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Anthocyanins and tannins in ozone-fumigated guava trees

REZENDE, Fernanda Mendes de; FURLAN, Claudia Maria
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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37.36%
Psidium guajava ""Paluma"", a tropical tree species, is known to be an efficient ozone indicator in tropical countries. When exposed to ozone, this species displays a characteristic leaf injury identified by inter-veinal red stippling on adaxial leaf surfaces. Following 30 days of three ozone treatments consisting of carbon filtered air (CF - AOT40 = 17 ppb h), ambient non-filtered air (NF - AOT40 = 542 ppb h) and ambient non-filtered air + 40 ppb ozone (NF + O(3) - AOT40 - 7802 ppb h), the amounts of residual anthocyanins and tannins present in 10 P. guajava (""Paluma"") saplings were quantified. Higher amounts of anthocyanins were found in the NF + O(3) treatment (1.6%) when compared to the CF (0.97%) and NF (1.30%) (p < 0.05), and of total tannins in the NF + O(3) treatment (0.16%) compared to the CIF (0.14%). Condensed tannins showed the same tendency as enhanced amounts. Regression analyses using amounts of tannins and anthocyanins, AOT40 and the leaf injury index (LII), showed a correlation between the leaf injury index and quantities of anthocyanins and total tannins. These results are in accordance with the association between the incidence of red-stippled leaves and ozone polluted environments. (C) 2009 Elsevier Ltd. All rights reserved.; FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[99/06971-9]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Does Propolis Contain Tannins?

Mayworm, Marco Aurélio Sivero; Lima, Carolina A.; Tomba, Augusto César de Barros; Silva, Caroline Cristina Fernandes da; Salatino, Maria Luiza Faria; Salatino, Antonio
Fonte: Hindawi Publishing Corporation; New York Publicador: Hindawi Publishing Corporation; New York
Tipo: Artigo de Revista Científica
ENG
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Although polyphenols have been reported as common constituents of propolis, tannins have rarely been mentioned as its constituents. Propolis samples from seven localities in Brazil were analyzed for detection of proanthocyanidins (condensed tannins) and determination of the tannin content. Positive reaction for proanthocyanidins was observed for all samples tested. The contents of tannins varied in the range 0.6% - 4.1%. A high degree of correlation was noted between total phenols and tannin content. Red and green propolis contained high contents of tannins, while in brown propolis the content was lower. It is suggested that the contents of tannins should be a parameter to be considered in propolis characterization.

"Efeito anti-helmíntico de taninos condensados sobre nematódeos gastrintestinais em ovinos"; Anthelmintic effect of condensed tannins on gastrointestinal nematodes in sheep

Minho, Alessandro Pelegrine
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/02/2006 PT
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As helmintoses gastrintestinais estão entre as principais enfermidades na criação de ovinos, sendo importante causa de mortalidade e de redução na produtividade dos animais. O controle das infecções por nematódeos é baseado no uso de drogas anti-helmínticas, porém com a descrição emergente de parasitos resistentes, a eficácia deste tratamento tem diminuído. Portanto, métodos alternativos de controle são necessários para a diminuição ou, até mesmo, a substituição do uso de drogas para o controle das verminoses em pequenos ruminantes. O uso dos taninos condensados (TC) no controle das helmintoses gastrintestinais de ovinos em todo o mundo tem se mostrado promissor. Este trabalho teve como objetivo avaliar o efeito anti-helmíntico dos TC sobre nematódeos gastrintestinais de ovinos. Durante o período de testes foram realizados quatro ensaios experimentais: ensaio A avaliação in vitro da ingestão por larvas de primeiro estágio (L1) de Haemonchus contortus, Trichostrongylus colubriformis e Teladorsagia circumcincta, para avaliar o efeito anti-helmíntico dos TC provenientes do extrato de acácia (Acacia mearnsii); ensaio B estudo sobre a infecção natural dos cordeiros a campo, animais infectados com H. contortus e T. colubriformis...

