Changes in chemical characteristics of bamboo (Phyllostachys pubescens) components during steam explosion

Chemical changes in cell wall components of bamboo internode during steam explosion process were analyzed to investigate self-binding mechanism of binderless board from steam-exploded pulp. More than 30% of xylose on initial mass, which is a major hydrolyzate of bamboo hemicelluloses, was lost after steam explosion treatment. Bamboo lignin is characterized by the presence of ester- and/or ether-linked p-coumaric acid to lignin. The content of phenolic hydroxyl groups of lignin isolated from steam-exploded pulp was characterized 2.3 times higher than those of the extract-free bamboo internode due to the cleavage of β-O-4 linkages. Alkaline nitrobenzene oxidation of the bamboo lignin gave vanillin, syringaldehyde and p-hydroxybenzaldehyde as major products. The content of p-hydroxybenzaldehyde decreased after steam explosion treatment, indicating the cleavage of ester- and/or ether-linked p-coumaric acid. The total yield of erythronic and threonic acids in ozonation products of the extract-free bamboo internode lignin was 268 mmol (200 g lignin)⁻¹, while those of lignins in the steam-exploded pulp and powdery fraction were 96 and 129 mmol (200 g lignin)⁻¹, respectively, suggesting the significant cleavage of β-O-4 linkages during steam explosion treatment. The cleavage of β-O-4 linkages was also confirmed by ¹H- and ¹³C-NMR spectroscopic observations.     

Micromorphology and topochemistry of extractives in Scots pine and Norway spruce thermomechanical pulps: a cytochemical approach

Due to the increasing demand for Norway spruce as prime raw material for high-yield pulping, recent interest has focused on Scots pine as an alternative. However, the intrinsic properties of Scots pine, particularly the high amounts of extractives and the fiber properties, have been considered a disadvantage for thermomechanical pulping. A study was therefore conducted on the variations in the spatial distribution and redistribution of lipophilic extractives in spruce and pine wood and thermomechanical pulp (TMP) using cytochemical staining methods and chemical analysis. Chemical analyses showed chips from pine thinnings and sawmill slabs to contain three to five and two to three times, respectively, more extractives than found in spruce; in particular, the amount of triglycerides differed significantly. Results from staining techniques on the abundance and distribution of extractives (i.e., fats) between pine and spruce correlated with amounts detected by Fourier transform infrared spectroscopy and gel permeation chromatography. Cytochemical observations revealed information pertaining to species-specific distribution and redistribution of extractives among TMP fines and fibers and indicated the presence of a molecular film of extractives. Results indicate that the high concentrations of extractives in pine ray parenchyma are released during TMP processing and are redistributed onto the surfaces of the pulps, negatively affecting energy usage during primary refining.     

世界木材制浆造纸工业技术发展趋势

林业是制浆造纸工业的基础，纸和纸板是高效益的林产品之一。随着科学技术的进步，制浆造纸工业已成为高技术工业。本文介绍了制浆造纸的原料问题和４种主要的制浆方法，并对制浆造纸工业技术的发展趋势进行了预测。     

Solid-state13C-NMR analysis of size components in handsheets prepared by fatty acid soap size-alum systems

The mechanism of paper sizing in fatty acid soap size-alum systems was studied by structural analyses of the size components in handsheets prepared with¹³C-labeled fatty acid soap size. Patterns of sizing performance and aluminum content of the handsheets were similar to those for the rosin soap size-alum sizing systems, although the patterns of calcium content were different. Solid-state¹³C-nuclear magnetic resonance analysis of the handsheets revealed that fatty acid calcium salt was the predominant size component in the handsheets prepared using tap water. This calcium salt is formed from the fatty acid soap size (fatty acid potassium salt) by ion exchange with calcium ion in pulp suspensions and retained on pulp fibers through aluminum compounds originating from alum added. On the other hand, when deionized water was used, free fatty acid was the major component in the handsheets. Fatty acid aluminum salt was present as a minor component in the handsheets prepared in both tap water and deionized water systems. Therefore, all size components (i.e., fatty acid calcium salt, free fatty acid, fatty acid aluminum salt) seem to contribute to the appearance of sizing features.This research was presented in part at the 64th Pulp and Paper Research Conference of Japan TAPPI, Tokyo, June 1997     

Composition and bioactivity of secretion from Stauronematus compressicornis (Fabricius)

We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis (Fabricius). A leaf-sandwich method was applied to test the bioactivity of the secretion. Coomassie brilliant blue, gas chroma-tography (GC) and other methods were used to analyze and carry out protein assays, amino acid analyses, fatty acid and cholesterol detection of the secretion. Results show that the secretion had a significant antifeeding effect on 4th instar larvae of the armyworm (Pseudaletia separata Walker). Dissolved in 0.27 mol·L^–1 HCl, 0.1 mol·L^–1 NaOH and 0.05 mol·L^–1 Na₂HPO₄ separately, the secre-tions had antifeeding rates ranging from 22.7% to 49.6%. Meanwhile, the weights of the secretion-treated insects were significantly lower than those of the control. Biochemical detection showed that the proteins contained in the secretion were composed of 16 amino acids. The secretion also contained small amounts of cholesterol and fatty acids, which included lauric acid, myristic acid, myristoleic acid, seventeen carbonic acids and oleic acid.     

