Enrichment and Identification of Lignin−Carbohydrate Complexes in Softwood Extract

Lignin-carbohydrate complexes (LCCs) are hybrid structures containing covalently linked moieties of lignin and carbohydrates. The structure and behavior of LCCs affect both industrial processes and practical applications of lignocellulosic biomass. However, the identification of phenylglycoside, benzylether, and gamma (gamma)-ester LCC bonds in lignocellulosic biomass is limited due to their relatively low abundance compared to plain carbohydrate and lignin structures. Herein, we enriched the LCC bonds in softwood galactoglucomannan (GGM)-rich extract fractionated by (1) a solvent (ethanol), (2) enzymes, and (3) physical techniques. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy analysis was used to identify the LCC bonds. Phenylglycoside and benzylether bonds were concentrated in the ethanol-soluble GGM fractions. A benzylether bond was concentrated into GGM fractions containing larger molecules (>500 Da) through physical techniques. The gamma-ester bond was identified in all studied GGM fractions, which is explained by its stability and possible presence in residual xylan. In summary, we demonstrated the potential of the suggested techniques to enrich LCC bonds in softwood extract and improve LCC identification. Such techniques may also enable further studies on the structure and functionality of LCC bonds and open new prospects in the engineering of biomolecules.Peer reviewe

Narrow-leafed lupin (Lupinus angustifolius L.): Characterization of emulsification and fibre properties

Lupin is among the most promising plant-based food protein sources due to its high protein and fibre content. The fibre fraction, especially from seed coats, is often seen as low in value (discarded as waste or as animal feed) and greater knowledge on its composition and structure are crucial to increase its usefulness. However, only one model of lupin fibre structure exists in the literature. Our sample of Finnish-grown narrow-leafed lupin seed consisted of fibre (43.3%), protein (31.3%), fat (8.1%) and starch (0.2%). According to the sugar analysis, rhamnogalacturonan-I, with branches of arabinan and galactan, constituted the main pectin population in the fibre fraction. A revised model of the overall fibre structure is proposed. At concentrations of 0.75% and 1.0%, both unrefined and defatted flour of whole lupin seeds produced stable suspensions and oil-in-water emulsions, demonstrating their application as potential emulsifiers. This study presents the knowledge and opportunity to support sustainability through the utilization of whole lupin seed for future industrial applications.Peer reviewe

Impact of birch xylan composition and structure on film formation and properties

Commercial birch xylan (CX) and alkali-soluble birch xylan (ASX) were subjected to controlled acetylation and used for film formation in the presence (20% and 40%) or absence of plasticizers (i.e. glycerol, sorbitol and xylitol). Although the content of Klason lignin was similar (1.2-1.4%), the acetylation process was favored by the high-purity CX (97% xylan) over the ASX (89% xylan). On the other hand, the presence of residual pectin heteropolysaccharides rather than xylan in the ASX sample was beneficial for film formation. These heteropolysaccharides seemed to act as natural plasticizers during film formation, allowing the formation of coherent films from ASX, even in the absence of an external plasticizer. The use of plasticizers favored the mechanical properties of films, especially in a dosage of 40%, when plastic behavior was created. Acetylation favored the film formation and slightly improved the mechanical properties of the films, and this improvement was in the same range as that achieved when using 20% plasticizer in non-acetylated ASX.Peer reviewe

