145 resultados para PULP
Resumo:
In the current study, an alternative method has been proposed for simultaneous analysis of palmitic, stearic, oleic, linoleic, and linolenic acids by capillary zone electrophoresis (CZE) using indirect detection. The background electrolyte (BGE) used for the analysis of these fatty acids (FAs) consisted of 15.0 mmol L−1 NaH2PO4/Na2HPO4 at pH 6.86, 4.0 mmol L−1 SDBS, 8.3 mmol L−1 Brij 35, 45% v/v acetonitrile (can), and 2.1% n-octanol. The FAs quantification of FAs was performed using a response factor approach, which provided a high analytical throughput for the real sample. The CZE method, which was applied successfully for the analysis of pequi pulp, has advantages such as short analysis time, absence of lipid fraction extraction and derivatization steps, and no significant difference in the 95% confidence intervals for FA quantification results, compared to the gas chromatography official method (AOCS Ce 1h-05).
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Laccase from Aspergillus sp was immobilized on glutaraldehyde-activated chitosan beads. A comparative study between free and immobilized laccase was conducted and the potential of the resulting immobilized derivative in the biodegradation of pulp and paper mill effluent was evaluated. The immobilized laccase is more resistant to various denaturing conditions, which allows for the reduction of 65% of the phenols (total and low molecular weight) and loss of 60% of total color in the effluent. These results show the potential of the immobilized laccase in the biodegradation of phenols, the chemical agents responsible for the high toxicity of the effluent generated in cellulose pulp industries.
Resumo:
Validation of a rapid method for the determination of ascorbic, citric, fumaric and tartaric acids in stored pulp fruit and its application as a quality parameter was performed. The validation parameters showed that for the four evaluated acids, the method presented low limits of detection (LOD) and quantification (LOQ), indicating good precision and accuracy, thus representing an important tool for quality assessment of stored fruit pulp. The results showed that the concentration of organic acids generally decreased with longer storage time in the fruit pulp under study. Amongst all the organic acids under investigation, ascorbic proved the least stable.
Resumo:
Bleached eucalypt kraft pulps are widely used in print and writing (P&W) and tissue paper manufacture. Among the quality requirements of pulp for these papers, xylan content has been controversial. The objective of this study was to evaluate the influence of xylan content on bleachability, hygroscopic, physic-mechanical and optical properties of the pulp. In this study industrial unbleached eucalyptus kraft pulp (15.6% xylans) treated with different NaOH loads to change its xylan content was used. Subsequently, pulps were bleached by the ODHT(EP)D sequence to achieve 90% ISO of brightness, then refined and submitted to hygroscopic, physicomechanical and optical tests. NaOH treatments decreased the xylan content to 14.5-5.9% using NaOH loads of 10-70 g L-1. Pulp bleachability was not significantly affected by xylan content decrease. The decrease in xylan content negatively affected the water retention value and Klemm capillarity of the pulp, while water absorption capacity was positively affected. Tensile and tear index were negatively influenced by the reduction in xylan content, whereas bulk and light scattering coefficient increased.
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The development of a large number of postharvest diseases is closely associated with fruit ripeness. Environmental conditions may affect both the pathogen development and the fruit ripening rate. The aim of this study was to determine the most favorable temperature and wetness duration to the development of anthracnose in guava fruits. Cultivars 'Kumagai' (white pulp) and 'Pedro Sato' (red pulp) were inoculated with a conidial suspension of Colletotrichum gloeosporioides and C. acutatum and incubated at constant temperature ranging from 10 to 35ºC and wetness duration of 6 and 24 hours. Disease severity and incidence were evaluated at every two days during 12 days. No infection occurred at 10 and 35ºC, regardless of the wetness duration. The optimum conditions for fruit infection were 26 and 27ºC for 'Kumagai' and 25 and 26ºC for 'Pedro Sato', adopting 24 hours of wetness. In general, the disease development in 'Kumagai' cultivar was more affected by the wetness period, compared to 'Pedro Sato'. Disease severity for 'Kumagai' fruits was maximal between 25 and 30ºC , depending on the Colletotrichum species. Regarding 'Pedro Sato', the mean diameter of lesions was greater in fruits stored at 20, 25 and 30ºC , compared to 'Kumagai' cultivar, depending on the wetness period and the species. The incubation period (between 6 and 7 days) and the latent period (between 8 and 10 days) were minimal at 30ºC. The data generated in this study will be useful either for the development of a disease warning system or for the increase in the shelf life of guavas in the postharvest.
