Loading...
Welcome to Chemistry and Industry of Forest Products,

Table of Content

    30 June 2006, Volume 26 Issue 2 Previous Issue    Next Issue
    研究报告
    Homogenated Extraction of Total Flavonoids from Fruits of Sea Buckthorn (Hippophae rhamnoides L.)
    ZHAO Chun-jian;ZU Yuan-gang;FU Yu-jie;LI Chun-ying;WANG Yan-bing;HOU Chun-lian
    2006, 26 (2):  38-40. 
    Abstract ( 615 )   PDF (578KB) ( 756 )   Save
    To establish an efficient method of extracting total flavonoids in the fruits of sea buckthorn(Hippophae rhamnoides L.), homogenated extraction was studied in comparing with reflux extraction. The optimum technology parameters are as follows:fruits (containing 85% water) of sea buckthorn have to be homogenated for 10 min with 85% ethanol at a ratio of liquid to solid of 5:1 (mL:g). Under the optimium condition, extraction yield of total flavonoids is 0.76% by homogenated extraction, which is equivalent to that of reflux extraction. However, homogenated extraction requires less extraction time and solvent, which is an efficient and rapid method for extracting total flavonoids from the fruits of sea buckthorn.
    Related Articles | Metrics
    Simulation on Process of Levoglucosan Formation during Cellulose Pyrolysis
    LIAO Yan-fen;WANG Shu-rong;MA Xiao-qian
    2006, 26 (2):  1-6. 
    Abstract ( 611 )   PDF (1354KB) ( 661 )   Save
    In order to optimize the yield of levoglucosan (LG) during cellulose pyrolysis, a model based on modified Brodio-Shafizadeh (B-S) mechanism model was brought out to simulate the process of decomposition and formation of active cellulose, LG and hydroxyl-acetaldehyde (HAA). Simulation results show that cellulosic material is constrained in a middle temperature condition during a rather long period of time, since heat transferred from the surrounding can not meet the endothermic need of primary cracking reaction, which virtually forms the essential condition for biomass pyrolysis to yield bio-oil. Being the most important product of cellulose pyrolysis, LG does not undergo any intensive secondary cracking, while almost all HAA is originated from the decomposition of AC. In addition, concentration differences among LG and other competitive compounds in fabric structure are determined by the competitive abilities of the corresponding reactions. This is validated by the increased accumulation tendency of HAA concentration during the late period of pyrolysis process,indicating its superiority to LG formation in consumption of AC. Secondary reactions of volatiles occur largely in gaseous phase rather than in solid phase. Both long residence time of volatiles and high temperature will induce high decomposition of LG. Therefore, to optimize the yield of LG, middle radiant-source temperature and short gas residence time are necessary. In order to optimize the yield of bio-oil, gas residence time can be slightly longer.
    Related Articles | Metrics
    Preparation and Properties of Dimeric Fatty Acid/Polyethylene Glycol Polyester Terminated with Rosin Acid
    FENG Guang-zhu;CUI Ying-de;LU Kui;QU Hai;LI He-ping
    2006, 26 (2):  7-12. 
    Abstract ( 752 )   PDF (335KB) ( 576 )   Save
    A new kind of non-ionic polymeric surfactant, the dimeric fatty acid (DFA)/polyethylene glycol (PEG) polyester terminated with rosin acid, was prepared with rosin acid and a polyester which was synthesized from DFA and PEG 400, and its surface activities were studied. The optimum reaction conditions of esterification were as follows:molar ratio of DFA/PEG 400 1:1.20, stannous chloride as the preferable catalyst at amount 0.30% of DFA, reaction temperature 200℃, reaction time 6 h, the conversion can reach 98.11%. Number-average molecular weight (Mn) of the product is 6 135. Weight-average molecular weight (Mw) of the product is 7 438. The coefficient of distribution of molecular weight (Mw/Mn) is 1.212, which indicates a narrow distribution of molecular weight. Orthogonal experiment results of rosin acid terminated reaction of dimeric fatty acid polyethylene glycol polyester showed that optimum reaction conditions were as follows:molar ratio of materials n(DFA/PEG polyester):n(rosin acid) 1:1.30, dosage of catalyst SnCl2 0.20% of polyester, reaction temperature 215℃. After 2.8 h, termination ratio of the end hydroxyl groups of polyester reached 62.75%. Rosin acid terminated DFA/PEG polyester surfactant has excellent emulsification properties, emulsification stability, power to disperse calcium soap as well as performances of defoaming and inhibiting foaming.