Lignin characterization of triploid clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones of Populus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin (MWL), lignin carbohydrate complex (LCC) and the residual lignin from kraft pulp (KP) and sulfite pulp (SP) were isolated and analyzed by Fourier transform infrared (FTIR) spectrum and ¹³C nuclear magnetic resonance (NMR). The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P. tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio of A 1270 cm⁻¹ to A1226 cm⁻¹ is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P. tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm⁻¹, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.     

Development and application of a capillary electrophoresis method for the determination of ellagic acid in E. globulus wood and in filtrates from E. globulus kraft pulp

A capillary zone electrophoresis (CZE) method for simple and rapid determination of ellagic acid (EA) in Eucalyptus globulus wood and in the filtrate from unbleached kraft pulp has been developed. This is the first application of CZE for the detection of EA in industrial streams from cellulosic pulp production. The EA determinations in wood extractives and in pulp filtrates were succeeded only after sample acidification. This new CZE analytical procedure allowed reliable determinations of EA in E. globulus wood (1.1 ± 0.6 g kg^?1 of dry wood) and in the filtrates from unbleached kraft pulp (98 ± 0.7 mg L^?1). Gas chromatography–mass spectrometry was used as a reference method for the quantification of EA in industrial samples.     

Acetic acid pulping of wheat straw under atmospheric pressure

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw was made of the chemical composition, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and fractionated into pulp (cellulose), acetic acid lignin, and sugars (monosaccharides from hemicellulose), making it easy to utilize them. It was found that among the pulping conditions the dosage of H₂SO₄ as catalyst was the most notable, and the extent and rate of delignification could be controlled by varying the amount of the catalyst. The results also showed that acetic acid pulp was quite different from soda-AQ pulp. About 70% of the ash or 90% of the silica in wheat straw were kept in AcOH pulp. The ash might function as filler and be beneficial to the printability of paper. It was known that many epidermal cells existed in AcOH pulp in bundles or in single cells. These ash-rich nonfiber cells seemed to hinder the bonding between fibers. AcOH pulp had lower strength than soda-AQ pulp, which might result mainly from the chemical damage of fibers caused by acid, not from the depolymerization of cellulose.Part of this paper was presented at the 65th Pulp and Paper Research Conference of Japan TAPPI, Tokyo, June 1998     

-TD引发体系下TMP与MMA接枝工艺的研究

研究了Fe^2＋-H2O2-二氧化硫脲（TD）引发体系下热磨机械浆（TMP）浆料与甲基丙烯酸甲酯（MMA）的接枝共聚工艺。分析了在该引发体系下各反应条件对接枝率、接枝效率和单体转化率的影响。结果表明，TD的加入能有效地使接枝共聚得以顺利进行；适当提高温度，增加单体浓度，控制合适的TD用量都能提高接枝率和接枝效率，并能在较短的时间成功接枝；接枝率一般维持在80％以上，适宜条件下能达到91％。     

山核桃种仁蛋白质及氨基酸成分含量的变异分析

以3个地区50个山核桃初选优树为试样,研究了地域分布和单株在种仁粗蛋白、氨基酸组成和氨基酸含量诸性状上的差异.结果表明:(1)临安、淳安、安吉三地区山核桃种仁粗蛋白含量平均值为113.0 mg·g-1,变异系数为9.73%;方差分析表明地域分布对粗蛋白含量的影响达到显著水平,具中等广义遗传力(H2=0.342 9).(2)山核桃种仁富含17种氨基酸,其中含人体8种必需氨基酸中的7种,必需氨基酸占氨基酸总量的33.07%,并且比例是稳定的,变异系数仅1.63%;而氨基酸总量以及7种必需氨基酸的含量变异系数较大,均超过16%,尤以甲硫氨酸为最,达到64.92%.     