STUDY OF THE BLEACHABILITY OF EUCALIPTUS KRAFT PULP

O objetivo do estudo foi avaliar de que modo a branqueabilidade da polpa se correlaciona com as caracter\uedsticas qu\uedmicas da madeira, as condi\ue7\uf5es de polpa\ue7\ue3o, o grau de deslignifica\ue7\ue3o da polpa marrom (n\ufamero kappa) e as sequ\ueancias de branqueamento, baseando-se na alvura da polpa branqueada, viscosidade, consumo de qu\uedmicos de branqueamento e branqueabilidade da polpa. As madeiras de eucalipto (A, B e C), devidamente caracterizadas quanto aos constituintes qu\uedmicos (holocelulose, teor de ligninas insol\ufavel e sol\ufavel, teor de extrativos totais, cinzas e cinzas insol\ufaveis em \ue1cido clor\ueddrico) foram utilizadas para a produ\ue7\ue3o de polpa celul\uf3sica atrav\ue9s de duas condi\ue7\uf5es de polpa\ue7\ue3o kraft modificada: Condi\ue7\ue3o I (PI) - \ue1lcali efetivo de 16,5%, sulfidez de 30% e temperatura de cozimento de 155\ub0C; e Condi\ue7\ue3o II (PII) - \ue1lcali efetivo de 17,5%, sulfidez de 32% e temperatura de cozimento de 147\ub0C. Ambos os cozimentos foram realizados buscando-se n\ufamero kappa de 15,5 \ub1 0,5 e de 18,0 \ub1 0,5. Os par\ue2metros de polpa\ue7\ue3o e as propriedades das polpas marrons avaliados foram: rendimento depurado, viscosidade, alvura, teor de \ue1cidos hexenur\uf4nicos e o \uedndice k/kappa corrigido (raz\ue3o entre o \uedndice de absor\ue7\ue3o de luz, um dos termos da f\uf3rmula da alvura, e o valor do n\ufamero kappa corrigido, descontando a contribui\ue7\ue3o dos \ue1cidos hexenur\uf4nicos). Cada uma das polpas foi branqueada, at\ue9 90% ISO de alvura, seguindo tr\ueas sequ\ueancias de branqueamento pr\ue9-definidas: Sequ\ueancia 1 - OA(ZE)DP; Sequ\ueancia 2 - OA/D(EOP)DP; e Sequ\ueancia 3 \u2013 OD(EOP)DP. As polpas branqueadas foram avaliadas quanto \ue0 alvura, viscosidade, consumo de qu\uedmicos de branqueamento e branqueabilidade. A branqueabilidade das polpas foi afetada pela madeira. Al\ue9m disso, as branqueabilidades sofreram influ\ueancia da condi\ue7\ue3o de polpa\ue7\ue3o e do n\ufamero kappa da polpa marrom. As Sequ\ueancias de branqueamento 1 e 2 mostraram-se satisfat\uf3rias para a produ\ue7\ue3o de polpa na alvura de interesse (90 \ub1 1% ISO), diferentemente do verificado para as polpas produzidas pela Sequ\ueancia 3. As melhores branqueabilidades foram obtidas para as polpas com n\ufamero kappa da polpa marrom de 18,0 \ub1 0,5. Verificou-se estreita correla\ue7\ue3o entre branqueabilidade e \uedndice k/kappa corrigido o que indicou a possibilidade de se utilizar esta propriedade da polpa marrom para a predi\ue7\ue3o de branqueabilidades de polpas.The aim of this study was to evaluate how the pulp bleachability ability is correlated with the wood chemical characteristics, the cooking conditions, the kappa number of the brown pulp and the bleaching sequences, based on the pulp bleached brightness, viscosity, bleaching chemical consumption and bleachability. The eucalyptus wood (A, B, and C), appropriately characterized as the chemical constituents (holocellulose content, insoluble and soluble lignin content, total extractive content, ash and insoluble ash in hydrochloric acid) were used for pulp production by modified kraft cooking, using two different pulping conditions: Condition I (PI) - 16.5% effective alkali, 30% sulfide, and 155\ub0C cooking temperature; and Condition II (PII) - 17.5% effective alkali, 32% sulfide, and 147\ub0C cooking temperature. Both conditions were performed to kappa number 15.5 \ub1 0.5 and 18.0 \ub1 0.5. The pulping parameters and pulp properties evaluated were: screened yield, viscosity, brightness, hexenuronic acid content, and index k/corrected kappa (ratio between the light absorption rate, a brightness formula term, and the corrected kappa number, disregarding the hexenuronic acid contribution). Each one of the pulps was bleached, to achieve 90 \ub1 1% ISO brightness, following three pre-defined bleaching sequences: 1 Sequence - OA(ZE)DP; 2 Sequence - OA/D(EOP)DP; and 3 Sequence - OD(EOP)DP. The pulps were investigated for brightness, viscosity, bleaching chemical consumption and bleachability. The bleachability was affected by the wood. Furthermore, the bleaching abilities were affected by the cooking condition and the brown pulp kappa number. The 1 and 2 sequences were satisfactory to achieve the required brightness (90 \ub1 1% ISO) unlike to the verified to the 3 sequence. The best bleachabilities were obtained from the brown pulps with higher kappa number 18.0 \ub1 0.5. It was verified close correlation between bleaching ability and index k/corrected kappa, which indicated the possibility of using this property of unbleached pulp for predicting pulp bleachability

