Orientador: Alba Regina Monteiro Souza Brito / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias / Made available in DSpace on 2018-08-13T20:43:04Z (GMT). No. of bitstreams: 1 Faria_FelipeMeirade_M.pdf: 4207314 bytes, checksum: 70c7146121839f75d360ebf1de64eb88 (MD5) Previous issue date: 2009 / Resumo: A pesquisa farmacológica têm se voltado ao conhecimento da medicina popular, a fim de estabelecer as bases científicas dos seus efeitos farmacológicos. Atualmente taninos têm papel de destaque em função de sua capacidade antioxidante e em função dos avanços obtidos na análise e identificação desses compostos além de suas possibilidades terapêuticas. Entre as diversas fontes naturais desses compostos destacou-se, neste trabalho, uma planta bastante conhecida nos ambientes costeiros, a Rhizophora mangle L. (manguevermelho), pertencente à família RHIZOPHORACEAE. O gênero Rhizophora compreende cinco espécies das regiões equatorial, tropical e subtropical de ambos os hemisférios. É uma das mais importantes fontes de taninos (15 a 36% da massa da casca seca) para uso industrial. R. mangle é conhecida na medicina popular caribenha por suas propriedades antinflamatória, antifúngica, bactericida, anti-úlcera, antihipertensiva e antioxidante. Este trabalho avaliou as atividades antiulcerogênica e antioxidante de R. mangle, assim como traçou o perfil químico das substâncias presentes em suas cascas. Para tanto foram realizados ensaios químicos e farmacológicos com o extrato bruto (acetona:água 7:3) e frações orgânicas (aquosa - fr aq, acetato de etila - fr-EtOAc e butanólica - fr-BuOH) dele obtidas. A análise da atividade antiulcerogênica do extrato e frações, mostrou que fr-BuOH foi mais eficaz na dose de 0,5mg.Kg-1. Essa fração também apresentou atividade antioxidante significativa. Nos ensaios químicos realizados, tanto para o extrato bruto quanto para as frações, verificou-se a existência de alta concentração de compostos polifenólicos. Os testes farmacológicos com a fr-BuOH buscaram determinar os mecanismos pelos quais são exercidas as atividades antiulcerogênica e antioxidante das substâncias nela presentes. Concluiu-se que fr-BuOH possui catequinas heterosídeos, galotaninos, elagitaninos e taninos complexos em sua composição, de acordo com métodos de análise empregados. Estas substâncias mostraram-se capazes de sequestrar radicais livres, atuar sobre compostos (GSH) e enzimas antioxidantes (GR, GPx e SOD) e próoxidantes (MPO e LPO) definindo sua atividade antioxidante. A atividade antiulcerogênica além de ser mediada pela própria ação antioxidante é dependente de GSH e NO, envolve a participação de PGE2, COX-2, EGF, PCNA, HSP-70, além do aumento da produção de muco aderido e propriedades anti-secretoras / Abstract: The pharmacological research has been focusing on the folk medicine knowledge in order to establish the scientific basis of their pharmacological effects. Nowadays, tannins play a prominent role because of its high antioxidant capacity and, due to the progress made in the analysis and identification of these compounds and their therapeutic possibilities. Among the many natural sources of these compounds, highlighted in this work a well known plant in coastal environments, the Rhizophora mangle L., belonging to the family RHIZOPHORACEAE. The genus includes five species of Rhizophora in equatorial, tropical and subtropical regions in both hemispheres. It is one of the most important sources of tannin (15 to 36% of the dry bark weight) in industrial use. Rhizophora mangle is well known in the Caribbean folk medicine for its anti-inflammatory, antifungal, antibacterial, anti-ulcer, anti-hypertensive and antioxidant properties. This study aimed to evaluate the antioxidant and anti-ulcer activities of R. mangle, and to elucidate the chemical compounds present in its barks. For both evaluations chemical and pharmacological assays with the crude extract (acetone: water 7:3) and their organic fractions (aqueous - fr-aq, ethyl acetate - fr-EtOAc and butanolic - fr-BuOH) were performed. The analysis of anti-ulcer activity of the extract and fractions showed that fr-BuOH was more effective at a