Teores de taninos e produção de gases in vitro da silagem de sorgo com adição de níveis crescentes de guandu; Tannins Levels and gas production in vitro of sorghum silage with the addition of increasing levels of pigeon pea

Pinedo, Lerner Arévalo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/11/2009 PT
Relevância na Pesquisa
37.3%
Na alimentação animal, o sorgo pode ser explorado de diversas formas. Além dos grãos, a planta pode ser oferecida na forma de silagem, rolão, verde ou ainda pastejada; embora o valor nutritivo pode sofrer algumas variações pela presença ou ausência de compostos fenólicos como os taninos condensados. O objetivo deste trabalho foi avaliar a composição química-bromatológica, qualidade fermentativa e produção de gases in vitro nas silagens de sorgo granífero adicionados com diferentes níveis de guandu. O estudo foi dividido em dois experimentos. O primeiro estudo (Capítulo 3) avaliou os efeitos da adição de forragem de guandu sobre a composição química-bromatológica e fermentativas da silagem de sorgo granífero. Os tratamentos foram compostos por: T1 - Silagem com 100% de sorgo, T2 - Silagem com 25% de guandu e 75% de sorgo, T3 - Silagem com 50% de guandu e 50% de sorgo, T4 - Silagem com 75% de guandu e 25% de sorgo e T5 Silagem com 100% de guandu. As variáveis estudadas para a composição química e fermentativas das silagens foram: matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente neutro (FDA), carboidratos totais (CHOT), matéria mineral (MM), fenóis totais (FT)...

Anthocyanins and tannins in ozone-fumigated guava trees

de Rezende, Fernanda Mendes; Furlan, Claudia Maria
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 1445-1450
ENG
Relevância na Pesquisa
37.36%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 99/06971-9; Psidium guajava "Paluma", a tropical tree species, is known to be an efficient ozone indicator in tropical countries. When exposed to ozone, this species displays a characteristic leaf injury identified by inter-veinal red stippling on adaxial leaf surfaces. Following 30 days of three ozone treatments consisting of carbon filtered air (CF - AOT40 = 17 ppb h), ambient non-filtered air (NF - AOT40 = 542 ppb h) and ambient non-filtered air + 40 ppb ozone (NF + O(3) - AOT40 - 7802 ppb h), the amounts of residual anthocyanins and tannins present in 10 P. guajava ("Paluma") saplings were quantified. Higher amounts of anthocyanins were found in the NF + O(3) treatment (1.6%) when compared to the CF (0.97%) and NF (1.30%) (p < 0.05), and of total tannins in the NF + O(3) treatment (0.16%) compared to the CIF (0.14%). Condensed tannins showed the same tendency as enhanced amounts. Regression analyses using amounts of tannins and anthocyanins, AOT40 and the leaf injury index (LII), showed a correlation between the leaf injury index and quantities of anthocyanins and total tannins. These results are in accordance with the association between the incidence of red-stippled leaves and ozone polluted environments. (C) 2009 Elsevier Ltd. All rights reserved.

Anthelmintic effect of plant extracts containing condensed and hydrolyzable tannins on Caenorhabditis elegans, and their antioxidant capacity

Katiki, Luciana M.; Ferreira, Jorge F.S.; Gonzalez, Javier M.; Zajac, Anne M.; Lindsay, David S.; Chagas, Ana Carolina S.; Amarante, Alessandro F.T.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 218-227
ENG
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Although tannin-rich forages are known to increase protein uptake and to reduce gastrointestinal nematode infections in grazing ruminants, most published research involves forages with condensed tannins (CT), while published literature lacks information on the anthelmintic capacity, nutritional benefits, and antioxidant capacity of alternative forages containing hydrolyzable tannins (HT). We evaluated the anthelmintic activity and the antioxidant capacity of plant extracts containing either mostly CT, mostly HT, or both CT and HT. Extracts were prepared with 70% acetone, lyophilized, redissolved to doses ranging from 1.0mg/mL to 25mg/mL, and tested against adult Caenorhabditis elegans as a test model. The extract concentrations that killed 50% (LC50) or 90% (LC90) of the nematodes in 24h were determined and compared to the veterinary anthelmintic levamisole (8mg/mL). Extracts were quantified for CT by the acid butanol assay, for HT (based on gallic acid and ellagic acid) by high-performance liquid chromatography (HPLC) and total phenolics, and for their antioxidant activity by the oxygen radical absorbance capacity (ORAC) assay. Extracts with mostly CT were Lespedeza cuneata, Salix X sepulcralis, and Robinia pseudoacacia. Extracts rich in HT were Acer rubrum...