    Related Articles | Metrics
    A Novel Kaurane Diterpenoid from the Bark of Annona glabra Linn.
    KUAI Yu-hua;BI Zhi-ming;LI Ping;ZHANG Yong-hong
    2006, 26 (2):  13-15. 
    Abstract ( 663 )   PDF (433KB) ( 824 )   Save
    A new kaurane diterpenoid was isolated from the bark of Annona glabra Linn.Fifteen kg of bark of the plant was extracted with 95% EtOH for 3 times,each time for 2 h.The extract,which was suspended in water,was partitioned successively with petroleum ether,ethyl acetate and n-BuOH.Then the ethyl acetate fraction was subjected to silica gel column chromatography and recrystallization to afford compound 1. On the basis of chemical and spectral analysis,the structure was confirmed to be a kaurane diterpenoid,which is a novel compound,named 16α-hydroxy-17-acetoxy-ent-kauran-19-oic acid.
    Related Articles | Metrics
    Combinated Bamboo Charcoal-TiO2 -light for Degradation of Phenol
    CHEN Qing-song;YE Gui-zu;LAI Shou-lian;LI Xiao-yan
    2006, 26 (2):  16-18. 
    Abstract ( 612 )   PDF (745KB) ( 634 )   Save
    Bamboo charcoal, TiO2 and light were combinated as a synergistic system of adsorption-catalysis-photooxidation, and the characteristic of phenol degradation by this system was investigated.The effects of amount and granularity of bamboo charcoal, pH value and initial concentration of phenol on removal of phenol were discussed. The results show that the effect of photooxidation is the optimum when the amount of bamboo charcoal is 1 g/L. The smaller granularity of bamboo charcoal is, the worse is degradation of phenol. Granularities of 0.520-0.246 mm are appropriate.Acidity is propitious to degrade phenol, and when pH value is 3 the degradation effect is the best.Increase of initial concentration of phenol results in the decrease of degradation, but increase of average reaction speed.
    Related Articles | Metrics
    Celluloses of Salix psammophila and Caragana korshinskii Kom. Obtained by Alkaline Hydrogen Peroxide Process
    XU Feng;ZHONG Xin-chun;SUN Run-cang
    2006, 26 (2):  19-22. 
    Abstract ( 657 )   PDF (713KB) ( 651 )   Save
    The chemical compositions of the branches of Salix psammophila and Caragana korshinskii Kom. were assessed. Degradation of mixture of these two-shrubs was carried out by non-sulfur alkaline hydrogen peroxide (HPA) process under optimized conditions (NaOH 18%, reaction temperature 165℃, charge of hydrogen peroxide 3%, time 90 min, liquid-solid ratio 4:1(mL:g)) selected according to the previous orthogonal experiment. Results indicated that lignin and hemicelluloses were significantly degraded by alkaline hydrogen peroxide with only small amount of associated lignin (4.39% phenolic composition) on cellulose. Cellulose had relatively high purity (glucose content 84.68%). Characterizations of cellulose preparation were studied by using FT-IR, GC, HPLC and 13CNMR techniques.
    Related Articles | Metrics
    Study on Preparation of Modified Lignosulfonate/Acrylate Copolymerization Emulsion
    CHU Fu-qiang;HONG Jian-guo
    2006, 26 (2):  23-26. 
    Abstract ( 639 )   PDF (723KB) ( 634 )   Save
    Lignosulfonate (LS) is the byproduct of sulfite pulping process. In this paper vinyl group was introduced into the mole-cule of LS by reacting it respectively with maleic anhydride and acryloyl chloride. Then grafted copolymer of modified lignosul-fonate/acrylate was prepared through emulsion polymerization. It was found that as the dosage ratio of lignin to monomers was 1:5,conversion rate of non-modified LS was only 25.1%, grafting efficiency was 26.3%, grafting rate was 129.5%. For LS modified by maleic anhydride and acryloyl chloride respectively,conversion rates were 81.2% and 83%, grafting efficiencies reached 71.8% and 72.6%,grafting rates reached 378.3% and 341.4% respectively.Furthermore,the structure of modified LS and the morphology of copolymerization emulsion particles were studied by IR and TEM respectively.