Efeito da qualidade da madeira no desempenho da polpação kraft

O objetivo do estudo foi avaliar o efeito da qualidade de madeiras de eucalipto no desempenho da polpação kraft sob duas diferentes condições de polpação e em dois níveis de deslignificação, baseando-se no rendimento, alvura, viscosidade e índice k/kappa corrigido das polpas produzidas. As madeiras de eucalipto (A, B e C), foram analisadas quanto às suas propriedades físico-químicas (densidades básica e aparente, teor de ligninas insolúvel e solúvel, teor de extrativos, cinzas e cinzas insolúveis em ácido clorídrico) e utilizadas para a produção de polpa celulósica por meio do cozimento kraft modificado, utilizando duas condições de polpação, sendo elas: Condição I (PI) - álcali efetivo de 16,5%, sulfidez de 30% e temperatura de cozimento de 155ºC; e Condição II (PII) - álcali efetivo de 17,5%, sulfidez de 32% e temperatura de cozimento de 147ºC. Ambos os cozimentos foram realizados buscando-se no número kappa de 15,5 ± 0,5 e de 18,0 ± 0,5. Foram avaliados os seguintes parâmetros de polpação e propriedades das polpas produzidas: fator H, rendimento depurado, viscosidade, alvura, conteúdo de ácidos hexenurônicos e o índice k/kappa corrigido. A madeira A, que apresentou menores teores de extrativos e lignina em sua constituição, bem como menores densidades básica e aparente quando comparada com as madeiras B e C, apresentou os melhores resultados para os parâmetros de cozimento avaliados, com destaque para a polpa produzida pela condição de cozimento PII com o número kappa de (18,0 ± 0,5), que apresentou maior rendimento, alvura e viscosidade dentre todas as polpas produzidas. Polpas produzidas com maior número kappa apresentam menores índices k/kappa corrigidos.The aim of this study was to evaluate the wood quality in the kraft pulping performance under two different pulping conditions at two delignification degrees based on results for the yield, brightness, viscosity, and k/kappa corrected index. Eucalyptus wood (A, B, and C) was analyzed about their physicochemical properties (basic and apparent density, insoluble and soluble lignin content, extractive content, ash and insoluble ash in hydrochloric acid) and used for pulp production by modified kraft cooking, using two different pulping conditions: Condition I (PI) - 16.5% effective alkali, 30% sulfidity, and 155º of cooking temperature; and Condition II (PII) - 17.5% effective alkali, 32% sulfidity,and 147ºC cooking temperature. Both conditions were performed to kappa number 15.5 ± 0.5 and 18.0 ± 0.5. The following pulping parameters and pulp properties produced were evaluated: H factor, screened yield, viscosity, brightness, hexenuronic acid content, and the k/kappa corrected index. The A wood, which had lower extractives and lignin content in its constitution, as well as lower basic and apparent density when compared with B and C woods, showed good results for cooking parameters, especially the pulp produced at PII condition at kappa number 18.0 ± 0.5.Also, the A wood showed higher screened yield, brightness, and viscosity comparing to the other pulps produced. Those pulps produced with higher kappa number have lower k/kappa corrected index