Salivary Amylase Induction by Tannin-Enriched Diets as a Possible Countermeasure Against Tannins

da Costa, G.; Lamy, E.; Capela e Silva, Fernando; Andersen, J.; Sales Baptista, E.; Coelho, A.V.
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica Formato: 55805 bytes; application/pdf
ENG
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Tannins are characterized by protein-binding affinity. They have astringent/bitter properties that act as deterrents, affecting diet selection. Two groups of salivary proteins, proline-rich proteins and histatins, are effective precipitators of tannin, decreasing levels of available tannins. The possibility of other salivary proteins having a co-adjuvant role on host defense mechanisms against tannins is unknown. In this work, we characterized and compared the protein profile of mice whole saliva from animals fed on three experimental diets: tannin-free diet, diet with the incorporation of 5% hydrolyzable tannins (tannic acid), or diet with 5% condensed tannins (quebracho). Protein analysis was performed by one-dimensional gel electrophoresis combined with Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry to allow the dynamic study of interactions between diet and saliva. Since abundant salivary proteins obscure the purification and identification of medium and low expressed salivary proteins, we used centrifugation to obtain saliva samples free from proteins that precipitate after tannin binding. Data from Peptide Mass Fingerprinting allowed us to identify ten different proteins, some of them showing more than one isoform. Tannin-enriched diets were observed to change the salivary protein profile. One isoform of α-amylase was overexpressed with both types of tannins. Aldehyde reductase was only identified in saliva of the quebracho group. Additionally...

The Effect of Tannins on Mediterranean Ruminant Ingestive Behavior: The Role of the Oral Cavity

Lamy, Elsa; Rawel, Harshadrai; Schweigert, Florian J.; Capela e Silva, Fernando; Ferreira, Ana; Costa, Ana Rodrigues; Antunes, Célia; Almeida, André Martinho; Coelho, Ana Varela; Sales-Baptista, Elvira
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
POR
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Abstract: Sheep, cattle and goat are domestic ruminants of significant economic interest in the Mediterranean region. Although sharing the same pasture ranges, they ingest different plants and plant parts and, consequently different levels of tannins. This suggests an ability to detect and adapt ingestion according to animal physiological limits of tolerance for plant secondary metabolites. This review will detail the effects of dietary tannins on feeding behavior, and the role of the oral cavity in this process, with focus on such ruminant species. The role of salivary protein profile in tannin perception in the oral cavity, and as a defense mechanism, will be discussed.

Effects of Condensed Tannins from Quebracho Extract on the Kinetic of in vitro Gas Production on Trifolium repens, Lotus corniculatus and Lolium perenne

Vieira, Sandrine C.; Borba, Alfredo Emílio Silveira de
Fonte: David Publishing Company Publicador: David Publishing Company
Tipo: Artigo de Revista Científica
Publicado em /11/2011 ENG
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The aim of this work was to study the effect of condensed tannins (CT) on the kinetic of gas production in vitro, on the three main species of Azorean pasture: Trifolium repens, Lotus corniculatus and Lolium perenne, using Quebracho extract as the source of CT, and also to calculate total tannins and condensed tannins on the species studied. Lotus corniculatus, Lolium perenne and Trifolium repens were tested in vitro with the inclusion of Quebracho extract in doses of 0%, 2.5% and 5% DM. The total content in tannins was determined in the 3 species. We have found, in comparison with standard tannic acid, that tannins exist in the flower of T. repens (0.81 equivalents of tannic acid) and in L .corniculatus (1.07 equivalents of tannic acid) but not in L .perenne (0 equivalents of tannic acid). The concentration of condensed tannins in the 3 species was: 0.34 mg/mL for T. repens; 0.83 mg/mL for L. corniculatus and 0 mg/ml for L. perenne. We verified that a significant reduction (P < 0.05) of gas production happened for doses of 5% of CT in comparison with the other two concentrations: 0% and 2.5% of CT. The results of this study express a reduction of the fermentation rate, which implies a reduction of gas production, so, a reduction of methane emission to the atmosphere and an increase of exploitation of the protein by ruminants.

Changes in enzymes, phenolic compounds, tannins, and vitamin C in various stages of jambolan (Syzygium cumini Lamark) development

Brandão,Taís Silva de Oliveira; Sena,Amanda Reges de; Teshima,Elisa; David,Jorge Maurício; Assis,Sandra Aparecida
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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The physiological state of a fruit is closely related to ripening and climatic conditions during the growing period when the fruit undergo changes in color, texture, and flavor. The ripening of the fruit can involve a complex series of biochemical reactions with alteration in enzymes activities, phenols, tannins, and ascorbic acid. The activity of enzymes (carboximethylcellulase, polygalacturonase, and pectinlyase), the total concentration of phenolic compounds, condensed tannins, and vitamin C in five stages of maturation were studied. Significant changes were observed between the maturity stages. The phenolic compounds were higher at green stage (705.01 ± 7.41); tannins were higher at green/purple stage (699.45 ± 0.22). The results showed that the ascorbic acid levels of the pulp varied significantly from 50.81 ± 1.43 to 6.61 ± 1.04 mg.100 g-1 during maturation. The specific activity of pectin lyase was higher at green stage (1531.90 ± 5.83). The specific activity of polygalacturonase was higher at mature stage (1.83 ± 0.0018). The specific activity of carboximetilcelulose was higher at ripe mature stage (4.61 ± 0.0024). The low ascorbic acid content found in jambolan fruit indicates that this fruit is not a rich source of this nutrient; however...