dose of 0,5 mg.Kg-1. This fraction also showed significant antioxidant activity. It was found the presence of high concentrations of polyphenolic compounds in the chemical assay performed for both the crude extract and its fractions. The pharmacological experiments were carried out to determine the mechanisms by which the compounds present in fr-BuOH exert their antiulcer and antioxidant activities. It was concluded that the fr-BuOH has antioxidant activity linked to the concentration of polyphenolic compounds, which were able to scavenge free radicals, maintain the levels of GSH, reduce the MPO activity and LPO levels and maintain or increase the antioxidant enzymatic activities of GR, GPx and SOD. Moreover, the antiulcer activity of fr-BuOH is mediated by several mechanisms including: antioxidant action; involvement of GSH and NO; anti-secretory properties; increase of mucus and PGE2 synthesis, and expression of COX-2, EGF, HSP-70 and PCNA on gastric mucosa. Chemical study revealed that the major compounds are heteroside catechins, gallotannins and "tannin complexes" / Mestrado / Mestre em Farmacologia

Orientador: Claudia Regina Baptista Haddad / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T15:33:32Z (GMT). No. of bitstreams: 1 Noleto_LeonardoGoncalves_D.pdf: 8581995 bytes, checksum: 12b214dbb64d8243d691234477807b02 (MD5) Previous issue date: 2010 / Resumo: Árvores e lianas possuem diferentes estratégias de alocação de recursos durante o ciclo fenológico. As lianas são componentes florísticos importantes e parte significativa das espécies de florestas tropicais, mas ainda pouco estudadas no Bioma Cerrado. A duração do ciclo de vida foliar de diferentes espécies reflete sua adaptação ao habitat, bem como as concentrações de certos compostos orgânicos nitrogenados, que influenciados por fatores ambientais estão relacionados com o crescimento vegetativo. Entre os elementos minerais o nitrogênio é um dos mais limitantes em plantas e sua conservação é dependente da sua disponibilidade no ambiente. O reaproveitamento do nitrogênio é mensurado pela eficiência de reaproveitamento do nitrogênio, pela eficiência no uso do nitrogênio e pela proficiência de reaproveitamento de nitrogênio. A baixa disponibilidade do nitrogênio no solo é determinante para sua conservação, mas muitas espécies vegetais conservam esse nutriente apresentando folhas com alta longevidade. Embora as lianas e árvores do presente trabalho ocorram no mesmo ambiente, presume-se que os índices relativos à conservação do nitrogênio sejam menores nas lianas, quando comparados aos das espécies arbóreas, já que alguns autores verificaram que lianas possuem um sistema vascular e radicular mais eficiente que os das árvores, o que pode possibilitar uma aquisição mais eficiente de nutrientes minerais. Além disso, as lianas ocorrem com freqüência em áreas florestais perturbadas, onde árvores são derrubadas, onde há abundância da quantidade de luz e serrapilheira (fonte de N disponível no solo). Compostos fenólicos normalmente são encontrados em maiores concentrações em espécies com folhas longevas. Esses compostos exercem papel de defesa contra herbívoros e patógenos. A concentração desses compostos é influenciada pelo balanço carbono/nutriente nos tecidos vegetais, bem como por fatores climáticos. A hipótese que norteia a presente pesquisa é a existência de diferentes estratégias fisiológicas apresentadas por árvores e lianas no que diz respeito aos índices de conservação do nitrogênio, investimento em estruturas vegetativas (longevidade foliar, massa foliar por área, e diâmetro basal do fuste) e concentrações de compostos fenólicos e nitrogenados. Os objetivos deste trabalho foram: 1- Relacionar os índices de conservação do nitrogênio a aferições biométricas (longevidade foliar, massa foliar por área e diâmetro do fuste à altura de 30 cm) e concentração foliar de compostos fenólicos e nitrogenados nas espécies de árvores e lianas; 2- Verificar se há diferenças entre as árvores e lianas quanto aos aspectos acima mencionados e 3- Investigar o efeito da estacionalidade sobre as concentrações de compostos fenólicos e nitrogenados em folhas