ESTUDO DA BRANQUEABILIDADE DA POLPA KRAFT DE EUCALIPTO

http://dx.doi.org/10.5902/1980509817476The aim of this study was to evaluate how the pulp bleachability ability is correlated with the wood chemical characteristics, the cooking conditions, the kappa number of the brown pulp and the bleaching sequences, based on the pulp bleached brightness, viscosity, bleaching chemical consumption and bleachability. The eucalyptus wood (A, B, and C), appropriately characterized as the chemical constituents (holocellulose content, insoluble and soluble lignin content, total extractive content, ash and insoluble ash in hydrochloric acid) were used for pulp production by modified kraft cooking, using two different pulping conditions: Condition I (PI) - 16.5% effective alkali, 30% sulfide, and 155ºC cooking temperature; and Condition II (PII) - 17.5% effective alkali, 32% sulfide, and 147ºC cooking temperature. Both conditions were performed to kappa number 15.5 ± 0.5 and 18.0 ± 0.5. The pulping parameters and pulp properties evaluated were: screened yield, viscosity, brightness, hexenuronic acid content, and index k/corrected kappa (ratio between the light absorption rate, a brightness formula term, and the corrected kappa number, disregarding the hexenuronic acid contribution). Each one of the pulps was bleached, to achieve 90 ± 1% ISO brightness, following three pre-defined bleaching sequences: 1 Sequence - OA(ZE)DP; 2 Sequence - OA/D(EOP)DP; and 3 Sequence - OD(EOP)DP. The pulps were investigated for brightness, viscosity, bleaching chemical consumption and bleachability. The bleachability was affected by the wood. Furthermore, the bleaching abilities were affected by the cooking condition and the brown pulp kappa number. The 1 and 2 sequences were satisfactory to achieve the required brightness (90 ± 1% ISO) unlike to the verified to the 3 sequence. The best bleachabilities were obtained from the brown pulps with higher kappa number 18.0 ± 0.5. It was verified close correlation between bleaching ability and index k/ corrected kappa, which indicated the possibility of using this property of unbleached pulp for predicting pulp bleachability. http://dx.doi.org/10.5902/1980509817476O objetivo do estudo foi avaliar de que modo a branqueabilidade da polpa se correlaciona com as características químicas da madeira, as condições de polpação, o grau de deslignificação da polpa marrom (número kappa) e as sequências de branqueamento, baseando-se na alvura da polpa branqueada, viscosidade, consumo de químicos de branqueamento e branqueabilidade da polpa. As madeiras de eucalipto (A, B e C), devidamente caracterizadas quanto aos constituintes químicos (holocelulose, teor de ligninas insolúvel e solúvel, teor de extrativos totais, cinzas e cinzas insolúveis em ácido clorídrico) foram utilizadas para a produção de polpa celulósica através de duas condições de polpação kraft modificada: Condição I (PI) - álcali efetivo de 16,5%, sulfidez de 30% e temperatura de cozimento de 155ºC; e Condição II (PII) - álcali efetivo de 17,5%, sulfidez de 32% e temperatura de cozimento de 147ºC. Ambos os cozimentos foram realizados buscando-se número kappa de 15,5 ± 0,5 e de 18,0 ± 0,5. Os parâmetros de polpação e as propriedades das polpas marrons avaliados foram: rendimento depurado, viscosidade, alvura, teor de ácidos hexenurônicos e o índice k/kappa corrigido (razão entre o índice de absorção de luz, um dos termos da fórmula da alvura, e o valor do número kappa corrigido, descontando a contribuição dos ácidos hexenurônicos). Cada uma das polpas foi branqueada, até 90% ISO de alvura, seguindo três sequências de branqueamento pré-definidas: Sequência 1 - OA(ZE)DP; Sequência 2 - OA/D(EOP)DP; e Sequência 3 – OD(EOP)DP. As polpas branqueadas foram avaliadas quanto à alvura, viscosidade, consumo de químicos de branqueamento e branqueabilidade. A branqueabilidade das polpas foi afetada pela madeira. Além disso, as branqueabilidades sofreram influência da condição de polpação e do número kappa da polpa marrom. As Sequências de branqueamento 1 e 2 mostraram-se satisfatórias para a produção de polpa na alvura de interesse (90 ± 1% ISO), diferentemente do verificado para as polpas produzidas pela Sequência 3. As melhores branqueabilidades foram obtidas para as polpas com número kappa da polpa marrom de 18,0 ± 0,5. Verificou-se estreita correlação entre branqueabilidade e índice k/kappa corrigido o que indicou a possibilidade de se utilizar esta propriedade da polpa marrom para a predição de branqueabilidades de polpas

