INFLUÊNCIA DA IDADE DE CORTE DE CLONES DE Eucalyptus grandis E HÍBRIDOS DE Eucalyptus grandis x Eucalyptus urophylla NA COMPOSIÇÃO QUÍMICA DA MADEIRA E POLPAÇÃO KRAFT

The recent efforts on the quality of the wood used in pulp and paper mills has focused in many points, among them the influence of the raw material chemical characteristics in the production process and final product quality. Considering the current demand for younger trees, the effect of the wood harvesting age in the chemical composition and in the process variables becomes a very important fact for the industries of this sector. So, the objective of this study was to characterize Brazilian eucalypt clones, Eucalyptus grandis and Eucalyptus urograndis, both in different harvesting ages (1 to 8 years-old), for their chemical composition and kraft pulping parameters. Both chemical compositions of wood samples showed significant statistical variations due to the alteration of their harvesting ages. The glucan content, as well as cellulose content, basic density, and extractives tended to rise with the increase of harvesting age; while xylan and the other carbohydrate contents that compose the hemicelluloses tended to decline with the increase of the harvesting age, as well as uronic acids, acetyl groups, lignin, ashes, and S:G ratio. The 5 year-old wood samples showed the greatest pulping yield results for kappa number 17, and the yield at kappa number 17 showed strong correlation with glucan content.Os recentes esforços na melhoria da qualidade da madeira para o abastecimento das fábricas de celulose e papel têm focado em muitos pontos, dentre estes, a influência das características químicas da matéria-prima no processo produtivo e na qualidade do produto final. Considerando a atual demanda por árvores mais jovens, o efeito da idade de corte da madeira na composição química e nas variáveis de processo, torna-se uma questão importante para as indústrias do setor. Em função disto, o objetivo do presente estudo foi caracterizar clones de eucalipto, Eucalyptus grandis e híbridos Eucalyptus urograndis, ambos em diferentes idades de corte (1 a 8 anos) quanto às suas composições químicas e parâmetros de polpação kraft. Ambas as composições químicas das madeiras mostraram variações estatísticas significativas devido às suas diferentes idades de corte. O teor de glicanas, assim como o teor de celulose, densidade básica e extrativos, aumentaram com o aumento da idade de corte das árvores, enquanto o teor de xilanas e demais carboidratos que compõem as hemicelulose, tenderam a diminuir com o aumento da idade de corte, assim como os ácidos urônicos, grupos acetila, lignina, cinzas e relação S:G da lignina da madeira. As amostras com 5 anos de idade mostraram o melhor rendimento na polpação kraft para número kappa 17, e este rendimento (número kappa 17) mostrou forte correlação com o teor de glicanas

Effect of extractives on wood color of heat treated Pinus radiata and Eucalyptus pellita

Heat treatment can change wood color without any use of environmentally harmful chemicals, and the efficiency of this process depends on the raw material to be treated. The objective of this study was to evaluate the influence of extractives on the color change of Eucalyptus pellita and Pinus radiata wood during heat treatment. The extractives were extracted in cold water and in dichloromethane as well as totally removed and the wood was treated at 170°C and 200°C for three hours under atmospheric pressure and in presence of air for evaluating the lightness (L*), green-red coordinate (a*), blue-yellow coordinate (b*), color saturation (C) and tonality angle (H) values. Pinus radiata wood was more resistantto discoloration by heat treatment. The removal of total and cold water-soluble extractives before heat treatment changed the L* value of Pinus radiata, a* value of Eucalyptus pellita, and b*, C, and H valuesof both species. Removal of extractives soluble in dichloromethane did not affect the color of heat treated wood. Thus, understanding the influence of extractives on heat treated wood can allow adapting the raw material to the process for enhancing the applicability of heat treatment for changing wood color

Impacts of physical and chemical modifications to eucalyptus fibers in a bleached pulp quality