desses dois grupos de plantas. O trabalho foi conduzido em duas épocas distintas (seca e chuvosa) em um fragmento de cerrado denso, conhecido como Valério, na Estação Experimental de Itirapina, no estado de São Paulo. O diâmetro basal dos caules das espécies estudadas correlacionou-se negativamente com a massa foliar por área. Comparando-se os diâmetros basais de lianas e árvores verificou-se que as primeiras apresentaram caules mais finos, o que poderia indicar um maior investimento de compostos orgânicos na parte aérea dessas plantas. Apresentaram também uma menor massa foliar por área, provavelmente indicando a existência de sistemas radiculares e de transporte mais eficientes do que nas árvores, ou estratégias diferentes de distribuição de matéria orgânica nos dois grupos funcionais, ou, ainda, maior síntese de compostos estruturais de carbono nas espécies arbóreas, o que explicaria a maior concentração de compostos nitrogenados nas folhas de lianas. As lianas apresentaram o menor desempenho na conservação do nitrogênio. Esse desempenho das lianas pode estar relacionado à maior concentração desse elemento nas folhas maduras dessas plantas. Quando se compara as duas épocas analisadas, verifica-se que os compostos nitrogenados aumentaram na época chuvosa, paralelamente ao aumento de fenóis totais. Como a época chuvosa é também a época mais quente na região estudada, a combinação de maior disponibilidade de água e temperaturas mais altas pode ter propiciado um aumento no sistema de absorção e transporte de nitrato na planta, que se refletiu na maior concentração de aminoácidos. É possível que tenha havido aumento suficiente na concentração de aminoácidos precursores para sustentar os aumentos nas sínteses de proteínas e fenóis nesse período. O aumento da concentração de taninos condensados na época seca pode estar relacionado com efeitos da amplitude térmica diária sobre o metabolismo desses compostos ou com aumento de herbivoria no período seco, resultando na maior produção de taninos pelas plantas / Abstract: Trees and lianas present different strategies for allocating resources during the phonological cycle. Whereas Lianas are important floristic components and account for a significant number of rainforest species, few studies have been conducted in the Cerrado (a savanna like vegetation) biome. The duration of the leaf life span in different species reflects both its adaptation to the habitat, and the concentrations of certain organic nitrogen-containing compounds, which are influenced by environmental factors and are related to vegetative growth. Nitrogen is one of the most limiting mineral elements in plants, and its conservation depends on its availability in the environment. Nitrogen resorption is measured by nitrogen resorption efficiency, nitrogen use efficiency, and by nitrogen resorption proficiency. The low availability of nitrogen in the soil is a determining factor for its conservation, but many plant species preserve this nutrient with leaves that present a long life span. Although the lianas and trees from this research work share the same environment, it is assumed that the parameters related to nitrogen conservation are lower in the lianas when compared to those of the woody species, as some authors have verified that lianas present a more efficient vascular and root system than that of trees, which might provide them with a more efficient absorption of mineral nutrients. Moreover, lianas frequently occur in disturbed forest areas where trees are torn down, and there is an abundance of light and litterfall (a N source available on the soil). Larger concentrations of phenolic compounds are normally found in species whose leaves present a long life span. Such compounds protect these species against herbivores and pathogens. The concentration of these compounds is influenced by the carbon-nitrogen balance in plant tissues, as well as by climatic factors. The hypothesis that guides this research work is the existence of different physiological strategies presented by both trees and lianas regarding nitrogen conservation mechanisms, investment in vegetative structure (leaf life