Seasonal variation in the content of tannins in barks of barbatimão species

Santos,Suzana C.; Costa,Wesley F.; Batista,Fernando; Santos,Lúcio R.; Ferri,Pedro H.; Ferreira,Heleno D.; Seraphin,José C.
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2006 EN
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The contents of tannins in the barks of barbatimão species, Stryphnodendron adstringens (Mart.) Cov. and S. polyphyllum (Mart.), were analysed monthly during one year. Results were correlated with climate conditions (rainfall, humidity and mean temperature) by chemometric methods. Principal component analysis of the data showed a tendency for higher production of tannins in the warm and wet season, suggesting that environmental factors can affect the levels of tannins in those plants.

Composition of condensed tannins from Calliandra calothyrsus and correlation with in sacco digestibility

Rakhmani, S.; Brooker, J.; Jones, G.; Palmer, B.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
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Calliandra calothyrsus accessions differ widely in digestibility for livestock. It is not clear, however, whether this is related to differences in condensed tannin levels or to other factors. Condensed tannins (CT) were extracted from seven different accessions of C. calothyrsus, and were examined for protein binding, pH stability of protein tannin complexes and CT composition. The compositional data was correlated with dry matter and nitrogen digestibility in sacco. Calliandra CT formed insoluble complexes with casein, bovine serum albumin and rubisco protein in an approximate ratio of 1:2 (w/w, tannin:protein) and the insoluble complexes were relatively stable to pH within the range of pH from 2.5 to 8.0. Polymeric proanthocyanidins were associated with both insoluble and soluble protein fractions, but the flavonols and flavonol glycosides were only associated with the soluble fraction. Total CT from each accession was fractionated by SepPak C18 reverse phase column chromatography into phenolic acids, monomers, oligomers/flavonols and polymeric proanthocyanidin fractions and quantified as total phenolics. There was wide variation between fractions across the seven accessions. Fractionation data were correlated with dry matter and nitrogen digestibility in sacco for each accession. Correlations were strongly negative (−0.799) and strongly positive (+0.800) for oligomers/flavonols and polymeric proanthocyanidins...

Mechanisms of defence against tannins by Streptococcus caprinus / Lisa Anne O'Donovan

O'Donovan, Lisa Anne
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 310630 bytes; application/pdf
Publicado em //1999 EN
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The inhibition of ruminant digestion by dietary tannins is a significant factor limiting livestock production... Characterisation of S. caprinus may provide essential insight into the ability of some ruminants to tolerate tannins. This thesis aims to identify and characterise the mechanism(s) by which Streptococcus caprinus tolerated the presence of tannins in its environment. S. caprinus employs at least two mechanisms to overcome the potential detrimental effects of tannins: degradation of tannic acid and production of a protective exopolysaccharide.; Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 2000; Bibliographical references: leaves 162-181.; 181, [64] leaves, [16] leaves of plates : ill. (some col.) ; 30 cm.; Title page, contents and abstract only. The complete thesis in print form is available from the University Library.

Phenolic Characterization of Commercial Enological Tannins

Peña Neira, Alvaro; Zamora Marín, Fernando; Ramírez Escudero, Cristián; López Solís, Remigio; Obreque Slier, Elías
Fonte: Universidade do Chile Publicador: Universidade do Chile
Tipo: Artículo de revista
EN
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Draft Manuscript for Review; Enological tannins are widely used in winemaking process to improve different characteristics of wines. A wide spectrum of enological tannins is now available on the market; however, the tannins’ chemical nature and botanical origin are not always clearly defined in the commercial products. The aim of this work was the chemical characterization of ten commercial plant-derived tanning agents of enological use. Enological tannins were analyzed by spectrophotometry (total phenols, total tannins and gelatin index) and High Performance Liquid Chromatography (HPLC-DAD) (low molecular weight phenolic compounds). In general it was possible observe important differences in the concentration of total phenols, total tannins and gelatin index values among the commercial products studied. By using HPLC-DAD it was possible classified different types of tannins (mainly hydrolyzable (gallotannins and ellagitannins), condensed or proanthocyanidic tannins and blends of these groups). Clear differences were evident between the study results and the information on the type of tannin indicated on some of the commercial tannin labels. These discrepancies could lead to technological problems in the winery industry because of the different aims that guide the use of different types of these enological products.