Mundialmente, a indústria de celulose e papel vem sofrendo transformações decorrentes de alterações no cenário de aceleração industrial aliadas à célere emergência de tecnologias e demanda por melhorias na qualidade do produto final. A modificação da fibra de eucalipto é uma alternativa bastante atrativa quando são requeridas melhorias de propriedades do papel produzido, podendo contribuir para a prosperidade da indústria setorial. Neste contexto, o presente trabalho objetiva discorrer no âmbito de modificações físico-químicas e estruturais da fibra de eucalipto com o específico propósito de produzir papéis. Para tal, foram abordadas modificações por tratamento oxidativo (com peróxido de hidrogênio), adsorções poliméricas (xilana e carboximetilcelulose), e tecnologia de plasma atmosférico, através de descarga por barreira dielétrica (DBD). De uma forma geral, os tratamentos aplicados à polpa celulósica (oxidativo e adsorções poliméricas) resultaram na alteração do perfil de grupos funcionais do material fibroso, sendo reportado aumento na faixa de 10-30% no conteúdo de grupos carboxílicos, em função da dose e do tipo de tratamento aplicado. As polpas apresentaram, ainda, desenvolvimento de propriedades de absorção, marcado pelo aumento do índice de retenção de água e pela redução do fenômeno de "hornification" das fibras. Além disso, incremento na refinabilidade foi verificado para as polpas tratadas, havendo significativa redução da demanda energética durante a etapa de refino. Melhorias de propriedades físico-mecânicas e ópticas dospapéis produzidos foram evidenciadas, sendo estas, notadamente, função do desenvolvimento de ligações interfibras, em decorrência dos tratamentos. Já o tratamento de plasma atmosférico, através de DBD, aplicado aos papéis formados à partir da polpa branqueada de eucalipto mostrou-se efetivo no incremento de propriedades de tração à úmido. Além disso, sob condições específicas de instrumentação, a resistência dos papéis à seco também pode ser acrescida. A densidade de carga específica do material fibroso manteve-se inalterada em função do tratamento de DBD aplicado, sendo o aumento de resistência dos papéis atribuído ao desenvolvimento de ligações covalentes cruzadas. Propriedades de absorção/retenção de umidade foram acrescidas, controlando-se a dose do tratamento de DBD e imagens obtidas por análise de microscopia de força atômica demonstraram modificação superficial da fibra, especialmente observação de regularização da superfície. Conclusivamente, os tratamentos estudados, quando aplicados à indústria papeleira, atentando às suas inerentes peculiaridades, podem gerar um produto de qualidade diferenciada e, especialmente, superior ao atualmente produzido.Globally, pulp and paper industry has undergoing transformations due to changes in the industrial acceleration scenario linked to the rapid emergence of technology and demand for improvements in the final product quality. When improvements in paper properties are required modification of eucalyptus fiber is a very attractive alternative, which may contribute to the prosperity of the industry sector. In this context, the present study aims to discuss changes in physical-chemical and structural properties of eucalyptus fiber with the specific purpose of producing papers with improved quality. To this end, changes were addressed by oxidative treatment (hydrogen peroxide), polymers adsorption (xylan and carboxymethylcellulose), and atmospheric plasma technology, using dielectric barrier discharge (DBD). In general, the treatments applied to pulp (oxidative and polymers adsorption) resulted in changes of the functional groups profile of fibrous material, being reported an increase in the range of 10-30% in the content of carboxylic groups, depending on dosage and type of treatment applied. In addition, the pulps presented development of absorption properties, marked by increased rates of water retention value and reduced phenomenon of fiber hornification. Moreover, increase in refinability was observed, with significant reduction in energy demand during this stage. Improvements on physical-mechanical and optical properties were found and are, remarkably, dependent on the development of inter-fibers linkages due to the treatments. Atmospheric plasma treatment, by DBD, when applied to the paper formed from bleached eucalyptus pulp was effective in increasing the wet tensile properties. Moreover, under specific instrumentation conditions, paper dried resistance might also be increased. The specific charge density of the fibrous material remained unchanged when DBD treatment was applied, being the rising in strength assigned to the development of fiber cross-linking. Moisture absorption/retention properties have been added by controlling the dosage of DBD treatment where image analysis obtained by atomic force microscopy demonstrated fiber surface modification, especially observation of surface regularization. Conclusively, the treatments, when applied to the paper industry, paying attention to their inherent peculiarities, can produce products with differentiated quality aspects that are higher than the currently produced.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Composition and antifungal activity of extracts of Chenopodium ambrosioides L.

