (PER). A PER avalia a eficiência da fermentação dos alimentos, ou seja, verifica a perda de metano quando comparada aos outros produtos da fermentação, tais como, acído acético, propiônico e butírico. Os dados foram analisados pelo programa SAS (Versão 9.2, 2010) através do procedimento MIXED. No modelo, o efeito de tratamento foi considerado fixo e os efeitos de período, quadrado e animal dentro de quadrado considerados aleatórios. Não houve diferenças significativas (P0,05) entre os tratamentos para o consumo, digestibilidade aparente total e excreção da MS, PB, EB, FDN, FDA, EE, ENN, MO ou P, nem na digestibilidade do NDT e na excreção de N. Não houve efeito signifivativo dos aditivos (P>0,05) sobre a concentração de N-NH3, pH ruminal, para os ácidos acético, propiônico e butírico, nem para o AGCC total. Para a variável metano houve diferença significativa (P<0,05), sendo que o tratamento com monensina foi responsável por reduzir a produção de metano em 10,7%, já o tanino reduziu em 8,0%, quando comparados ao tratamento controle. Observou-se que a PER foi diminuída significativamente em 20,3% e 23,8% (P=0,0387) com a administração dos aditivos monensina e tanino, quando comparadas ao tratamento controle. Portanto, a utilização de monensina ou tanino, em dietas com proporção de volumoso e concentrado de 50%, demonstra ser uma interessante opção em dietas para bovinos, com vistas a eficiência energética dos animais, não interferindo sobre o consumo, digestibilidade e excreção dos nutrientes com consequente redução nas emissões de metano.
Worldwide problem raised in the last two decades, the generation of greenhouse gases (GHG) is partly due to methane emission by ruminants. Methane, a powerful greenhouse gas, is the end product of the fermentation process in cattle, and as is considered a potential loss in their productive potential has been studied by nutritionists worldwide. In the search for strategies to decrease these losses, different diets, additives and nutritional management have been employed. Therefore, the aim of this study was to evaluate the effect of feed additives monensin or tannins on ruminal methane production in cattle evaluated by the technique of ex situ ruminal fermentation (micro-rumen), and on rumen fermentation parameters, as well as, total tract apparent digestibility and excretion of nutrients. Six ruminally cannulated cows (873 ± 81 kg) were distributed to three diets that differed on the additive used, in a replicated 3x3 Latin square experimental design (n=18 experimental units): Control (CON): no additive; Monensin (MON) addition of 300 mg of monensin per animal per day; Tannin (TAN): addition of 100 g of concentrated extract condensed tannin obtained from black wattle (Acacia mearnsii) per animal per day. Each experimental period consisted of 21 days, and between day 5 and day 15, 2 g per kg DM consumed of the marker chromic oxide was administered via rumen cannula for determination of DM and its fractions apparent digestibility as well as, excretion of nutrients. Digestibility trial consisted of two phases, the first five days for adaptation to the marker and the last five for feces sampling. The excretion of DM and nutrients, as well as, nitrogen excretion was calculated from the data of DM digestibility and its fractions. In each trial, the last 6 days were used for data collection of dry matter intake (DMI). On day 21, ruminal fluid was collected before, 3, 6, 9 and 12 h after morning feeding to determine the concentration of short chain fatty acids (SCFA) and methane (CH4). The concentration of SCFA and CH4 were determined by gas chromatography. Rumen pH was measured by a continuous measurement device for 24 hours on day 21 of each experimental period. The fermentation technique consists of ex situ incubation of penicillin flasks with liquid and solid rumen contents in water bath for 30 minutes, with subsequent measurement of methane production by gas chromatography, with final estimation of relative energy loss (REL). The REL evaluates the efficiency of feed fermentation , in other words, verifies methane loss when compared to the other fermentation products such as acetic, propionic and butyric acids. Data were analyzed using the MIXED procedure of SAS (Version 9.2, 2010). In the model, the effect of treatment was considered fixed and the effects of period, square, and animal within square were considered random. No significant differences (P0.05) between treatments were observed for dry matter intake, apparent digestibility and excretion of DM, CP, GE, NDF, ADF, EE, NFE, MO or P, nor TDN digestibility and N excretion. There was no significant effect (P>0.05) of additives on rumen pH, concentration of total SCFA, acetic, propionic and butyric acids, as well as, NH3- N. Monensin reduced (P<0.05) methane production by 10.7%, whereas tannin reduced by 8.0%, when compared to control treatment. Relative energy loss was significantly decreased by 20.3% and 23.8% (P=0.0387) with administration of monensin and tannin when compared to control. Therefore, the use of monensin or tannin in diets with forage to concentrate ratio of 50%, shows to be an interesting option in catlle diets aiming to improve energy efficiency in animals, not interfering on intake, digestibility and nutrient excretion with consequent reduction in methane emissions.