span, leaf life ratio, and basal diameter of the stem), and concentrations of phenolic and nitrogencontaining compounds. This research work aimed at: 1- Relating nitrogen conservation mechanisms to biometric measurements (leaf life span, leaf life ratio, and basal diameter of the stem at 30 cm high), and to the leaf concentration of phenolic and organic nitrogen-containing compounds in tree and liana species; 2- Establish differences between trees and lianas regarding the aforementioned aspects, and; 3- Investigate the effect of seasonal changes on the concentrations of phenolic and organic nitrogen-containing compounds in the leaves of both kinds of plants. This research work was conducted in two different seasons (dry and rainy) in a fraction of a dense cerrado area known as Valério, at the Itirapina Experimental Station, in the state of São Paulo, Brazil. The researched species presented a negative correlation between the basal diameter of the stems and the leaf mass area. Comparison of the basal diameters of both lianas and trees showed that lianas have thinner stems and a lower leaf mass area, indicating a more efficient vascular and root system than that of trees, or different strategies for distribution of organic compounds in both kinds of plants, or a higher synthesis of structural carbon compounds in the tree species, which could explain the greater concentration of nitrogen-containing compounds in liana leaves. Lianas presented lower performance in nitrogen conservation. Such a performance may be related to the greater concentration of nitrogen in mature liana leaves. Comparison of the two analyzed seasons shows that in the rainy season there was an increase in the concentration of nitrogenous compounds, as well as an increase in the contents of phenolic compounds. Since the rainy season is also the hottest in the research area, the combination of larger availability of water and higher temperatures may have caused an increase in the absorption and transportation system of nitrate in the plants, which reflected in a greater concentration of amino acids. There may have been a sufficient increase in the concentration of precursor amino acids to sustain the increase in protein and phenol synthesis during this period. The increase in the concentration of condensed tannins in the dry season may be related to the effects of the daily temperature range on the metabolism of these compounds, or to the increase in herbivory during the dry season / Doutorado / Doutor em Biologia Vegetal

Cationized tannins as a retention aid for cellulose fibre Daniel Bäckström   Abstract The purpose of this study was to try cationized tannins as a potential retention aid for cellulose fibres in papermaking and to compare their potential with starch which already is commonly used. The study also tried to find other advantages with using tannins as a retention aid. Synthetic retention aids like polyacrylamide is also commonly used in papermaking, with good results. Synthetic retention aids are long-lived and their long-term effect on the environment is unkown. Therefore the demands are growing for more bio-degradable products. Measure glass, turbidity removal and COD was used in this study to analyse tannins as a retention aid on cellulose fibres. The results showed very clear water and a higher flocculation compared to the glass without tannins. 500 ppm tannins added to recycled fibres showed the best results for both flocculation and clear water as well as the highest turbidity removal, from 85 to 24 FTU. Different tannins was used in this study, and Tanfloc from the bark of the Acacia tree showed the best results. In the comparison between cationized starch and Tanfloc, Tanfloc showed better results for both flocculation and clearer water. Tannins shows potential as a retention aid for cellulose fibres, but clearer water and higher flocculation is not enough to determine tannins as a retention aid. They also show potential to solve the problem with bacteria in paper making because of their antibacterial effect. However, more tests and other methods needs to be done to show tannins potential as a retention aid.