Factors influencing retention behavior of aluminum compounds on handsheets

Handsheets were prepared with aluminum sulfate under various conditions of pulp suspension, and factors influencing retention behavior of aluminum components on the handsheets were studied on the basis of their aluminum contents. When deionized water was used in the handsheet-making process, aluminum contents in the handsheets had a plateau level of 0.7mg/g in the range of 1%–8% Al₂(SO₄)₃ addition levels on dry weight of pulp. On the other hand, when tap water was used aluminum contents increased up to 5.6 mg/g, increasing the Al₂(SO₄)₃ addition levels to 8%. The high aluminum contents in the handsheets are explained in terms of pH and the presence of calcium ions from the tap water used. Cationic aluminum species, which are formed from aluminum sulfate added to pulp suspensions, are primarily adsorbed on pulp fibers by electrostatic interactions with carboxyl groups in the pulp, competing with OH^– ions in water. These aluminum components, once adsorbed on pulp fibers by ionic interactions, are not removed from the fibers by extending the stirring time of the pulp suspensions.This research was presented in part at the 48th annual meeting of the Japan Wood Research Society in Shizuoka, April 1998     

Growth response and nitrogen use physiology of Fraser fir (Abies fraseri), red pine (Pinus resinosa), and hybrid poplar under amino acid nutrition

Plants can assimilate amino acids from soils. This has been demonstrated in controlled environments and soils of various forest ecosystems. However, the role of root-absorbed amino acids in plant nitrogen nutrition is still poorly understood. We investigated the agroecological performance and nutrient use physiology of two conifers (Abies fraseri and Pinus resinosa) and one hardwood species (hybrid poplar) under amino acid fertilization. Arginine fertilizer (arGrow^® Complete) was applied at varying rates (0, 56, 112, 224, and 336 kg N/ha) and compared to an inorganic control treatment (ammonium sulfate 112 kg N/ha). Parameters monitored included tree growth response, foliar nitrogen concentration, and inorganic nitrogen leaching below the rootzone. Results obtained indicate a significant growth and foliar nitrogen response to amino acid treatments, with increasing amino acid application leading to greater growth and foliar nitrogen. However, rates two to three times higher than that of the inorganic control were necessary to provide similar growth and foliar nitrogen responses. These observations were suggested to be due to competition with soil microbes for organic nitrogen, growth inhibition due to the presence of large concentrations of amino acids, or adsorption to cation exchange sites. Amino acid applications did not increase the leaching of inorganic nitrogen due either to the binding of positively charged arginine cations to exchange sites or rapid mineralization followed by plant assimilation. Mineral nitrogen collected in leachate samples increased with the application rate suggesting at least some mineralization in high amino acid application rates. We conclude that growth response and nitrogen use physiology of these species when treated with arginine are largely controlled by soil processes including microbial competition and adsorption. Further studies are being conducted to confirm these hypotheses.     

Decontamination of Cs from Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) via kraft cooking

To investigate the possibility of decontaminating ¹³⁷Cs-contaminated Cryptomeria japonica wood, kraft pulping was conducted and the Cs behavior in the reaction process was examined. ¹³³Cs-treated or ¹³⁷Cs-contaminated bark, sapwood, and heartwood chips of Cryptomeria japonica were digested using an aqueous solution of NaOH and Na₂S. The pulp was washed with ultrapure water and filtered, after which the filtrate (black liquor) was collected. The black liquor was acidified to separate the supernatant and precipitation. The Cs (¹³³Cs and ¹³⁷Cs) concentrations in the chip and reaction products were measured. As for wood samples, the majority of Cs was present in black liquor, while only a minor amount of Cs was retained in the pulp (<1%). In the case of bark, although the majority of Cs was present in the black liquor, the proportion of Cs in the pulp was much higher than that in the wood pulp. In addition, the Cs in the precipitation of the bark was higher than that in the wood, possibly because the Cs in the bark was combined with some components, which is insoluble in alkaline solution. Our results suggest that ¹³⁷Cs-contaminated Cryptomeria japonica wood can be used in the pulp and paper industries.     

Studies on interactions between aluminum compounds and cellulosic fibers in water by means of27Al-NMR

Interactions between pulp fibers and aluminum compounds in pulp suspensions were studied using fibrous cellulose (FC) and fibrous carboxymethylcellulose (FCMC) powders as models of pulp fibers by X-ray fluorescence analysis and²⁷Al nuclear magnetic resonance. When deionized water was used at pH 4–5, water-soluble cationic aluminum species (Al³⁺, aluminum oligomer, and polyaluminum species) were adsorbed on the solid FCMC, forming carboxylic acid aluminum salts by cation exchange. The formation of these nondissociated pulp-COOAl type structures in paper sheets may contribute to some decreases in hydrophilic property. On the other hand, the water-soluble cationic aluminum species had nearly no interactions with hydroxyl groups of solid cellulose in the suspensions at pH 4–5. When tap water was used at pH 5–7, some aluminum components were retained on not only FCMC but also the FC sample. Probably, water-insoluble Al(OH)₃ flocs are formed in the suspensions at pH 5–7 and retained on the FC sample by simple filtration effect. Therefore, two mechanisms of the aluminum retention (i.e., electrostatic interactions and a simple filtration effect) may exist between pulp fibers and aluminum components in the practical papermaking process.This research was presented in part at the 5th annual meeting of the Japan Cellulose Society, Kyoto, July 1998     