    Related Articles | Metrics
    Study on Photochromic and Solvatochromic Properties of Dehydroabietylamine Salicylidene Schiff Base
    RAO Xiao-ping;SONG Zhan-qian;GAO Hong
    2006, 26 (2):  27-29. 
    Abstract ( 584 )   PDF (508KB) ( 852 )   Save
    Dehydroabietylamine salicylidene Schiff base (a) and dehydroabietylamine 5-nitrylsalicylidene Schiff base (b) were prepared in ethanol solvent.Their structures were characterized by IR spectroscopy.Their photochromic and solvatochromic properties in organic solvents were studied by UV-Vis spectroscopy. It has been found that:both a and b exhibited photochromism in chloroform solution.Base b exhibited solvatochromism in DMF solution. The mechanisms of photochromism and solvachromism of these two compounds were discussed.
    Related Articles | Metrics
    Study on the Synthesis of Palmitic Acid Monoethanolamide Polyglycoside
    HU Li-hong;ZHOU Yong-hong;SONG Zhan-qian
    2006, 26 (2):  30-32. 
    Abstract ( 863 )   PDF (619KB) ( 640 )   Save
    Palmitic acid monoethanolamide(PMEA) was synthesized by the reaction of palmitic acid with monoethanolamine. The nonionic surfactant palmitic acid monoethanolamide polyglycoside(PMEAPG),which has not been reported in the literature, was obtained by transglycosidation of PMEA with n-butyl glycoside. The suitable synthesis conditions of PMEA were:molar ratios of n-butyl to glucose and catalyst to glucose 6:1 and 0.03:1 respectively, reaction temperature 120℃, reaction time 3 h. Suitable synthesis conditions of PMEAPG were:molar ratio of PMEA to n-butyl glycoside 1:1,reaction temperature 145℃, reaction time 1 h.
    Related Articles | Metrics
    Synthesis of Amphoteric Superabsorbent Polymer Modified by Wheat Straw Cellulose
    WANG Dan;SONG Zhan-qian;SHANG Shi-bin
    2006, 26 (2):  33-37. 
    Abstract ( 629 )   PDF (391KB) ( 798 )   Save
    Superabsorbent polymers (SAPs) were prepared from wheat straw cellulose (WSC), acrylic acid (AA), acrylamide (AM) and [2-(methylacryloyloxy)ethyl] trimethylammonium chloride (MAETAC) through graft copolymerization. Factors affecting water-absorbent capacity of SAPs, such as monomers ratio, WSC dosage, contents of initiator and crosslinking agent, and neutralization degree of AA were investigated and discussed in detail. Amphoteric SAPs, with absorbent capacity of 853 times their own weight in distilled water and 118 times in 0.9% saline solution under optimized synthesis condition, were obtained.
    Related Articles | Metrics
    Studies on Cellulase Production by Immobilized Cells and Characteristics of Cellulase
    SUN Dong-mei;YANG Qian;SONG Jin-zhu;CHEN Zhong-xiang
    2006, 26 (2):  79-82. 
    Abstract ( 578 )   PDF (770KB) ( 657 )   Save
    Immobilized cells were prepared through embedment of Trichoderma aureoviride with calcium alginate. The suitable culture conditions were sodium alginate 50 g/L, initial pH value of the substrate 4.0-4.5 and using filter paper pulp as carbon source of the substrate. The enzymatic activity of the immobilized cells was improved when concentration of calcium dichloride was 20 g/L, initial pH value of the substrate was 4.5, concentration of sodium alginate was 50 g/L using filter paper pulp as carbon source of the substrate. Addition of the surfactant Twin-80 could further increase enzymatic activity. Three endoglucanases and two β-glucosidases from the fungi were separated and purified to electrophoretic homogeneity through processes of (NH4)2SO4 fractional precipitation, Sephadex G-100 gel chromatography and DEAE Sephadex A-50 ion exchange chromatography. They were designated as EGⅠ, EGⅡ, EGⅢ, BGⅠand BGⅡ, with relative molecular weights (M[HT6SS]r[HT5"SS])of 62 300, 71 900, 52 600, 85 300 and 78 300 by SDS-PAGE, and isoelectric points of 5.4, 4.8, 5.0, 5.6 and 5.8, respectively.