Studies undertaken to investigate the binding of low molecular mass analogues of polyphenolic vegetable tannins to collagen have prompted the development of a new method to investigate protein-ligand interactions. This method, the continuous-flow dynamic dialysis method (CFDD), differs from conventional dialysis procedures used for protein-ligand binding studies. In this method, the ligand concentration in the diffusate is monitored automatically at successive closely spaced time intervals while being continuously eluted from the dialysis cell. The primary data obtained by this method consists of a series of spectrophotometric absorbance measurements representing the ligand concentration in the sink compartment of a dialysis cell. This primary data is recorded by means of a data logging device onto a punched paper tape for subsequent computer processing. Two original methods are presented for analysing the primary data to extract the protein-ligand binding isotherm. The first of these is a direct analysis which relies on Fick's first law of diffusion. In this method it is necessary to establish, by means of a control experiment, a value for the ligand permeation constant. This is used in a subsequent analysis to establish a relationship between the measured rate of diffusion of the ligand from a protein-ligand mixture and the concentration of unbound ligand which is in equilibrium with the protein-ligand complex. The protein-ligand binding isotherm is obtained from parametric equations which give the quantity of ligand bound to the protein and the concentration of unbound ligand in the sample compartment as functions of time. The second method, which is more general, utilizes the same primary data but is based on establishing a system transfer function to characterise the dialysis and eluting processes. This analysis depends on the linearity of the system and utilizes numerical laplace transforms of the primary data sets obtained from control and protein-ligand dialyses. Laplace transforms are used to effect a deconvolution of the transfer function from the primary data and yield the concentration of ligand in equilibrium with the protein-ligand complex. This procedure yields, simultaneously, both the total ligand concentration and the concentration of unbound ligand in the protein compartment of the dialysis cell. These quantities are used to establish the binding isotherm for the protein ligand system. Numerical inversion of the laplace transforms in this analysis is effected by their reduction to Fourier series. The experimental reliability of the continuous-flow dynamic dialysis method, and validity of the two analytical methods used to derive a binding isotherm from dialysis data are evaluated from studies of the binding of phenol red to bovine serum albumin (BSA) at 15⁰, 20⁰ and 25⁰ C, as well as from simulated binding curves generated by the numerical solution of the differential equations used to describe the dialysis and elution process in terms of a two-site Scatchard binding model. The method is used to investigate the binding to collagen of a series of low molecular mass phenolic compounds which can be isolated from Wattle and Quebracho vegetable tannin extracts. These compounds can be considered as monomeric precursor analogues of the polymeric vegetable tannins. The binding of these ligands to collagen is shown to be characterised by high capacity, low affinity binding in which the uptake of ligand by the protein increases linearly with increasing ligand concentration. Collagen exhibits no indication of site saturation for these ligands over the experimentally accessible concentration ranges investigated.

From Summary: The structural elucidation of condensed tannins, which are considered to consist of C₁₅-flavan units, presents certain difficulties. These tannins occur in extremely complex mixtures, and their isolation is complicated by their susceptibility to oxidative denaturation. Limitations in the formation of significant degradation products add to these problems. Since condensed tannins of black wattle bark yield anthocyanidins on treatment with mineral acids, they are considered to be proanthocyanidin in character. For this reason the initial approach to the investigation of the structures of condensed tannins was by way of the synthesis of novel 7-hydroxyflavan-3,4-diols having a low degree of hydroxyl substitution. Submission of these to modern physical techniques such as nuclear magnetic resonance (n.m.r.) spectroscopy would yield valuable data regarding the chemical shifts and coupling constants of heterocyclic and benzenoid protons which may be used for subsequent work on more highly hydroxylated diols, biflavanols and finally the condensed tannins themselves.