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Gaffney, Simon Henry. "An investigation into the interaction of phenols and polyphenols with proteins and polysaccharides". Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278431.

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Chupin, Lucie. "Etude de l’extraction de tanins d’écorce de pin maritime pour l’élaboration de colles tanin-lignosulfonate". Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3023/document.

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Abstract (sommario):

Cette étude a deux objectifs principaux : l’extraction de tanins condensés d’écorces de pin maritime et la formulation de colles tanin-lignosulfonate. Deux méthodes d’extraction ont été étudiées. La première est une extraction à l’eau chaude ; c’est une technique simple, peu coûteuse, sans solvant. La deuxième est une extraction assistée par micro-ondes ; c’est une technique innovante, rapide et peu consommatrice en solvant. L’optimisation des conditions d’extraction à l’eau chaude a été réalisée. Les extraits ont été caractérisés par des dosages colorimétriques, leur réactivité au formaldéhyde, par infrarouge à transformée de Fourier (IRTF), par chromatographie en phase liquide à haute pression, par 1H RMN et 2D HSQC RMN. L’impact de la granulométrie sur l’extraction de polyphénols et particulièrement de tanins condensés par extraction assistée par micro-ondes a été étudié pour la première fois. Les deux types d’extraction ont été comparés. L’extraction assistée par micro-ondes a un rendement en extractibles inférieur à l’extraction à l’eau chaude. Mais elle extrait plus de tanins condensés, de flavonoïdes simples et plus de sucres. Quelle que soit la méthode d’extraction, les tanins condensés majoriatires extraits de l’écorce de pin maritime sont de la catéchine, de l’épicatéchine, de l’épicatéchine gallate et de l’épigallocatéchine. Des colles tanin-lignosulfonate ont été produites en utilisant l’héxaméthylènetetramine comme durcisseur. Dans un premier temps, des tanins de mimosa ont été utilisés avec des lignosulfonates de sodium et des lignosulfonates d’ammonium. Les lignosulfonates ont subi deux traitements au glyoxal qui ont été comparés par analyse thermogravimétrique (ATG), par calorimétrie différentielle à balayage (DSC), par les propriétés thermiques et mécaniques de colles et de panneaux de particules avec des lignosulfonates ayant subi les deux traitements ont également été étudiées. L’optimisation du ratio tanin de mimosa-lignosulfonate glyoxalé a été menée et les propriétés thermiques des colles mesurées. L’optimisation des conditions de pressage de panneaux de particules a été réalisée. Des panneaux de particules avec de bonnes performances mécaniques ont été fabriqués. Des colles à base de tanins d’écorce de pin maritime et de lignosulfonates ont été réalisées avec 40% de tanins et 60% de lignosulfonates. Ces colles ont été caractérisées par IRTF, analyse thermomécanique, ATG et DSC. Ces colles sont rentrées dans la fabrication de panneaux de particules. Les émissions de formaldéhyde et la cohésion interne des panneaux ont été mesurées et comparées à des panneaux encollés avec une colle tanin de mimosa-lignosulfonate et une résine urée-formaldéhyde. Grâce à ces résultats, il a été possible de montrer que les panneaux de particules fabriqués à partir de colles bio-sourcées n’émettaient pas de formaldéhyde
This study has two main objectives: the extraction of condensed tannins from maritime pine bark and the preparation of tannin-lignosulfonate adhesives. Two extraction methods were studied. The first is hot water extraction which is a simple, cheap method without the use of an organic solvent. The second is microwave-assisted extraction which is a fast, innovative method using only a small amount of solvent. Optimum extraction conditions were determined for hot water extraction. The extracts were characterised by their reaction to formaldehyde and by using colorimetric tests, Fourier Transformed Infrared spectroscopy (FTIR), high pressure liquid chromatography, 1H NMR and heteronuclear single quantum correlation 2D NMR.. The two types of extraction were compared. It was found that microwave-assisted extraction produced a lower yield of extractibles than the hot water method but that it produced more condensed tannins, simple flavonoids and sugars. The condensed tannins extracted from maritime pine bark are catechin, epicatechin, epicatechin gallate and epigallocatechin, whatever the extraction method used. Tannin-lignosulfonate adhesives were produced using hexamethylenetetramine as a hardener. First, mimosa tannins were used with sodium lignosulfonates and ammonium lignosulfonates. The lignosulfonates underwent two glyoxal treatments which were compared using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and by determining the thermal and mechanical properties of the adhesives and of the particle boards made using the lignosulfonates resulting from the two treatments. The optimum mimosa tannin-glyoxalated lignosulfonate ratio was determined and the thermal properties of the adhesives were measured. The optimum conditions of pressing the particle boards were determined. Particle boards which recorded a good mechanical performance were produced. Adhesives using maritime pine bark tannins and lignosulfonates were prepared with 40% tannins and 60% lignosulfonates. These adhesives were characterised using FTIR, thermomechanical analysis, TGA and DSC. These adhesives were used to produce particle boards. The emission of formaldehyde and the internal bond of the boards were measured and compared to those of boards made with a mimosa tannin-lignosulfonate adhesive and to those of boards made with a urea-formaldehyde resin. Thanks to these results, we were able to produce particleboards with bio-based adhesives that didn’t emit formaldehyde