O óleo essencial, obtido por hidrodestilação (rendimento de 0,3%), e o extrato hexânico, adquirido por maceração (rendimento de 1,1%), de partes aéreas de Chenopodium ambrosioides L., avaliados pela metodologia poison food (0,3; 0,1; 0,05 e 0,3; 0,2; 0,1%; respectivamente), apresentaram atividade antifúngica contra os fitopatógenos Aspergillus flavus, A. glaucus, A. niger, A. ochraceous, Colletotrichum gloesporioides, C. musae, Fusarium oxysporum e F. semitectum. Exímia atividade antifúngica, variando de 70 a 100%, foi observada em concentração de até 0,2 e 0,1%, para o extrato hexânico e o óleo essencial, respectivamente, dependendo do fungo avaliado. Utilizando cromatografia gasosa com detector de ionização em chama (CG/DIC) e cromatografia gasosa acoplada a espectrometria de massas (CG/EM), aliados ao cálculo do índice de retenção de Kováts (KI), estabeleceu-se a composição do extrato e do óleo essencial. No óleo essencial treze compostos foram identificados, correspondendo a 90,22% da sua constituição, sendo os principais: (Z)-ascaridol (61,43%), (E)-ascaridol (18,62%), carvacrol (3,87%), pcimeno (2,05%) e [alfa]-terpineno (0,85%). Os componentes do extrato hexânico são: [alfa]-terpineno (11,24%), p-cymeno (6,05%), álcool benzílico (0,38%), (Z)-ascaridol (53,98%), carvacrol (2,27%), (E)-ascaridol (17,25%), correspondendo a 91,17% da sua constituição. Após fracionamento por cromatografia em camada delgada (CCD) (eluição com diclorometano:acetato de etila, 9:1 v/v), bioensaio utilizando a técnica CCD Bioautografia revelou a fração antifúngica do extrato hexânico e do óleo essencial. Uma única fração ativa foi obtida para ambas as amostras, apresentando coeficiente de retenção (Rf) equivalente a 0,89 e largura longitudinal (Wb) de 5,0 cm, sendo os compostos identificados por análise em CG/DIC, CG/EM e cálculo do KI. A fração ativa do extrato hexânico é composta por (Z)-ascaridol (53,98%), (E)-ascaridol (17,25%), [alfa]-terpineno (11,24%) e p-cimeno (6,05%) e a do óleo essencial constitui-se por pcimeno (25,40%), (Z)-ascaridol (44,35%) e (E)-ascaridol (30,25%). Análise, por CG/DIC, da estabilidade do extrato hexânico e do óleo essencial, após o armazenamento dos mesmos por 90 dias, a 4 e 25 oC, apontou decomposição dos compostos [alfa]-terpineno, p-cimeno, (Z)-ascaridol e (E)-ascaridol nas amostras. As decomposições foram mais acentuadas quando as amostras foram estocadas a 25 oC. A quantificação de ergosterol, principal esteróide constituinte da membrana celular fúngica, por CG/EM, utilizando modo MSI (Monitoramento Seletivo de Íons), em amostras de ração de suínos armazenadas, tratadas com extrato hexânico (0,2%) e óleo essencial (0,1%), apontou a atividade da espécie C. ambrosioides no controle do crescimento fúngico. Frente aos resultados alcançados nota-se o potencial antifúngico do óleo essencial e do extrato hexânico de C. ambrosioides, enfatizando os compostos ascaridol (isômeros Z e E), [alfa]-terpineno e p-cimeno, que, após estudos sistemáticos, são compostos viáveis a comercialização como agentes no controle de fungos de armazenamento.Essential oil obtained by hydrodistillation (yield 0.3%), and hexanic extract, obtained by maceration (yield 1.1%), of the aerial parts of Chenopodium ambrosioides L., evaluated by the poison food methodology (0.3; 0.1; 0.05 and 0.3; 0.2; 0.1%; respectively), presented antifungal activity against the phytopathogens Aspergillus flavus, A. glaucus, A. niger, A. ochraceous, Colletotrichum gloesporioides, C. musae, Fusarium oxysporum and F. semitectum. Excellent antifungal activity, ranging from 70 to 100%, was observed up to a concentration of 0.2 and 0.1%, for the hexanic extract and essential oil, respectively, depending on the fungus evaluated. Using gas chromatography with flame ionization (GC/FID) and gas chromatography coupled to mass spectrometry (GC/MS), combined to calculation of the Kováts index of retention (KI), the hexanic extract and essential oil compositions were established. In the essential oil, 13 compounds were identified, corresponding to 90.22% of its constitution, the major ones being: (Z)-ascaridole (61.43%), (E)-ascaridole (18.62%), carvacrol (3.87%), p-cymene (2.05%) and [alfa]-terpinene (0.85%). The hexanic extract compounds are: [alfa]-terpinene (11.24%), p-cymene (6.05%), benzyl alcohol (0.38%), (Z)-ascaridole (53.98%), carvacrol (2.27%), (E)-ascaridole (17.25%) corresponding to 91.17% of its constitution. Following fractioning by thin layer chromatography (TLC) (elution with dichloromethane: ethyl acetate, 9:1 v/v), a bioassay using TLC Bioautography technique revealed the antifungal fraction of the hexanic extract and essential oil. One single active fraction was obtained for both the samples, presenting retention coefficient (Rf) equivalent to 0.89 and longitudinal width (Wb) of 5.0 cm, with the compounds being identified by analysis in GC/FID, GC/MS and KI calculation. The active fraction of the hexanic extract is composed of (Z)-ascaridole (53.98%), (E)-ascaridole (17.25%), [alfa]-terpinene (11.24%) and p-cymene (6.05%) and that of the essential oil is constituted by p-cymene (25.40%), (Z)-ascaridole (44.35%)and (E)-ascaridole (30.25%). Analysis by GC/FID of hexanic extract and essential oil stability after 90-day storage at 4 and 25 oC, showed decomposition of the compounds [alfa]-terpinene, p-cymene, (Z)-ascaridole and (E)-ascaridole in the samples. Decompositions were greater for the samples stored at 25 oC. Quantification of ergosterol, main sterol constituent of the fungic cellular membrane, by GC/MS, utilizing SIM mode (Selective Ion Monitoring), in stored swine ration treated with hexanic extract (0.2%) and essential oil (0.1%) pointed to activity of the species C. ambrosioides in fungal growth control. The results obtained indicate the antifungal potential of the essential oil and hexanic extract of C. ambrosioides, with emphasis on the compounds ascaridole (Z and E), [alfa]-terpinene and p-cymene, which, after further systematic studies, are commercially viable as storage fungi control agents.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Composition and antifungal activity of the essential oil of the Brazilian Chenopodium ambrosioides L.