Les tannins sont des produits issus de la chimie végétale qui possèdent une bonne réactivité et qui peuvent remplacer des produits similaires dérivés du pétrole. C’est le cas des tannins condensés qui présentent des caractéristiques de réactivité proches de celles du phénol. Utilisées depuis plusieurs années dans des colles pour les produits à base de bois, les résines de tannin n’ont pas fait l’objet de recherches approfondies pour la fabrication de matériaux composites. Le travail présenté ici est axé sur trois projets visant à développer des matériaux composites de hautes performances en utilisant à la fois des résines à base de tannins condensés et des renforts de fibres végétales. 1. Le premier projet a pour but de développer un composite thermodurcissable à base de la résine tannin/hexamine déjà employée comme colle pour panneaux de particules. Une étude avait démontré la faisabilité du principe mais de nombreux problèmes pratiques restaient à résoudre pour obtenir un processus de fabrication fiable et compétitif. 2. Le but du deuxième projet est l’étude et le développement de composites dont la matrice est constituée d’un copolymère de tannins et d’alcool furfurylique. Les propriétés des résines furaniques et la possibilité de les faire réagir avec des composés phénoliques en font des candidates potentielles à la fabrication de composites de haute performances. 3. Le dernier projet vise à produire des tannins acétylés en suivant les méthodes utilisées pour la lignine, à vérifier s’ils présentent le même caractère thermoplastique et le cas échéant à les tester pour la fabrication de matériaux composites. / Tannins are plant chemicals that show a good reactivity and so they can replace similar products from oil chemistry. This is the case for condensed tannins that have reactivity mechanism similar to that of the phenol. They have been used for several years in wood glues, but no in depth study have been carried out on their potential in composite manufacturing. The work presented here can be split into three projects aiming at the development of composite materials of high performances using both tannin based resins and natural fibers reinforcement. 1. The first project aims to develop a thermosetting composite based on the same tannin/hexamine resin already as glue for particleboards. A previous study shown that it was feasible but numerous problems needed to be solved in order to obtain a reliable and competitive manufacturing process. 2. The goal of the second project is the study and the development of composites which matrix is based on a copolymer of tannin and furfuryl alcohol. Furanic resins show good properties and their capability to react with phenolic compounds makes them potential candidates for the manufacturing of high performances composites. 3. The last project’s objective is the production of acetylated tannins by using similar methods than that used for lignin, to check if they present the same thermoplastic behavior and if yes, to test them in composite manufacturing.

Orientador: Gabriela Alves Macedo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-14T10:38:34Z (GMT). No. of bitstreams: 1 Schons_PatriciaFernanda.pdf: 1271406 bytes, checksum: 668e62b416afd72ff47587e7425cecd0 (MD5) Previous issue date: 2009 / Resumo: Este trabalho visou avaliar o efeito do fungo Paecilomyces variotti e das enzimas fitase e tanase sobre fatores antinutricionais, taninos e fitatos presentes no sorgo tipo vassoura. A enzima tanase produzida pelo fungo Paecilomyces variotti apresentou atividade enzimática de 626U/g, além desta enzima, estavam presentes no extrato enzimático, com menor atividade protease, carboximetilcelulase, polimetilgalacturonase e fitase. A fitase empregada foi comercial (NATUPHOS ¿ BASF) e apresentou atividade de 660U/g. O sorgo utilizado neste estudo possui 13,6% de proteína, 4,2% de lipídeos, 1,7% de cinzas e 80,5% de carboidratos, elevada concentração de compostos fenólicos, especialmente taninos condensados e 226mg/100g de sorgo de fósforo inorgânico. O sorgo foi preparado e tratado com Paecilomyces variotti, tanase e fitase em diferentes combinações. As respostas diminuição de tanino e aumento de fósforo foram avaliados, os melhores resultados foram obtidos quando a farinha de sorgo foi tratada com tanase e fitase durante 5 dias. Por meio de planejamento experimental foi feito estudo do tratamento de sorgo com as enzimas fitase e tanase, o qual indicou a relação entre sorgo:água, como sendo a variável mais significativa para o processo. O processamento (maceração e fervura) e adição das enzimas foram efetivos na redução de taninos e aumento de fósforo, quando comparamos estes resultados com o sorgo cru, porém, as diferentes concentrações das enzimas não tiveram efeito sobre