    Related Articles | Metrics
    Study on Preparation of Activated Carbon from Rubber-seed Shell with Steam Method
    SUN Kang;JIANG Jian-chun;ZHANG Tian-jian;DENG Xian-lun;DAI Wei-di
    2006, 26 (2):  41-43. 
    Abstract ( 713 )   PDF (501KB) ( 850 )   Save
    Using steam as activating agent, high-quality activated carbon from rubber-seed charcoal was prepared. Results of orthogonal test indicated the influences of activating temperature, activating time and flow rate of steam.The optimum activation conditions for rubber-seed shell activated carbon were as follows:activating temperature 880℃, activating time 40 min, steam flow rate 8 kg/h. Under these conditions, high-class rubber-seed shell activated carbon could be obtained, with decolorization of 240 mg/g, toward 0.15% methylene blue, iodine adsorption of 1 113 mg/g, strength of 94.2%, and yield of 40.5%.
    Related Articles | Metrics
    Study on Structural Change of Tobacco Stems during Carbonization
    ZHANG Li-bo;TU Jian-hua;PENG Jin-hui;ZHANG Shi-min;PU Jing-zhong;MA Xiang-yuan
    2006, 26 (2):  44-48. 
    Abstract ( 611 )   PDF (1081KB) ( 1015 )   Save
    Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques have been applied to investigate thermal degradation characteristics of tobacco stems (TS) and the structure of its charcoal at different carbonization temperatures, respectively. The effect of carbonization temperature on the structure of the tobacco stems-based charcoal (TSC) and carbonization mechanism of TS were discussed. Based on the results of TGA and XRD, a simple model of TS carbonization was derived. Experimental results show that weight loss during heating of dried TS in N2 atmosphere starts below 433 K and is almost terminated at 943 K, and the maximum decomposition rate in the temperature range 470-660 K could be determined by differential thermogravimetric (DTG) curve, and almost 72.85% of the total weight loss occurs in 298-1 273 K. The XRD patterns of TSCs showed three broad peaks (002), (100) and (110),which are typical of turbostratic layering and non-graphitic carbon. With increasing of carbonization temperature, the interlayer spacing of aromatic layers (d002) is decreasing, and the crystallite sizes Lc and La are changing in the ranges of 0.66-1.24 nm and 2.64-4.26 nm, respectively, which implied that there are about 2-4 graphene layers along c-axis and 10-18 aromatic rings along a-axis in crystallite of TSCs.
    Related Articles | Metrics
    Preparation of Activated Carbon with High Specific Surface Area from Coconut Shell
    SU Wei;ZHOU Li;ZHOU Ya-ping
    2006, 26 (2):  49-52. 
    Abstract ( 786 )   PDF (784KB) ( 936 )   Save
    A novel process was adopted to gain activated carbon with high specific surface area from coconut shell charcoal. The charcoal was crushed to pieces of 0.28-0.90 mm and activated by the mixture of steam and carbon dioxide for 16-17 h to obtain activated carbon with surface area greater than 2 700 m2/g.The adsorption isotherms of CO2 and CH4 at 25℃ were measured and the highest adsorption amounts reached 20.4 and 9.6 mmol/g respectively.Most pores of the activated carbon had sizes smaller than 2 nm, which were calculated by a simple method based on simplified local density theory.
    Related Articles | Metrics
    A Study on Separation and Identification of Flavonoids in Plum by Microemulsion Thin-layer Chromatography
    HAN Ming;ZENG Qing-xiao;XIAO Geng-sheng;CHEN Wei-dong;XU Yu-juan
    2006, 26 (2):  53-56,6. 
    Abstract ( 552 )   PDF (495KB) ( 798 )   Save
    A new method on separation and identification of flavonoids in plum was studied. Influence of microemulsion type on resolving power toward flavonoids was investigated with sodium dodecyl sulfate/n-C4H9OH/n-C7H16/H2O microemulsion as eluant on polyamide film. The flavonoids were separated entirely. Six flavonoid spots were obtained from fruit peel and three from pulp, but they were not identical. Compared with the general mobile phase composed of C4H9OH/CH3COOH/H2O(4:1:5), the sensitivity of detection was improved markedly and the results were satisfactory. This new chromatographic method is simple, accurate for separation and identification of flavonoids in plum.