WOOD QUALITY EFFECT ON KRAFT PULPING PERFORMANCE

O objetivo do estudo foi avaliar o efeito da qualidade de madeiras de eucalipto no desempenho da polpa\ue7\ue3o kraft sob duas diferentes condi\ue7\uf5es de polpa\ue7\ue3o e em dois n\uedveis de deslignifica\ue7\ue3o, baseando-se no rendimento, alvura, viscosidade e \uedndice k/kappa corrigido das polpas produzidas. As madeiras de eucalipto (A, B e C), foram analisadas quanto \ue0s suas propriedades f\uedsico-qu\uedmicas (densidades b\ue1sica e aparente, teor de ligninas insol\ufavel e sol\ufavel, teor de extrativos, cinzas e cinzas insol\ufaveis em \ue1cido clor\ueddrico) e utilizadas para a produ\ue7\ue3o de polpa celul\uf3sica por meio do cozimento kraft modificado, utilizando duas condi\ue7\uf5es de polpa\ue7\ue3o, sendo elas: Condi\ue7\ue3o I (PI) - \ue1lcali efetivo de 16,5%, sulfidez de 30% e temperatura de cozimento de 155\ub0C; e Condi\ue7\ue3o II (PII) - \ue1lcali efetivo de 17,5%, sulfidez de 32% e temperatura de cozimento de 147\ub0C. Ambos os cozimentos foram realizados buscando-se no n\ufamero kappa de 15,5 \ub1 0,5 e de 18,0 \ub1 0,5. Foram avaliados os seguintes par\ue2metros de polpa\ue7\ue3o e propriedades das polpas produzidas: fator H, rendimento depurado, viscosidade, alvura, conte\ufado de \ue1cidos hexenur\uf4nicos e o \uedndice k/kappa corrigido. A madeira A, que apresentou menores teores de extrativos e lignina em sua constitui\ue7\ue3o, bem como menores densidades b\ue1sica e aparente quando comparada com as madeiras B e C, apresentou os melhores resultados para os par\ue2metros de cozimento avaliados, com destaque para a polpa produzida pela condi\ue7\ue3o de cozimento PII com o n\ufamero kappa de (18,0 \ub1 0,5), que apresentou maior rendimento, alvura e viscosidade dentre todas as polpas produzidas. Polpas produzidas com maior n\ufamero kappa apresentam menores \uedndices k/kappa corrigidos.The aim of this study was to evaluate the wood quality in the kraft pulping performance under two different pulping conditions at two delignification degrees based on results for the yield, brightness, viscosity, and k/ kappa corrected index. Eucalyptus wood (A, B, and C) was analyzed about their physicochemical properties (basic and apparent density, insoluble and soluble lignin content, extractive content, ash and insoluble ash in hydrochloric acid) and used for pulp production by modified kraft cooking, using two different pulping conditions: Condition I (PI) - 16.5% effective alkali, 30% sulfidity, and 155\ub0 of cooking temperature; and Condition II (PII) - 17.5% effective alkali, 32% sulfidity,and 147\ub0C cooking temperature. Both conditions were performed to kappa number 15.5 \ub1 0.5 and 18.0 \ub1 0.5. The following pulping parameters and pulp properties produced were evaluated: H factor, screened yield, viscosity, brightness, hexenuronic acid content, and the k/kappa corrected index. The A wood, which had lower extractives and lignin content in its constitution, as well as lower basic and apparent density when compared with B and C woods, showed good results for cooking parameters, especially the pulp produced at PII condition at kappa number 18.0 \ub1 0.5.Also, the A wood showed higher screened yield, brightness, and viscosity comparing to the other pulps produced. Those pulps produced with higher kappa number have lower k/kappa corrected index