Antiperoxidation activity of triterpenoids from rhizome of Anemone raddeana

Four triterpenoid compounds hederacolchiside E (1), hederasaponin B (2), raddeanoside 20 (3) and raddeanoside 21 (4) were isolated from ethanol extracts of rhizome of Anemone raddeana Regel. The effects of these triterpenoids on superoxide generation, tyrosyl phosphorylation of proteins and translocation of cytosolic compounds, such as p47^phox, p67^phox and Rac to the cell membrane in human neutrophils was investigated. The superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was slightly suppressed by hederasaponin B, raddeanoside 20 and raddeanoside 21 in a concentration dependent manner. The superoxide generation induced by arachidonic acid (AA) was suppressed by hederasaponin B and raddeanoside 21 significantly. fMLP- and AA-induced tyrosyl phosphorylation and translocation of the cytosolic proteins: p47^phox, p67^phox, and Rac to the cell membrane were suppressed in parallel with the suppression of stimulus-induced superoxide generation.     

Characterization and acetylation behavior of bamboo pulp

In the present study, the chemical–physical properties of bamboo pulp prepared with a sequential totally chlorine-free procedure were analyzed and compared with that of commercial wood pulp by SEM, FTIR, TGA, and X-ray. α-Cellulose content was determined to be 95%, a little less than that of commercial wood pulp. But the crystallinity of bamboo pulp is lower than wood pulp. Acetylation activity of bamboo pulp was determined to be higher than that of wood pulp, which was carried out in heterogeneous media with sulfuric acid as catalyst. The cellulose acetate prepared with bamboo pulp can be quickly dissolved in acetone without distinct difference with that of cellulose acetate prepared with wood pulp. The results indicate the potential utility of bamboo as an alternative to wood pulp for cellulose derivate fiber material.     

Identification of two thaumatin-like proteins (TLPs) in the pollination drop of hybrid yew that may play a role in pathogen defence during pollen collection

We describe the proteomic identification of two pathogenesis-related group 5 (PR-5) proteins, an acidic thaumatin-like protein (TLP) and a basic TLP isolated from the pollination drop of hybrid yew (Taxus x media Rehder). The basic TLP (TxmTLPb) was the most abundant protein in the yew pollination drop based on protein spot size after two-dimensional electrophoresis. The acidic TLP (TxmTLPa) is also a major protein component of the yew ovular secretion and appears to be encoded by a number of mRNAs transcribed from a TLP gene family that has undergone limited sequence divergence. We have sequenced five acidic TLP-encoding cDNAs (TxmTLPa-1,2,3,4 and 5) isolated from the yew ovule that vary from each other by no more than five out of 233 amino acid residues in their predicted protein sequences. All of the cDNA variants encode TLPs possessing the 16 conserved cysteine residues and five charged amino acid side chains associated with antifungal activity. Amplification of genomic DNA with TxmTLPa primers indicated that at least 11 acidic TLPs with highly similar amino acid sequences may be expressed in yew tissues. Antibodies against TLPs confirmed the identity of TxmTLPa and TxmTLPb in the yew pollination drop and detected TLPs in the ovular secretions of four other species from three other conifer families. Our results suggest that TLPs are a conserved component of conifer ovular secretions and are involved in broad spectrum pathogen defence of ovules.     

Sulfuric acid bleaching of kraft pulp II: Behavior of lignin and carbohydrate during sulfuric acid bleaching

The purpose of this study was to investigate the behavior of lignin and carbohydrates in kraft pulps during sulfuric acid bleaching. Beech kraft pulp and red pine kraft pulp were bleached with dilute sulfuric acid at pH 1.3 with addition of sodium nitrate and sodium nitrite at 100°C for 1 h. The pulps were then extracted with aqueous sodium hydroxide solution at 70°C for 1 h. Lignin and carbohydrates in the acid effluents and the alkali effluents were analyzed. The carbohydrate compositions of unbleached and bleached kraft pulps were also determined. The residual lignin in kraft pulp was degraded to a molecular size similar to that of milled wood lignin during sulfuric acid bleaching without additives, and it was further degraded to a much smaller molecular size during sulfuric acid bleaching with additives. It was found that the amount of carbohydrate dissolved in the bleach effluents were only about 1 of the dry weight of the kraft pulp under these bleaching conditions. The carbohydrates dissolved during bleaching were mostly of hemicellulose origin.Part of this report was presented at the 8th International Symposium on Wood and Pulping Chemistry, Helsinki, July 1995