    Related Articles | Metrics
    Study on Preparation of Rigid Polyurethane Foam from Bagasse Polyol
    PANG Hao;;LIU Yu-sheng;;LIAO Bing;ZHAO Shu-lu;HU Mei-long
    2006, 26 (2):  57-60. 
    Abstract ( 728 )   PDF (699KB) ( 815 )   Save
    Bagasse was liquefied into polyols with sulfuric acid as catalyst, and the product was used to prepare rigid polyurethane foams. The effects of catalyst, surfactant, foaming agent and isocyanate upon density and mechanical properties of foams were studied. Results showed that at dosage of catalyst B 2.53%, density is the smallest, while its influence toward compression modulus is not significant. With the increased dosage of catalyst D, both density and strength decrease. At the dosage of AK-8805 2.06%,density is the smallest and compression modulus is high. The content of NCO influences the properties of the foams, when content of PM-200 is between 200%-240% its compressive properties is the optimum.
    Related Articles | Metrics
    Supercritical Carbon Dioxide Extraction of Effective Ingredient in Chinaberry Bark
    DU Ai-ling;SUN Gong-ping;WANG Wei-qiang;MOU Da-jian;LIU Bao;
    2006, 26 (2):  61-64. 
    Abstract ( 646 )   PDF (833KB) ( 636 )   Save
    Supercritical CO2 was used to extract the effective ingredient in Chinaberry bark. Lieberman reaction, Salkwoski reaction and dimethylaminobenzaldehyde reaction were used to identify toosendanin.Uniformity design was used for the experiment scheme. Extraction rate (Y1) was measured by means of material weight loss. Absorbency (Y2) at 510 nm was measured to indicate the relative concentration of toosendanin in the extraction. Correlation equations between experimental conditions and Y1 and Y2 have been described respectively.Results showed that optimum extraction conditions of toosendanin are:pressure 28 MPa, temperature 35℃ for Y2, time 5 h and without addition of high-polar modifier.
    Related Articles | Metrics
    Comparison between Extended Delignification Cooking and Conventional Kraft Cooking of Bamboo
    CAO Shi-lin;ZHAN Huai-yu;CHEN Li-hui;HUANG You-he
    2006, 26 (2):  65-68. 
    Abstract ( 730 )   PDF (779KB) ( 609 )   Save
    In an attempt to improve bamboo-pulp properties and reduce environmental impact, laboratory simulated extended modified continuous cooking (EMCC) and conventional kraft cooking (CKC) of bamboo of minor diameters growing in Fujian were carried out in this study. The results indicate that EMCC process has a higher delignification selectivity than CKC process. Compared with conventional kraft (CK) pulp, EMCC pulp has higher screened yield, lower screening rejects, higher viscosity and better strength properties at similar Kappar number. EMCC pulp has higher tensile index, tear index and burst index than those CK at the same beating degree.
    Related Articles | Metrics
    Study on Chemical Composition and Chemi-mechanical Pulping Properties of Reed
    TANG Yan-jun;LIU Bing-yue;LI You-ming;YANG Ru-nan;XING Xiao-gong
    2006, 26 (2):  69-73. 
    Abstract ( 798 )   PDF (784KB) ( 724 )   Save
    Properties of alkaline peroxide mechanical pulp (APMP) and sulfonated chemi-mechanical pulp (SCMP) from reed were investigated, and the main chemical constituents of reed were determined. The results showed that reed used in this study has the characteristics of high cellulose content, and low contents of 1%NaOH extractives and pentosan. Optimum pretreatment conditions of APMP and SCMP of reed were selected through orthogonal or conditional experiments. APMP experimental results showed that properties of reed APMP such as brightness 57.8%(ISO), breaking length 2.82 km and tear index 3.7 mN·m2/g can be obtained after two-stage alkaline peroxide pretreatment. SCMP experimental results showed that brightness, breaking length and tear index of unbleached reed SCMP are 40.6%(ISO), 3.48 km and 4.2 mN·m2/g, respectively. High brightness of 51.3%(ISO)could be obtained when the pulp was further bleached with 2% H2O2 under the optimum condition of single stage peroxide bleaching.
    Related Articles | Metrics
    Study on Optimization of Culture Conditions for Improved Production of Lentinula edodes Laccase
    ZHANG Yu;HONG Feng
    2006, 26 (2):  74-78. 