Branqueamento de polpa de eucalipto com sequências curtas

Eucalyptus spp kraft pulp, due to its high content of hexenuronic acids, is quite easy to bleach. Therefore, investigations have been made attempting to decrease the number of stages in the bleaching process in order to minimize capital costs. This study focused on the evaluation of short ECF (Elemental Chlorine Free) and TCF (Totally Chlorine Free) sequences for bleaching oxygen delignified Eucalyptus spp kraft pulp to 90% ISO brightness: PMoDP (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide), PMoD/P (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, without washing) PMoD(PO) (Molybdenum catalyzed acid peroxide, chlorine dioxide and pressurized peroxide), D(EPO)DP (chlorine dioxide, extraction oxidative with oxygen and peroxide, chlorine dioxide and hydrogen peroxide), PMoQ(PO) (Molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide), and XPMoQ(PO) (Enzyme, molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide). Uncommon pulp treatments, such as molybdenum catalyzed acid peroxide (PMo) and xylanase (X) bleaching stages, were used. Among the ECF alternatives, the two-stage PMoD/P sequence proved highly cost-effective without affecting pulp quality in relation to the traditional D(EPO)DP sequence and produced better quality effluent in relation to the reference. However, a four stage sequence, XPMoQ(PO), was required to achieve full brightness using the TCF technology. This sequence was highly cost-effective although it only produced pulp of acceptable quality.A polpa kraft de Eucalyptus spp., em razão do elevado conteúdo de ácidos hexenurônicos, é relativamente fácil de ser branqueada Dessa forma, estudos têm sido feitos para diminuir o número de estágios de branqueamento na planta, minimizando assim importantes custos do processo. Este estudo teve como objetivo a avaliação de sequências curtas de branqueamento ECF (Elemental Chlorine Free) e TCF (Totally Chlorine Free): PMoDP (Peróxido de hidrogênio catalisado com molibdênio, seguido por estágios de dióxido de cloro e peróxido de hidrogênio), PMoD/P (Peróxido de hidrogênio catalisado com molibdênio, dióxido de cloro e peróxido de hidrogênio, sem lavagem entre os dois últimos estágios), PMoD(PO) (Peróxido de hidrogênio catalisado com molibdênio, dióxido de cloro e peróxido de hidrogênio pressurizado), D(EPO)DP (Dióxido de cloro, extração oxidativa com oxigênio e peróxido de hidrogênio, dióxido de cloro e peróxido de hidrogênio), PMoQ(PO) (Peróxido de hidrogênio catalisado com molibdênio, quelante e peróxido de hidrogênio pressurizado) e XPMoQ(PO) (Enzima, peróxido de hidrogênio catalisado com molibdênio, quelante e peróxido de hidrogênio pressurizado), com polpas kraft de Eucalyptus spp., buscando uma alvura de 90% ISO. Foram realizados estágios de branqueamento com tratamentos menos usuais tais como: peróxido ácido catalisado com molibdênio (PMo) e xilanase (X). Entre as sequências opcionais ECF, a sequência com dois estágios PMoD/P, mostrou um custo efetivo alto, no entando, sem afetar a qualidade da polpa em relação à sequência tradicional D(EPO)DP e obteve melhor qualidade do efluente também em relação à referência. Porém, a sequência de quatro estágios, XPMoQ(PO), alcançou a alvura desejada utilizando a tecnologia TCF. Essa sequência não teve um custo efetivo baixo, embora tenha produzido uma polpa de qualidade aceitável

