A study was conducted to determine if sainfoin, a condensed tannin (CT) containing legume, fed to beef cattle as hay or silage during a western Canadian winter would result in a reduction in methane (CH4) emissions without compromising animal performance. Forty yearling beef steers were fed four diets in a factorial design consisting of two legume forage species (sainfoin or alfalfa) and two preservation methods (silage or hay) over 15 weeks (wks). For each sample wk, animal weight, 24-h CH4 expiration and rumen fluid samples were obtained. Rumen methanogens were characterized using terminal restriction fragment length polymorphisms analysis. Specific bacteria were quantified with real-time polymerase chain reaction analysis. Sainfoin silage (SS) and sainfoin hay (SH) contained 11.9 and 10.5 mg g-1 of CT respectively and supported an acceptable growth rate for backgrounding steers. A decline (P < 0.05) in enteric CH4 formation could only be detected from SH-fed animals compared to alfalfa hay (AH) fed animals when CH4 was expressed as L d-1 or L kg BW-1. The rumen archaeal community structure of experimental animals remained stable regardless of diet type or sample wk. Structural carbohydrate-fermenting bacteria were suppressed in silage diets. Methanogens were less abundant in the rumen fluid samples of steers fed SS but not SH.

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xix, 184 p.; also contains graphics (some col.). Includes abstract and vita. Advisor: Patrick G. Hatcher, Dept. of Chemistry. Includes bibliographical references (p. 168-184).

Sorghum and maize grain hardness is a very important criterion as grain hardness affects milling yield and product quality. There are several techniques that are used to determine grain hardness but the relationship between these techniques for distinguishing hardness in commercial sorghum and maize cultivars is not known. Moreover, the role of sorghum grain hardness with respect to malting performance is not understood, as is the role of phenolics in sorghum and maize hardness. Therefore this study investigated the relationships between sorghum and maize hardness techniques, and the influence of sorghum grain modification during malting and sorghum and maize phenolics on the hardness of these cereals. A study to determine the relationships between techniques used to measure hardness in commercial sorghum and maize cultivars was done in terms of decortication using the Tangential Abrasive Dehulling Device (TADD) (percentage kernel removed), Near Infrared Transmittance (NIT) Milling Index (MI), test weight (TW), thousand kernel weight (TKW), kernel size (KS), stress cracking (SC) and susceptibility to breakage (SB). It was found that not all grain quality techniques were related to each other. In non-tannin sorghum, TADD hardness, TW, TKW and kernel size > 3.35 mm were correlated and can be used to select for hardness. In maize, TADD hardness, NIT Milling Index and TW would be suitable for hardness evaluation. The influence of malting on sorghum hardness was monitored for a period of five days following steeping. The results showed that hardness parameters including pycnometer density, floaters, TADD hardness, TKW, Single Kernel Characterisation System-Hardness Index (SKCS-HI) reduced drastically by Day 2 of malting. TADD hardness was not correlated with Diastatic Power (DP), which could be attributed to inefficient decortication due to the softening of the grain outer layers, reduced dry matter (malting loss), loss of kernel orientation and endosperm collapse during endosperm modification. However, sorghum with high DP corresponded with low values of the measured hardness parameters. Thus, in sorghum with high DP amylases accessed the starchy endosperm faster, hence the decrease in hardness. Scanning electron microscopy (SEM) confirmed that modification was influenced by amylase activity and cultivars with low amylase modified slower than those with high amylase. Hence, amylase activity was more influential in malt hardness than original grain hardness. The phenolic acids in sorghum and maize bran and flour fractions were determined using HPLC-MS/MS. The phenolic acid content of the grain fractions was correlated with the grain hardness values. Maize bran ferulic acid content was more strongly correlated with TADD hardness but with sorghum, the relationship was weaker. Using HPLC-MS/MS, four diferulic acids were identified in sorghum and maize bran namely 8-5', 5-5', 8-O-4' and 8-5'- benzofuran form in quantities at least seven times less than ferulic acid. However, there was no correlation found between diferulic acids and hardness properties of both cereals. This study shows that TADD hardness and TW are an excellent way of estimating both sorghum and maize hardness that can be applied for cultivar evaluation. The study indicates that two days of malting would be sufficient to obtain malt suitable for milling. Ferulic acid of maize and sorghum bran seems to influence grain hardness of these cereals probably through cross-linking to arabinoxylan chains in the pericarp, hence reinforcing cell wall strength. / Thesis (PhD)--University of Pretoria, 2012. / Food Science / unrestricted

No description available.