    Abstract ( 613 )   PDF (1037KB) ( 841 )   Save
    Optimization of culture conditions for laccase production by xianggu mushroom (Lentinula edodes) was carried out and part characteristics of the crude laccase was investigated. Static cultivation was better than shaking cultivation for preparation of laccase from the edible mushroom. When culture pH value was ≥5.6, L. edodes was basically unable to grow. The best activity of laccase was found when pH value was around 3.5 and culture temperature was 25℃, though 20℃ was benefitial to the growth of mushroom. The concentration of Cu2+ from 0.2 to 1.0 mmol/L improved laccase production by L. edodes, while the optimal concentration of Cu2+ was 0.4 mmol/L. However, when concentration of Cu2+ exceeded 5 mmol/L, the growth of L. edodes was inhibited. Except 2,5-dimethoxyaniline, other four inducers, namely:ferulic acid, 2-methoxyphenol, gallic acid (3,4,5-trihydroxybenzoic acid) and veratryl alcohol (3,4-dimethoxybenzylalkohol) did not increase laccase activity significantly, but inhibited the mushroom's growth instead. Addition of Tween-80 affected the yield of laccase negatively. 2% of the activity of L.edodes laccase was retained after one hour incubation at 60℃. Using 2,2'-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as substrate, optimal reaction temperature of the laccase was 65℃ and optimum pH value was 2.2.
    Related Articles | Metrics
    Study on Production of Cellulase by Bacillus sp. X18 and X10-1-2
    YAN Hong;YANG Qian;WANG Xi-guo
    2006, 26 (2):  83-86. 
    Abstract ( 557 )   PDF (695KB) ( 802 )   Save
    Optimal culture conditions for production of cellulases using two bacterial strains (Bacillus sp. X18 and X10-1-2) were investigated. The highest level of cellulase activity was induced in the medium containing wheat bran, and their optimal mass concentration for Bacillus sp.X18 and X10-1-2 were 2.5% and 3%, respectively. Bean cake was the best nitrogen source, and their optimal mass concentration for Bacillus sp.X18 and X10-1-2 were 4% and 1%, respectively. Optimal culture temperature of cellulase production of Bacillus sp.X18 and X10-1-2 was 30℃. Optimal cultural pH values of cellulase production of Bacillus sp.X18 and X10-1-2 were 6-8 and 5, respectively. Optimal times of cellulase production of Bacillus sp.X18 and X10-1-2 were 20 and 60 h, respectively.
    Related Articles | Metrics
    Study on Synthesis of Hydrophobically Associated Cationic Starch
    LIU Xiang-yi;XU Xiao-jun;YANG Yu-ming
    2006, 26 (2):  87-92. 
    Abstract ( 454 )   PDF (625KB) ( 520 )   Save
    Hydrophobically associated cationic starch(HACS) was synthesized by inverse suspension polymerization, in which the continuous phase was cyclohexane, dispersant was Span 80-Tween 80 and initiator was redox initiator. Effects of dispersant, reaction temperature and time on soluble properties and the grafting properties were discussed. The grafted product was characterized with IR and X-ray diffraction. The experiment results showed that copolymerization can be proceeded rapidly at low temperature, and the optimum reaction condition was as follows:ratio of m(St):m(AM):m(DMDACC):m(OA) 4:7.4:1.5:0.6, content of initiator 3.1 mmol/L, grafting temperature 30℃, reaction time 3 h. The monomer conversions is 92.6%, grafting rate is 53.8% and viscosity-average relative molecular weight (MV) is 3.26×106.
    Related Articles | Metrics
    Extraction and Determination of Total Flavonoid and Juglone in Juglans mandshurica Maxim.
    SUN Mo-long;SONG Zhan-qian;FANG Gui-zhen
    2006, 26 (2):  93-95. 
    Abstract ( 911 )   PDF (599KB) ( 950 )   Save
    The extractions of total flavonoid and juglone ffrom leaves, bark and green peel of Juglans mandshurica Maxim. trees were carried out by three extracting methods respectively, including common method, reflux method and ultrasonic method.UV spectroscopy was used for determining the amount of total flavonoid, and HPLC was used for determining the amount of juglone. Results showed that amounts of total flavonoid and juglone are in the order of:ultrasonic method>common method>reflux method. Furthermore amounts of total flavonoid extracted from three materials by all three method showed the order of leaves>bark>green peel. Amounts of juglone extracted from three materials by all three method showed the order of:green peel>leaves>bark. The amounts of total flavonoid and juglone extracted by ultrasonic method are:5.00% and 0.00209% for leaves, 4.17% and 0.00131% for bark, 3.05% and 0.002 29% for green peel, respectively.