The antifungal activity of essential oil (EO) from the Brazilian epazote (Chenopodium ambrosioides L.) was evaluated by the poison food assay at concentrations of 0.3%, 0.1%, and 0.05% with eight postharvest deteriorating fungi (Aspergillus flavus, Aspergillus glaucus, Aspergillus niger, Aspergillus ochraceous, Colletotrichum gloesporioides, Colletotrichum musae, Fusarium oxysporum, and Fusarium semitectum). EO components were tentatively identified by Kováts retention indices (RIs) using gas chromatography and gas chromatography combined with mass spectrometry (GC-MS). Growth of all fungi was completely inhibited at 0.3% concentration, and by 90% to 100% at 0.1% concentration. The following 13 tentatively identified compounds (relative percent) accounted for 90.4% of the total volatile oil: α-terpinene (0.9), p-cymene (2.0), benzyl alcohol (0.3), p-cresol (0.3), p-mentha-1,3,8-triene (0.2), p-cimen-8-ol (0.6), α-terpineol (0.5), (Z)-ascaridole (61.4), piperitone (0.9), carvacrol (3.9), (E)-ascaridole (18.6), (E)-piperitol acetate (0.5), and (Z)-carvyl acetate (0.3). Autobiographic thin layer chromatography of the EO to separate the principal fungitoxic fraction yielded only one fraction that completely inhibited the growth of all test fungi at a concentration of 0.1%. This fraction was characterized by RIs and GC-MS presenting a composition (%) of p-cymene (25.4), (Z)-ascaridole (44.4), and (E)-ascaridole (30.2). The results suggest ascaridoles were the principal fungitoxic components of the EO

Composition, antifungal activity and main fungitoxic components of the essential oil of Mentha piperita L.

Twenty-one components (93.9% of the total chromatographic peak area) were tentatively identified in the essential oil (EO) of Mentha piperita L., based on Kováts retention indices (RIs), a mass spectral database (gas chromatography-mass spectrometry, GC-MS) and visual comparison of the mass spectra of the sample peaks with those of the database. The presence of 15 compounds (corresponding to 90.7% of the total chromatographic peak area) was confirmed by authentic standards. The EO presented a good activity against the following important postharvest deteriorating fungi: Aspergillus flavus, Aspergillus glaucus, Aspergillus niger, Aspergillus ochraceous, Colletotrichum gloesporioides, Colletotrichum musae, Fusarium oxysporum and Fusarium semitectum. At a concentration of 0.2% of the EO, all the fungi were completely inhibited, except for A. glaucus and C. musae which were inhibited 90 and 98%, respectively. TLC-bioautography yielded three subfractions that prevented fungal growth, suggesting the presence of antifungals. Bioassay data of the crude EO were compared with those of the three subfractions. Based on these tests, it was concluded that several fungitoxics were responsible for the antifungal activity of M. piperita, with the principal ones being menthone, neomenthol, menthol and carvone. However, participation of other compounds cannot beruled out. This is the first study in the literature that presents data on the activity of the crude EO against eight important postharvest deteriorating fungi, characterizing the amounts and types of comounds. In addition, also for the first time, the active fractions of the crude EO were isolated, identified and the components quantified. More detailed fungal tests are being conducted to confirm the tentative preliminary antifungal data