Bleaching eucalypt pulps with short sequences

A polpa kraft de Eucalyptus spp., em raz\ue3o do elevado conte\ufado de \ue1cidos hexenur\uf4nicos, \ue9 relativamente f\ue1cil de ser branqueada Dessa forma, estudos t\ueam sido feitos para diminuir o n\ufamero de est\ue1gios de branqueamento na planta, minimizando assim importantes custos do processo. Este estudo teve como objetivo a avalia\ue7\ue3o de sequ\ueancias curtas de branqueamento ECF (Elemental Chlorine Free) e TCF (Totally Chlorine Free): PMoDP (Per\uf3xido de hidrog\ueanio catalisado com molibd\ueanio, seguido por est\ue1gios de di\uf3xido de cloro e per\uf3xido de hidrog\ueanio), PMoD/P (Per\uf3xido de hidrog\ueanio catalisado com molibd\ueanio, di\uf3xido de cloro e per\uf3xido de hidrog\ueanio, sem lavagem entre os dois \ufaltimos est\ue1gios), PMoD(PO) (Per\uf3xido de hidrog\ueanio catalisado com molibd\ueanio, di\uf3xido de cloro e per\uf3xido de hidrog\ueanio pressurizado), D(EPO)DP (Di\uf3xido de cloro, extra\ue7\ue3o oxidativa com oxig\ueanio e per\uf3xido de hidrog\ueanio, di\uf3xido de cloro e per\uf3xido de hidrog\ueanio), PMoQ(PO) (Per\uf3xido de hidrog\ueanio catalisado com molibd\ueanio, quelante e per\uf3xido de hidrog\ueanio pressurizado) e XPMoQ(PO) (Enzima, per\uf3xido de hidrog\ueanio catalisado com molibd\ueanio, quelante e per\uf3xido de hidrog\ueanio pressurizado), com polpas kraft de Eucalyptus spp., buscando uma alvura de 90% ISO. Foram realizados est\ue1gios de branqueamento com tratamentos menos usuais tais como: per\uf3xido \ue1cido catalisado com molibd\ueanio (PMo) e xilanase (X). Entre as sequ\ueancias opcionais ECF, a sequ\ueancia com dois est\ue1gios PMoD/P, mostrou um custo efetivo alto, no entando, sem afetar a qualidade da polpa em rela\ue7\ue3o \ue0 sequ\ueancia tradicional D(EPO)DP e obteve melhor qualidade do efluente tamb\ue9m em rela\ue7\ue3o \ue0 refer\ueancia. Por\ue9m, a sequ\ueancia de quatro est\ue1gios, XPMoQ(PO), alcan\ue7ou a alvura desejada utilizando a tecnologia TCF. Essa sequ\ueancia n\ue3o teve um custo efetivo baixo, embora tenha produzido uma polpa de qualidade aceit\ue1vel.Eucalyptus spp kraft pulp, due to its high content of hexenuronic acids, is quite easy to bleach. Therefore, investigations have been made attempting to decrease the number of stages in the bleaching process in order to minimize capital costs. This study focused on the evaluation of short ECF (Elemental Chlorine Free) and TCF (Totally Chlorine Free) sequences for bleaching oxygen delignified Eucalyptus spp. kraft pulp to 90% ISO brightness: PMoDP (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide), PMoD/P (Molybdenum catalyzed acid peroxide, chlorine dioxide and hydrogen peroxide, without washing) PMoD(PO) (Molybdenum catalyzed acid peroxide, chlorine dioxide and pressurized peroxide), D(EPO)DP (chlorine dioxide, extraction oxidative with oxygen and peroxide, chlorine dioxide and hydrogen peroxide), PMoQ(PO) (Molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide), and XPMoQ(PO) (Enzyme, molybdenum catalyzed acid peroxide, DTPA and pressurized peroxide). Uncommon pulp treatments, such as molybdenum catalyzed acid peroxide (PMo) and xylanase (X) bleaching stages, were used. Among the ECF alternatives, the two-stage PMoD/P sequence proved highly cost-effective without affecting pulp quality in relation to the traditional D(EPO)DP sequence and produced better quality effluent in relation to the reference. However, a four stage sequence, XPMoQ(PO), was required to achieve full brightness using the TCF technology. This sequence was highly cost-effective although it only produced pulp of acceptable quality

Bio-based films from wheat bran feruloylated arabinoxylan: effect of extraction technique, acetylation and feruloylation

This study demonstrates the potential of feruloylated arabinoxylan (AX) from wheat bran for the preparation of bioactive barrier films with antioxidant properties. We have comprehensively evaluated the influence of the structural features and chemical acetylation of feruloylated AX extracted by subcritical water on their film properties, in comparison with alkaline extracted AX and a reference wheat endosperm AX. The degree of substitution (DS) of AX had a large influence on film formation, higher DS yielded better thermal and mechanical properties. The barrier properties of AX films were significantly enhanced by external plasticization by sorbitol. Chemical acetylation significantly improved the thermal stability but not the mechanical or barrier properties of the films. The presence of bound ferulic acid in feruloylated AX films resulted in higher antioxidant activity compared to external addition of free ferulic acid, which demonstrates their potential use in active packaging applications for the preservation of oxygen-sensitive foodstuff.Peer reviewe