os parâmetros avaliados. Baseado nos resultados expostos, o sorgo para a elaboração das dietas foi tratado com a concentração inferior de enzimas estudada (100U/Kg). O estudo in vivo mostrou que a dieta elaborada com sorgo tratado enzimaticamente foi efetivo na melhoria da digestibilidade aparente de fósforo, na diminuição da excreção de fósforo, resultaram em melhores índice bioquímico para glicose e colesterol, apresentaram uma menor atividade de enzimas hepáticas aspartato aminotrasnferase (AST) e alanina aminotransferase (ALT), comparando com sorgo cru. No entanto, não teve efeito significativo na melhoria do ganho de peso, da digestibilidade aparente de proteína, na concentração de fósforo, ferro e cálcio plasmático, bem como na concentração de mineral contido no fêmur / Abstract: This work aimed assess the fungus Paecilomyces variotti and enzymes phytase, tannase effects on the antinutritional factors, tannins and phytates present in sorghum. The tannase produced by the fungus Paecilomyces variotti has enzymatic activity of 626U/g, in addition this enzyme were present in the enzymatic extract protease, in less activity protease, carboxymetilcellulase, polymetilgalacturonase and phytase. The phytase used is commercially (NATUPHOS ¿ BASF) and has activity of 660U/g. The sorghum utilized in this study has 13.6% protein, 4.2% of lipids, 1.7% ash and 80.5% carbohydrate, high concentration of phenolic, mainly condensed tannins and inorganic phosphorus 226mg/100g sorghum. The sorghum was prepared and treated by using Paecilomyces variotti, tannase and phytase in different combinations. The decrease in the tannins and increase in the phosphorus were evaluated, the best results were obtained when sorghum flour was treated with tannase and phytase for 5 days. Through experimental design were made a study about sorghum treated by the enzymes tannase and phytase, which indicated the relationship between sorghum:water, as the most significant variable in the process. The processing (soaking and boiling) and addition of enzymes were effective in reducing tannin and increase phosphorus, when comparing these results with the raw sorghum, however, different concentrations of the enzymes had no effect on the parameters evaluated. Based on the results above, the sorghum for the preparation of the diets were treated with lower concentration of enzymes studied (100U/Kg). The in vivo assay showed that the diet prepared using sorghum treated enzimaticaly was effective in improving digestibility of phosphorus, reducing the phosphorus excretion, resulting in better biochemical index for glucose and cholesterol, showed a lower activity of liver enzymes aspartate aminotransferase (AST) and alanin aminotransferase (ALT), compared with raw sorghum. However, it had no significant effects in improve weight, the apparent digestibility of protein, and the concentration of phosphorus, iron and calcium in the plasma and mineral content in the femur / Universidade Estadual de Campi / Ciência de Alimentos / Mestre em Ciência de Alimentos

As interações superficiais dominam as propriedades de suspensões de partículas coloidais. O equilíbrio entre a superfície, o solvente e as espécies ativas em solução determina as propriedades relacionadas à reatividade e às interações na interface sólido-líquido. O tanino é um composto extraído da casca de acácia e que pode ser utilizado como estabilizante e dispersante em suspensões cerâmicas coloidais de alumina. O controle das propriedades superficiais da alumina e dos mecanismos que governam sua interação com o tanino é fundamental para ajustar seus efeitos no processamento coloidal. Torna-se necessário garantir uma superfície isenta de contaminantes para avaliar o efeito e a contribuição de cada um dos materiais em suspensão. Neste trabalho foi investigada a adsorção de tanino hidrolisável (TH), condensado (TC) e sulfonado (TS) em partículas de α-Al2O3 dialisadas. A correlação entre os resultados obtidos na caracterização da α-Al2O3 indica que coexistem sítios superficiais AlVI-μ¹-OH, AlVI-μ²-OH e AlVI-μ³-OH; adicionalmente, um sítio AlIV-μ¹-OH deve ser considerado. O estado de protonação de cada sítio é controlado pelas condições do meio, essencialmente pelo pH, revelando que a superfície das partículas de α-Al2O3 é heterogênea. A contribuição dos taninos em suspensão foi definida principalmente pelo pH do meio, uma vez que esta propriedade define o estado de protonação dos grupos polares nas moléculas. A adsorção máxima de TH e TC em α-Al2O3 (9,72 m²/g) foi 12,47 e 14,60 mg/g, respectivamente. O TS adquire uma elevada carga elétrica negativa, o que limita a quantidade adsorvida a 7,34 mg/g, principalmente devido à barreira eletrostática que é formada pela sua adsorção. Essa barreira