INFLU\ucaNCIA DA IDADE DE CORTE DE CLONES DE Eucalyptus grandis E H\ucdBRIDOS DE Eucalyptus grandis x Eucalyptus urophylla NA COMPOSI\uc7\uc3O QU\ucdMICA DA MADEIRA E POLPA\uc7\uc3O KRAFT

The recent efforts on the quality of the wood used in pulp and paper mills has focused in many points, among them the influence of the raw material chemical characteristics in the production process and final product quality. Considering the current demand for younger trees, the effect of the wood harvesting age in the chemical composition and in the process variables becomes a very important fact for the industries of this sector. So, the objective of this study was to characterize Brazilian eucalypt clones, Eucalyptus grandis and Eucalyptus urograndis, both in different harvesting ages (1 to 8 years-old), for their chemical composition and kraft pulping parameters. Both chemical compositions of wood samples showed significant statistical variations due to the alteration of their harvesting ages. The glucan content, as well as cellulose content, basic density, and extractives tended to rise with the increase of harvesting age; while xylan and the other carbohydrate contents that compose the hemicelluloses tended to decline with the increase of the harvesting age, as well as uronic acids, acetyl groups, lignin, ashes, and S:G ratio. The 5 year-old wood samples showed the greatest pulping yield results for kappa number 17, and the yield at kappa number 17 showed strong correlation with glucan content.Os recentes esfor\ue7os na melhoria da qualidade da madeira para o abastecimento das f\ue1bricas de celulose e papel t\ueam focado em muitos pontos, dentre estes, a influ\ueancia das caracter\uedsticas qu\uedmicas da mat\ue9ria-prima no processo produtivo e na qualidade do produto final. Considerando a atual demanda por \ue1rvores mais jovens, o efeito da idade de corte da madeira na composi\ue7\ue3o qu\uedmica e nas vari\ue1veis de processo, torna-se uma quest\ue3o importante para as ind\ufastrias do setor. Em fun\ue7\ue3o disto, o objetivo do presente estudo foi caracterizar clones de eucalipto, Eucalyptus grandis e h\uedbridos Eucalyptus urograndis, ambos em diferentes idades de corte (1 a 8 anos) quanto \ue0s suas composi\ue7\uf5es qu\uedmicas e par\ue2metros de polpa\ue7\ue3o kraft. Ambas as composi\ue7\uf5es qu\uedmicas das madeiras mostraram varia\ue7\uf5es estat\uedsticas significativas devido \ue0s suas diferentes idades de corte. O teor de glicanas, assim como o teor de celulose, densidade b\ue1sica e extrativos, aumentaram com o aumento da idade de corte das \ue1rvores, enquanto o teor de xilanas e demais carboidratos que comp\uf5em as hemicelulose, tenderam a diminuir com o aumento da idade de corte, assim como os \ue1cidos ur\uf4nicos, grupos acetila, lignina, cinzas e rela\ue7\ue3o S:G da lignina da madeira. As amostras com 5 anos de idade mostraram o melhor rendimento na polpa\ue7\ue3o kraft para n\ufamero kappa 17, e este rendimento (n\ufamero kappa 17) mostrou forte correla\ue7\ue3o com o teor de glicanas

Effect of extractives on wood color of heat treated Pinus radiata and Eucalyptus pellita

Heat treatment can change wood color without any use of environmentally harmful chemicals, and the efficiency of this process depends on the raw material to be treated. The objective of this study was to evaluate the influence of extractives on the color change of Eucalyptus pellita and Pinus radiata wood during heat treatment. The extractives were extracted in cold water and in dichloromethane as well as totally removed and the wood was treated at 170°C and 200°C for three hours under atmospheric pressure and in presence of air for evaluating the lightness (L*), green-red coordinate (a*), blue-yellow coordinate (b*), color saturation (C) and tonality angle (H) values. Pinus radiata wood was more resistantto discoloration by heat treatment. The removal of total and cold water-soluble extractives before heat treatment changed the L* value of Pinus radiata, a* value of Eucalyptus pellita, and b*, C, and H valuesof both species. Removal of extractives soluble in dichloromethane did not affect the color of heat treated wood. Thus, understanding the influence of extractives on heat treated wood can allow adapting the raw material to the process for enhancing the applicability of heat treatment for changing wood color