Resumo:
O presente estudo teve como objetivo avaliar a aplicabilidade do modelo de Clutter em povoamentos desbastados de eucalipto. Esta pesquisa foi desenvolvida com dados da empresa Copener Florestal Ltda., atualmente Bahia Pulp, no Município de Alagoinhas, BA. Os dados utilizados fazem parte de um experimento de desbaste implantado em povoamentos de eucalipto, empregando-se o esquema de blocos casualizados constituídos de quatro tratamentos e repetidos em três locais diferentes, perfazendo 48 parcelas com área média de 2.600 m² cada uma. As parcelas foram medidas aos 27, 40, 50, 58, 61 e 76 meses de idade, e aos 58 meses realizou-se o desbaste. Para ajuste do modelo, foi empregado o sistema de equações simultâneas, que utiliza informações do povoamento referentes a área basal, volume, idade e índice de local. A partir do ajuste do modelo, elaborou-se uma tabela de produção de densidade variável e determinou-se a idade técnica de corte em diferentes capacidades produtivas. Realizaram-se simulações na tabela de produção de regimes de desbaste. Concluiu-se que o modelo de Clutter foi eficiente para predizer a produção atual e futura dos povoamentos desbastados de eucalipto, mostrando-se útil na análise de alternativas de manejo, como a determinação da idade técnica de desbaste, de diferentes índices de local e regimes de desbaste.
Resumo:
Este estudo teve como objetivo comparar a eficiência dos métodos da curva-guia, equação das diferenças e predição de parâmetros para construir curvas de índices de local em povoamentos de eucalipto desbastados. Os dados utilizados foram provenientes de um experimento de desbastes pertencente à empresa Copener Florestal, atualmente Bahia Pulp, BA. Para ajuste dos modelos, utilizaram-se dados de sete remedições (27, 40, 50, 61, 76, 87 e 101 meses) de 48 parcelas, com área média de 2.600 m². Na avaliação individual dos métodos, analisaram-se os coeficientes de determinação, de correlação e erros médios porcentuais, bem como análises gráficas das curvas de índices de local. Para testar a identidade entre os métodos, empregou-se o teste de Leite e Oliveira (2002). Para efetuar o teste, o método da curva-guia foi escolhido como método-padrão e comparado aos outros dois métodos alternativos. Na análise individual, os três métodos se enquadraram no critério adotado para avaliação da eficiência para construir as curvas de índices de local, porém o método da curva-guia foi o que apresentou melhor ajuste. A partir dos resultados do teste de identidade de modelos, constatou-se que as estimativas de índices de local, obtidas pelos métodos alternativos, diferiram estatisticamente do método-padrão, ou seja, não se confirmou a identidade entre os métodos testados. Dessa forma, o método da curva-guia foi considerado o mais adequado para construção das curvas de índices de local de povoamentos de eucalipto submetidos a desbaste.
Resumo:
The present work aimed to characterize and identify QTLs for wood quality and growth traits in E. grandis x E. urophylla hybrids. For this purpose a RAPD linkage map was developed for the hybrids (LOD=3 and r=0.40) containing 52 markers and 12 linkage groups. Traits related to wood quality and growth were evaluated in the QTL analyses. QTL analyses were performed using chi-square tests, single-marker, interval mapping and composite interval mapping analyses. All approaches led to the identification of similar QTLs associated with wood density, cellulose pulp yield and percentage of extractives, which were detected and confirmed by both the interval mapping and composite interval mapping methodologies. Some QTLs regions were confirmed only by the composite interval mapping methodology: percentage of soluble lignin, percentage of insoluble lignin, CBH and total height. Overlapping QTLs regions were detected, and these, can be the result of major genes involved in the regulation and control of the growth traits by epistatic interactions. In order to evaluate the effect of early selection using RAPD molecular data, molecular markers adjacent to QTLs were used genotype selection. The analysis of selection differential values suggests that for all the traits the phenotypic selection at seven years should generate larger genetic gains than early selection assisted by molecular markers and the combination of the strategies should elevate the selection efficiency.
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Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.
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Eucalyptus stands in the setting of worldwide forestry due to its adaptability, rapid growth, production of high-quality and low cost of wood pulp fibers. The eucalyptus convetional breeding is impaired mainlly by the long life cycle making the genetic transformation systems an important tool for this purpose. However, this system requires in vitro eficient protocols for plant induction, regeneration and seletion, that allow to obtain transgenic plants from the transformed cell groups. The aim of this work was to evaluate the callus formation and to optimize the leaves and callus genetic transformation protocol by using the Agrobacterium tumefaciens system. Concerning callus formation, two different culture media were evaluated: MS medium supplemented with auxin, cytokinin (M1) and the MS medium with reduced nitrogen concentration and supplemented with auxin, cytokinin coconut water (M2). To establish the leave genetic transformation, those were exposed to agrobiolistics technique (gene gun), to tissue injury, and A. tumesfasciens EHA 105 contening the vetor pCambia 3301 (35S::GUS::NOS), for gene transference and to establish the callus transformation thoses were exposed only to A. tumefasciens. For both experiments, the influence of different infection periods was evaluated. The M2 medium provided the best values for callus sizea and fresh and dry weight. The leaves genetic transformation using the agrobiolistics technique was effective, the gus gene transient expression could be observed. No significant differences were obtained in the infection periods (4, 6 and 8 minutes). The callus genetic transformation with A. tumefaciens also promotend the gus gene transient expression on the callus co-cultiveted for 15 e 30 minutes. The transformed callus was transfered to a regeneration and selection medium and transformed plants were obtained.