No description available.

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.

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.

No description available.

There is interest in increasing the content of omega-3 (n-3; e.g., linolenic acid [C18:3n3]) fatty acids and conjugated linoleic acid (CLA) in bovine milk, primarily because of their beneficial effects on human health. One strategy to alter bovine milk fatty acid composition is the dietary inclusion of flaxseed, which is a rich source of C18:3 n-3. The aim of this study was to evaluate the effects of extrusion processing of flaxseed and the inclusion of condensed tannins (CT) in a flaxseed supplement on omasal flow of nutrients, ruminal fermentation characteristics, animal performance, and milk fatty acid profiles in dairy cattle. Eight multiparous Holstein cows (712.7 ± 92.3 kg body weight; 116.5 ± 17.5 days-in-milk at the beginning of the study) were assigned to four dietary treatments in a replicated 4 x 4 Latin square design consisting of 28-d periods with 20 d of dietary adaptation. Four cows in one Latin square were ruminally-cannulated to allow ruminal and omasal sampling. Cows were fed either a control diet (CTL) or one of 3 treatment diets that consisted of the daily substitution of 3 kg (DM basis) of the CTL concentrate pellet with 3 kg (DM basis) of either a non-extruded flaxseed and pea product (55% flax¬seed, 36% peas, 8% alfalfa, 1% antioxidant; designated RAW), a extruded flaxseed and pea product (55% flaxseed, 36% peas, 8% alfalfa, 1% anti¬oxidant; designated LPR), or a extruded flaxseed and high-tannin fava bean product (55% flaxseed, 36% high-tannin faba beans, 8% alfalfa, 1% antioxidant; designated LPF). Diets were fed twice daily as total mixed rations. Omasal flow of nutrients was estimated using the omasal sampling technique using iNDF as the single indigestible marker. Dry matter intake was lower (P = 0.01) in cows fed the flaxseed diets (24.0 kg/d) compared to those fed CTL (25.9 kg/d). Milk yield was higher (P = 0.02) in cows fed the LPR diet ( 44.4 kg/d) compared to those fed the RAW diet ( 42.3 kg/d); and tended to be higher (P = 0.07) in cows fed the flaxseed diets compared to those fed the CTL diet. Milk fat yield was unaffected by dietary treatment (P = 0.94), whereas milk protein yield tended (P = 0.10) to increase in cows fed the flaxseed diets compared to those fed the CTL diet. No detrimental effects of dietary treatments on ruminal fermentation and omasal flow of microbial protein were observed. The omasal flow of C18:3 n-3 was higher in cows fed the flaxseed diets compared to those fed the CTL diet (P = 0.04), with the RAW diet (56.9 g/d) having the highest flow of C18: 3n-3 compared to the other diets (LPR = 14.0 g/d; LPF = 14.8 g/d). The omasal flow of total CLA isomers were higher (P = 0.03) in cows fed the LPF diet (6.06 g/d) compared to those fed the LPR diet (3.70 g/d). The C18:3 n-3 content in milk fat (% of fatty acid methyl esters) was higher in cows fed the LPR diet (0.950%) compared to those fed the RAW diet (0.745%). The level of total CLA isomers in milk was also higher in cows fed the LPR diet (0.845%) compared to those fed the RAW diet (0.308%). These results demonstrated that feeding extruded flaxseed products is more effective than feeding whole flaxseed at improving the fatty acid composition of milk fat without negatively impacting animal performance and ruminal fermentation; however, the inclusion of CT in the extruded flaxseed product had no additional benefit.

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.