    Related Articles | Metrics
    Comparison of Cooking Kinetics between Wheat Straw and Cotton Stalk
    WANG Jian;ZHAN Huai-yu;CHEN Jia-chuan
    2006, 26 (2):  96-98. 
    Abstract ( 625 )   PDF (622KB) ( 565 )   Save
    Comparison of cooking kinetics between cotton stalk and wheat straw was studied in this paper. A novel experimental and calculating method for the study of cooking kinetics was established. By application of identical liquor ratio as used in actual cooking conditions, activation energies of soda-AQ cooking of cotton and wheat pulps were obtained from determinations of effective alkali concentration and residual lignin content, as well as from calculation of reaction rate constant. Activation energies of soda-AQ cooking of cotton stalk and wheat straw were basically unchanged during the whole cooking period. Activation energy of soda-AQ cooking of wheat straw was 51.0 kJ/mol which was lower than that of soda-AQ cooking of cotton stalk at 138.1 kJ/mol, which indicated that delignification of wheat straw was easier than that of cotton stalk during soda-AQ cooking.
    Related Articles | Metrics
    综述评论
    Hydrolysis of Woody Biomass
    LUO Peng;LIU Zhong
    2006, 26 (2):  99-104. 
    Abstract ( 665 )   PDF (957KB) ( 743 )   Save
    Hydrolysis is an important step for bioconversion of woody biomass to ethanol. Hydrolysis technology includes dilute acid hydrolysis, concentrated acid hydrolysis and enzymatic hydrolysis. Featured as selective attack, less degradation product, high recovery of glucose, low energy consumption, no demand on anti-corrosive reactor, enzymatic hydrolysis has been regarded as the potential breakthrough to lower the cost of ethanol production. Currently the cost of bioconversion of biomass to ethanol is higher than those of starch and sugar due to high cost of raw material pretreatment, expensive cellulase production, low cellulase activity, low efficiency of enzymatic hydrolysis, high cellulase loading and insufficient utilization of hemicellulose. Therefore, effective pretreatment technology should be developed to improve enzymatic digestibility of cellulose, selection of high-efficient cellulase and optimization of enzymatic hydrolysis should be conducted to raise the rate of enzymatic hydrolysis. Conversion of 5-carbon sugars into ethanol by means of genetically engineered microorganisms should be conducted to raise ethanol production.
    Related Articles | Metrics
    Progress of Researches on Applications of Manganese Peroxidase
    LIU Meng-ru;FU Shi-yu;ZHAN Huai-yu;LIN Lu
    2006, 26 (2):  112-116. 
    Abstract ( 682 )   PDF (891KB) ( 642 )   Save
    Manganese peroxidase(MnP)is an important enzyme due to its potential applications. In this paper,the MnP-producing microorganism and the applications of MnP in biobleaching of pulp, degradation of organic pollutants, decoloration of dyes, degradation of lignite and catalytic polymerization are reviewed
    Related Articles | Metrics
    Microbial Degradation of Hydrolysable Tannins
    LI Ming-shu;YAO Kai;JIA Dong-ying;HE Qiang
    2006, 26 (2):  105-111. 
    Abstract ( 801 )   PDF (406KB) ( 677 )   Save
    Tannins are water-soluble polyphenolic secondary metabolites of higher plants with the molar mass from 300 to 3000. Hydrolysable and condensed tannins are the two major classes of tannins. There are two groups of hydrolysable tannins:gallotannins and ellagitannins on the basis of structural characteristics. In nature, some microbes are resistant to tannins, even capable of degrading tannins into low-molar-mass tannins and lots of derivatives which have marked biological and pharmacological activities. Gallotannins can be degraded more easily than ellagitannins which have complicated structures with the further coupling C—C bond. However, some bacteria and fungi from the ellagitannin-rich soil, leaves and tannery liquors can hydrolyze ellagitannins. Because of the complicated structures of the further coupling C—C bonds, both complex tannins and condensed tannins are harder to be degraded than gallotannins and ellagitannins in both aerobic and anaerobic environments. This review could provide much references for the further researches on biodegradation of tannins.