eletrostática proporciona estabilidade de até -65 mV às suspensões quando a superfície está completamente recoberta, conferindo dispersão robusta às partículas (dH=300 nm), a qual não é afetada pelo aumento da força iônica do meio. A estabilidade inicial das suspensões de α-Al2O3 (+60 mV) foi reduzida progressivamente tanto com o aumento da adsorção de TH e TC quanto da força iônica do meio; para suspensões com potencial zeta entre -25 mV e +25 mV, aglomerados de 400 a 700 nm foram formados. A adsorção de TH, TC e TS ocorre predominantemente por ligações de hidrogênio entre os grupos fenólicos nos taninos e os sítios AlVI-μ²-OH na α-Al2O3, i.e., por adsorção específica. Para condições onde o TS recobre parcialmente a superfície da α-Al2O3, é sugerido que a adsorção ocorra por interações eletrostáticas entre os grupos SO3H e os sítios positivos da α-Al2O3, i.e., por adsorção não específica. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES / Surfaces interactions dominate the properties of colloidal particles suspension. The balance between surface, solvent, and active species in solution determines the properties related to the solid-liquid interface interactions and reactivity. Tannin is a natural compound extracted from acacia bark, which can be used as a stabilizing and dispersing agent in alumina colloidal ceramic suspensions. The control of alumina surface properties and the mechanisms that rules its interactions with alumina is fundamental to adjust its effects on colloidal processing. It becomes necessary to ensure a contaminant-free surface to evaluate the contribution and effect of each suspended species. In this work, it has been investigated the adsorption of hydrolysable (TH), condensed (TC) and sulfonated (TS) tannins on dialyzed α-Al2O3 particles (AD). The correlation between the obtained results for the characterization of α-Al2O3 indicates that surface sites like AlVI-μ¹-OH, AlVI-μ²-OH and AlVI-μ³-OH coexists, and in addition, an extra AlIV-μ¹-OH site must be taken into account. The degree of protonation of such sites is controlled by the conditions of the medium, essentially by pH, displaying that the α-Al2O3 particles surface is heterogeneous. The net contribution of the suspended tannins was mainly defined by the pH of the medium, since this solvent property also defined the state of protonation and deprotonation of the polar groups in the molecules. The maximum adsorption of TH and TC on α-Al2O3 (9.72 m²/g) was 12.47 and 14.60 mg/g, respectively. The TS acquires a high negative electric charge and this, in turn, limits the adsorbed amount to 7.34 mg/g, mainly due to the electrical barrier that is formed by its adsorption. This electrostatic barrier provides stability of up to -65 mV to the suspensions when the surface is fully covered, imparting robust dispersion to the particles (dH=300 nm), which is not affected by the increase in the ionic strength of the medium. The initial stability of the α-Al2O3 suspensions (+60 mV) was progressively reduced both with increasing adsorption of TH and TC as well as ionic strength of the medium; for suspensions with zeta potential between -25 mV and +25 mV, agglomerates from 400 to 700 nm are formed. The adsorption of TH, TC and TS takes place mainly by hydrogen bond between tannin’s phenolic groups and AlVI-μ²-OH on α-Al2O3 by specific adsorption. Under conditions in which the TS partially covers the α-Al2O3 surface, it is suggested that the adsorption takes place only by electrostatic interactions between SO3H groups and positive sites on α-Al2O3, i.e. by non-specific adsorption.

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.

Cattle are responsible for greenhouse gas emissions such as carbon dioxide, methane and nitrous oxide. In particular, the cow-calf phase of production accounts for approximately 80 percent of the total beef production system greenhouse gas emissions. Tannins are chemical compounds found in certain forages and they have the potential to help reduce these negative environmental impacts. Thus, given that the cow-calf phase often relies on feeding hay, feeding tannin-containing hays may represent a significant mitigation practice. With my MS program, I sought to explore whether tannin-containing hays fed to mother cows and heifers influence methane and nitrogen emissions relative to feeding traditional legume and grass hays . I found that “non-traditional” hays such as cicer milkvetch and tannin-containing hays such as sainfoin, birdsfoot trefoil and small burnet can help mitigate greenhouse gas and nitrogen emissions produced from heifers and mature cows. Therefore, these hays could be used to feed cattle during the fall and winter to help create a more environmentally friendly cow-calf phase of beef production.