Identification of the origin of commercial enological tannins by the analysis of monosaccharides and polyalcohols

Sanz, Maria Luz; Martínez-Castro, Isabel; Moreno-Arribas, M. Victoria
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 24064 bytes; application/msword
ENG
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The monosaccharide and polyalcohol composition of 28-samples of different commercial tannins, including oak wood, grape seed and skin, plant gall, chestnut, quebracho and gambier, has been evaluated by gas chromatography-mass spectrometry after derivatization into their trimethylsilyl ethers. Quercitol was found to be characteristic of oak tannins, whereas gall plant tannins could be differentiated by their content of pinitol. Myo-inositol and arabitol were detected in tannins from quebracho. These polyalcohols, together with muco-inositol and chiro-inositol, were found in tannins from chestnut while bornesitol was found to be characteristic of tannins from gambier. Monosaccharide composition also helped to distinguish among tannin origins: arabinose, xylose, fructose and glucose were quantified in oak, quebracho and chestnut tannins, whereas only fructose and glucose were detected in plant gall and grape tannins. These results imply that the qualitative study of monosaccharides and polyalcohols could help to determine and control the authenticity of enological tannins.; This work was financed by Projects ANALISYC (S-2005/AGR-0312) and ALIBIRD (S-0505/AGR/000153) from the Comunidad de Madrid, and by Project AGL2006-04514 from the Spanish Ministerio de Educación y Ciencia.; Peer reviewed

Effect of different doses of quebracho tannins extract on rumen fermentation in ewes

Hervás, Gonzalo; Frutos, Pilar; Giráldez, Francisco Javier; Mantecón, Ángel R.; Álvarez del Pino, María C.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 94510 bytes; application/pdf
ENG
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14 pages, 1 figure, 5 tables.-- Available online Aug 23, 2003.; Previously published as proceeding at the XXXIII Jornadas de Estudio AIDA (IX Jornadas sobre Producción Animal). ITEA Vol. Extra 22 (Zaragoza, Spain, Apr 25-27, 2001). https://digital.csic.es/handle/10261/14343; Sixteen Merino ewes, fitted with ruminal cannulae, were divided into four groups of four, with the aim of studying effects of different doses of quebracho tannins on rumen fermentation in sheep. Zero (control, Q0), 0.5 (Q1), 1.5 (Q2) and 3.0 g (Q3) of quebracho tannins extract (containing 76% condensed tannins (CTs)) per kg LW per day (equivalent to 0, 28, 83 and 166 g/kg DM (dry matter) feed, respectively) were intra-ruminally administered, for up to 21 days. The rumen in sacco technique was used to examine in situ DM, crude protein (CP), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF) disappearances, and a gas production method was used to examine rate and extent of in vitro gas production and in vitro dry matter disappearance (ivDMD). Alfalfa hay (AH), barley straw (BS) and Erica arborea (EA) were used in all the incubations. In vivo pH and ammonia-N and volatile fatty acid concentrations were also measured. Ewes from groups Q0, Q1 and Q2 remained healthy throughout the experiment and consumed the entire ration offered. However...

Review. Tannins and ruminant nutrition; Revisión. Taninos y nutrición de rumiantes

Frutos, Pilar; Hervás, Gonzalo; Giráldez, Francisco Javier; Mantecón, Ángel R.
Fonte: Instituto Nacional de Investigaciones Agrarias (España) Publicador: Instituto Nacional de Investigaciones Agrarias (España)
Tipo: Artículo Formato: 67653 bytes; application/pdf
ENG
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12 páginas.; [EN] Tannins are a complex group of polyphenolic compounds found in a wide range of plant species commonly consumed by ruminants. They are conventionally classified into two major groups: the hydrolysable and the condensed tannins. Although for a long time tannins were thought to be detrimental to ruminants, their effect may be either beneficial or harmful depending on the type of tannin consumed, its chemical structure and molecular weight, the amount ingested, and the animal species involved. High concentrations of tannins reduce voluntary feed intake and nutrient digestibility, whereas low to moderate concentrations may improve the digestive utilisation of feed mainly due to a reduction in protein degradation in the rumen and a subsequent increase in amino acid flow to the small intestine. These effects on nutrition are reflected in animal performance.; [ES] Los taninos son un grupo muy diverso de compuestos fenólicos que aparecen en una amplia variedad de plantas consumidas por los rumiantes. Tradicionalmente se han dividido, de forma simplista, en hidrolizables y condensados. Aunque durante mucho tiempo se pensó que los taninos eran negativos para los rumiantes, su efecto puede ser beneficioso o perjudicial dependiendo del tipo de tanino...