Resumo:
ABSTRACT One of the fastest growing sectors in the domestic industry is the forestry, which has contributed significantly to economic development, job creation, income taxes, putting Brazil in a prominent position in the world market. This paper analyzes the evolution of the technological intensity of 12 main products exported by the sector, from 2000 to 2011. For that, utilizes an indicator called PRODY, which allows classifying different products according to their technological intensity or income content and considers the GDP per capita of exporting countries of each product, weighted by its revealed comparative advantage. It can be seen by the results, a continuous growth in all products' technology indicators and their decomposition into income effects, comparative advantage and joint effects, allowed to verify the main causes of this growth. Products with lower PRODY values are those that presented a higher evolution during the period studied. Products of higher processing, and those from pulp and paper industry, had greater technological advances, thanks to a joint effect, while the ones of lower processing, had a technological improvement due to the increase in GDP per capita in exporting countries. Sawn wood was the standout product, being the only one who proved to be dependent of comparative advantage effect, confirming that this industry has been reinventing itself and incorporating, in fact, more technology. This study revealed the importance of technological intensification to generate comparative advantage and be able to stand against international competition.
Resumo:
In this study the rheological behavior in different temperatures (0; 6; 18 e 24 ºC) and physicochemical parameters of integral annona (Annona squamosa) pulp and the annona pulp with milk in different percentages pulp/milk (75g of annona pulp/25g of milk, 50g of annona pulp/50g of milk, 25g of annona pulp/75g of milk) have been availed, in order to verify the effect of temperature and pulp concentration in the rheological behavior of these beverages. To obtain the rheological parameters a concentric cylinder rheometer has been used and the rheograms were analyzed using the Ostwald-de-Wael (power Law) and Herschel-Bulkley models. The physicochemical parameters (sugars, pH, ash, acidity and soluble solids) were determined in order to establish correlations with the rheological behavior. Finally, the best results had been obtained using the Herschel-Bulkley model; the low values for the behavior index (n <1) obtained confirm the pseudoplastic behavior of all samples.
Resumo:
The vibration during transportation is one of the main causes of fruit damage. The actual methodologies used for damage evaluation in fruits seem to be subjective, since most of them are based on visual evaluation. In this study the effect of vibration, for one and two hours, on polyphenoloxidase (PPO) activity in peach pulp was investigated. The relation among PPO activity variation, postharvest time and resting time were also considered. Results showed that vibration affects PPO activity. However, it was not possible to correlate PPO activity variation and vibration.
Resumo:
Irrigation is a practice widely used in fruit production in the Brazilian Northeast region, including in the papaya crop in order to increase their productivity. For the purpose of knowing the productive potential of papaya hybrid irrigated, an experiment was carried out in order to evaluate the performance of a papaya hybrid under different irrigations depths. Four irrigation depths (50, 75, 100 and 125% of ETo) were tested and the reference evapotranspiration was calculated by the Penman-Monteith model. The hybrid papaya used was UENF/Caliman 01, which was planted in single rows, spaced 4 x 2m from each other, and irrigated by dripping. The experimental design in randomized blocks was used with six replications and three plants per plot. The following variables were evaluated: transversal diameter, longitudinal diameter, pulp thickness, external and internal appearances, soluble solids, titratable acidity, pulp pH and soluble solids/titratable acidity relation. The higher transversal and longitudinal diameters of the fruit were obtained applying an irrigation depth of about 108% of evapotranspiration. The UENF/Caliman 01 hybrid can be cultivated in the semiarid region of the State of Paraiba, Brazil, with replacement rate of 100% ETo, without compromising the quality of the fruits.
Resumo:
ABSTRACT Precision agriculture adoption in Brazilian apple orchards is still incipient. This study aimed at evaluating the spatial variability of certain soil properties as soil density, soil penetration resistance, electrical conductivity, yield, and fruit quality in an apple orchard through digital mapping, as well as assessing the correlation between these factors by means of geostatistics, establishing management zones. Forty representative points were set within 2.5 hectares of apple orchard, wherein soil samples were collected and analyzed, besides measurements of fruit quality (Brix degree, size or diameter, pulp firmness and color) to generate an overall index quality. We concluded that the fruit quality indexes, when isolated, did not show strong spatial dependence, unlike the index of fruit quality (FQI), derived from a combination of these parameters, allowing orchard planning according to management zones based on quality.