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Alves, Tiago Pansard. "AVALIAÇÃO DO USO DE EXTRATO TANÍFERO DE Acacia mearnsii COMO MODULADOR DA FERMENTAÇÃO RUMINAL EM BOVINOS". Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/10791.

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Abstract (sommario):

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The effect of levels of Acacia meanrsii tannin extract addition in cattle diet (0, 0.8, 1.6 or 2.4%, dry matter (DM) basis) on rumen fermentation, digestion and N retention was evaluated. The experiment was conducted in a 4 x 4 Latin Square design with four steers (156 ± 33 kg of body weight (BW)) housed in metabolism cages. Diet was 60% oat (Avena strigosa) and 40% concentrate containing soybean meal as the major protein source. Feed was offered in an amount restricted to 2% of BW as such it was not affected by treatments. Tannin extract inclusion did no effect rumen pH whereas decreased (P≤0,10) ruminal concentration of ammonia N, α-amino N and reducing sugars. The apparent and true OM digestibility were not affected by tannin extract. The ruminal OM digestibility decreased linearly (P≤0,10) and duodenal flow of N α-amino linearly increased (P≤0,10) at increased levels of tannin extract inclusion. Inclusion of 4 or 6% of tannin extract decreased urinary N excretion and improved N retention (P≤0,10). In conclusion, inclusion of up to 2.4% of Acacia tannin extract in cattle diet has the potential to increase the supply of metabolizable protein without adversely affecting the energy supply.
Foi avaliado o efeito da adição de níveis de extrato tanífero de Acacia mearnsii na dieta de bovinos sobre variáveis da fermentação ruminal, da digestão e retenção de N. Foram utilizados quatro bovinos da raça Holandês, machos castrados (156±33 kg de peso corporal), implantados cirurgicamente com cânula duodenal e sonda ruminal em um delineamento Quadrado Latino 4×4, com quatro períodos experimentais de quinze dias, sendo dez dias para adaptação às dietas e cinco dias para coleta de amostras. A dieta foi constituída de 60% de aveia preta (Avena Strigosa) fornecida duas vezes ao dia (08:00h e 17:00h), e 40% de concentrado composto de 30% de farelo de soja, 35% farelo de arroz desengordurado e 35% de milho triturado, fornecido três vezes ao dia (8:00h, 12:30h e 17:00h). Foi testada a inclusão de 0, 2, 4 e 6% de extrato tanífero (base de MS) no concentrado. O consumo de MS da dieta foi restrita a 2% do peso vivo dos animais. A inclusão do extrato tanífero reduziu linearmente (P≤0,10) as concentrações ruminais de N-amônia, N α-amino e açúcares redutores, mas não afetou o pH ruminal. A digestibilidade total aparente e verdadeira da matéria orgânica da dieta não foi afetada pelos tratamentos. A retenção de N foi mais alta e a excreção urinária de N foi mais baixa nos tratamentos com 4 e 6 % de inclusão de extrato tanífero no concentrado (P≤0,10). Com o aumento da inclusão de extrato tanífero no concentrado a digestibilidade ruminal da matéria orgânica reduziu linearmente (P≤0,10). Quando expresso em relação a MO consumida, o fluxo duodenal de N α-amino aumentou linearmente (P≤0,10) com o aumento do extrato tanífero A inclusão de extrato tanífero de Acacia mearnsii no concentrado até o nível de 6% da MS (2.4% da dieta), tem o potencial de aumentar a oferta de proteína metabolizável sem afetar negativamente a oferta de energia digestível em bovinos alimentados com dietas que incluem concentrado com alta proporção de proteína degradável no rúmen.

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