    Related Articles | Metrics
    Spray Drying of Substances Containing Sugars
    HAN Lei;TANG Jin-xin;WU Ya-fei;WANG Zong-lian
    2006, 26 (2):  117-121. 
    Abstract ( 835 )   PDF (894KB) ( 1177 )   Save
    Based on the understanding of the relation between glass transition temperature and stickiness,the reason of sticking of substances containing different kinds of sugars on the drier chamber wall during their spray drying was analysed and six methods were suggested to solve this problem,including modification of the substances and improvement of design of the drying process。
    Related Articles | Metrics
    Progress in Research on Urea-formaldehyde Resin of Wood Industry
    JIN Li-wei;CHEN Ri-qing;WANG Chun-peng;LIU Yi;ZHAO Lin-wu
    2006, 26 (2):  122-126. 
    Abstract ( 601 )   PDF (895KB) ( 776 )   Save
    The theoretical researches on urea-formaldehyde resin and its practice in wood industry were reviewed in detail. With application of nuclear magnetic resonance in structure researching of urea-formaldehyde resin, minor structural differences can be clearly distinguished. Effects of reaction condition in urea-formaldehyde resin production, especially during the acid stage, on the formaldehyde emission were discussed. Modes of modification of urea-formaldehyde resin were listed. Their properties after modification were also studied.
    Related Articles | Metrics
    研究简报
    Effects of Xylanase Treatment on Chemical Composition of Wheat Straw and Fiber Length of Its Pulp
    LI Xue-zhi;ZHAO Jian;QU Yin-bo
    2006, 26 (2):  127-130. 
    Abstract ( 690 )   PDF (725KB) ( 573 )   Save
    Wheat straw was pretreated by crude xylanase prior to chemical pulping, and effects of enzyme treatment on chemical composition of wheat straw and fiber length of its chemical pulp were investigated. The results show that contents of hot-water extractive and 1% NaOH extractive were increased, and alcohol-benzene extractive content was lowered by xylanase treatment. Xylanase treatment had a slight influence on Klasson lignin content, but lowered pentosan content.The extraction with low consistency sodium hydroxide solution after enzymatic treatment led to the decreases of Klasson lignin and pentosan contents effectively. Compared to the control, chemical pulp from xylanase-pretreated wheat straw has a longer length of fiber.
    Related Articles | Metrics
    Study on Supercritical Carbon Dioxide Extraction of Ursolic Acid in Rabdosia rubescens (Hemsl.)Hara
    YUAN Ke;SUN Wei;ZHANG Xiao-ming
    2006, 26 (2):  131-134. 
    Abstract ( 592 )   PDF (759KB) ( 682 )   Save
    Technique of supercritical carbon dioxide extraction(SCDE) of ursolic acid in Rabdosia rubescens (Hemsl.)Hara was studied.The optimal extraction conditions were achieved for 1 kg material as follows:extracting pressure 20 MPa, size of granules 40 mesh, extracting temperature 40℃, CO2 flow rate 15 L/h, extracting time 3 h, modifier 95% alcohol,at dosage of 30% of raw material.The yield of product is 4.17%. The content of ursolic acid in the product is 6.24%determined by HPLC. The result shows that the method has the advantages of simple operation, less solvent consumption, short extraction time, high extraction yield and no interference of impurity during determination.
    Related Articles | Metrics
    Study of Reaction Conditions on Synthesis of Nopinic Acid from β-Pinene
    JIN Jian-zhong;SHEN Min-min;HA Cheng-yong
    2006, 26 (2):  135-136. 
    Abstract ( 572 )   PDF (401KB) ( 787 )   Save
    Nopinic acid (2-hydroxy-6,6-dimethyl bicyclo[3,1,1] heptane-2-carboxylic acid) has been synthesized through oxidation of β-pinene by potassium permanganate. The influences of the factors in the reaction were investigated. The optimum conditions for preparing nopinic acid are:n(β-pinene):n(KMnO4):n(NaOH) 1:2.5:1, water as solvent, reaction temperature 25-30℃ and reaction time 4-5 h. The yield is 35%.
    Related Articles | Metrics