An in vitro study on the ability of polyethylene glycol to inhibit the effect of quebracho tannins and tannic acid on rumen fermentation in sheep, goats, cows, and deer

Frutos, Pilar; Hervás, Gonzalo; Giráldez, Francisco Javier; Mantecón, Ángel R.
Fonte: CSIRO Publishing Publicador: CSIRO Publishing
Tipo: Artículo Formato: 94510 bytes; application/pdf
ENG
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8 pages.; Batch cultures of rumen microorganisms, using rumen fluids from 4 ruminant species, sheep, goats, cows, and deer, were used to study the ability of polyethylene-glycol (PEG 6000) to inhibit the effect of 2 types of tannins, quebracho (QUE, a condensed tannin) and tannic acid (TA, a hydrolysable tannin) on several in vitro rumen fermentation characteristics. Both QUE and TA were able to impair ruminal fermentation (they reduced gas production, extent of degradation, ammonia-N, and volatile fatty acid concentrations, etc.; P < 0.05), with differences depending on the inoculum donor. The clearest effect of tannins was the reduction of the rates of fermentation, which was observed in all species (P < 0.05). The detrimental effects of tannins were removed by the presence of PEG in most cases, but there were important variations and noticeable exceptions. Thus, for instance, PEG failed to revert the negative effect of TA on the rate of fermentation and the extent of degradation (P < 0.05). The extent of the limited ability of PEG to completely inhibit the negative effects of tannins on in vitro ruminal fermentation seems to depend both on the type of tannin and the species of the rumen inoculum donor.; Peer reviewed

Study by infrared spectroscopy and thermogravimetric analysis of Tannins and Tannic acid

Pantoja-Castro,Mayra A.; González-Rodríguez,Horacio
Fonte: Laboratorios Mixim S.A. Publicador: Laboratorios Mixim S.A.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 EN
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Among the compounds in nature useful for people are tannins, which present large molecular complexity and they had have an ancient use as tanning agents, and nowadays some of them are used due their antioxidant properties for protect metals of corrosion. Also elucidation, synthesis and purification represent a great challenge to obtain them. Due this fact researches have tried to copy the synthesis of less complex compounds similar to tannins. From a different point of view, the use of tannins extracted from trees bark, considered in many places as a waste, grant an extra value to the bark. In this work we have studied and analyzed through gel permeation chromatography (GPC), infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) the average molecular weight, main functional groups and thermal properties of tannins extracted from Schinopsis quebracho colorado. The results of these analyses are compared with those obtained for the commercial grade tannic acid. The comparison allowed to corroborate that is possible to use tannins from the Schinopsis quebracho colorado bark, with functional groups and thermal properties which tend to be similar to the tannic acid.

Changes in grape seed, skin and pulp condensed tannins during berry ripening: effect of fruit pruning

Ó-Marques,João do; Reguinga,Rui; Laureano,Olga; Ricardo-da-Silva,Jorge M.
Fonte: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional) Publicador: INIAV - DOIS PORTOS (Ex-Estação Vitivinícola Nacional)
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
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The purpose of the present work was to study the evolution of condensed tannins according to their degree of polymerization in seeds, pulp and skins, along the maturation using Cabernet Sauvignon and Tinta Roriz (Vitis vinifera L.) varieties. Additionally for this study a witness of each variety was compared with two modalities of fruit pruning, one of 50% and another one of 75%. Quantitative changes in the condensed tannins with different degree of polymerization were measured using fractionation on C18 Sep-Pak cartridges followed by reaction with vanillin, and also by HPLC. The results showed that for both two varieties and respective modalities, the concentration of condensed tannins (whatever the degree of polymerization) in any part of grape berry (pulp, seeds and skins) were gradually decreased throughout the ripening period. At harvest, several major analytical parameters of grape berries of the two varieties and for two modalities were not significantly changed. However, significant difference was observed in condensed tannin levels between the control and the pruning modalities.