Effect of High Temperature on Sucrose Content and Sucrose Cleaving Enzyme Activity in Rice Grain

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厌氧折流板反应器_ABR_的启动及酸化的恢复

厌氧折流板反应器 (ABR - Anaerobic Baffled Reactor) 是一种新型高效厌氧反应器 ,从结构看相当于几个升流式污泥床反应器 (USB - Upflow Sludge Bed)的串联 ,实现了产酸菌群和产甲烷菌群在不同隔室生长的条件 ,在高浓度有机废水的处理中有特殊的优势。本文介绍了厌氧折流板反应器的原理及其相关研究的进展情况。 1 厌氧折流板反应器的原理 111 良好的水力特征 ABR反应器内设置若干竖向导流板 ,将反应器分隔成串联的几个反应室 ,每个反应室都可以看作一个相对独立的升流式污泥床系统 ( upflow sludge bed,简称 USB ) ,废水进入反应器后沿导流板上下折流前进 ,依次通过每个反应室的污泥床 ,废水中的有机基质通过各反应室并与其中的微生物充分接触而得到去除。借助于水流的上升和沼气搅动的作用 , 反应室中的污泥上下运动 ,水流在不同隔室中流态呈现完全混合态。但是由于导流板的阻挡和污泥自身的沉降性能 ,污泥在水平方向的流速极其缓慢 ,从而大量的厌氧污泥被截留在反应室中 ,反应器在整个流程方向则表现为推流式流态 [1, 2 ] 。 112 阶段化多相厌氧反应器在展望先进的厌氧处理技术时 , Lettinga[3 ] 提出了阶段化多相厌氧 ( staged M ulti一 Phase Anaerobic reactor system ,简称 SMPA )反应器 ,它不仅能在更高的负荷率下提供更好的处理效率 ,而且适应于极端的环境条件和抑制性化合物。
tech1 1997, 69 ( 2) : 276 - 284
(责编 :张杨林 )
(上接 66 页 ) PolII p romoter sequences, B ioinformatics, 1999, 15:

高温高Cl-含量环境中H_(2)SCO_(2)分压对超级双相不锈钢UNS S32750点蚀行为的影响

第42卷第2期腐蚀与防护 Vol. 42 No. 2 2021 年2 月CORROSION &. PROTECTION February 2021I)()l：10. 11973 fsyfh-202102006高温高C l'■含量环境中h2s/c o2分压对超级双相不锈钢UNS S32750点蚀行为的影响樊学华\于勇，陈丽娟、迟遥，刘艺盈、刘畅(1.中国石油工程建设有限公司北京设计分公W •北京10008「)：2.中国石油工程建设有限公司•北京100120)摘要：在高温、高C1含量及不同H:S (；():分压条件下对超级双相钢UNSS32750进行了腐浊浸泡试验，并采用失重法、激光共聚焦显微镜、X-射线光电子能谱（XPS)分析了超级双相不锈钢UNS S32750的均匀腐蚀速率、点蚀形貌和表面钝化膜组成。

结果表明•.在试验条件下当H iS/a)；：分〖丨(不大于30 kPa 150 kP a时•超级双相不锈钢UNS S32750具有良好的耐均匀腐蚀和点蚀性能；但当H:>S/C().分丨K为100 kP?l/500 k P a时.H::S造成了钝化膜的局部破坏•引发阳极性溶解•使超级双相不锈钢UNSS32750发生点蚀；钝化膜主要由FeS2、Ni()、NiS、C'r()3及Fe(()H) 组成。

关键词：超级双相钢UMSS32750;点蚀；H S;C():中图分类号：TG174 文献标志码：A 文章编号：1005-748X(2021)02-0032-05Effects of H2S/C02Partial Pressures on Pitting Behavior of Super Duplex Stainless Steel UNS S32750 in a Environment of High Temperature and High Chloride ContentFAN Xuehua1 ,YU Yong1 ,CHEN Lijuan1 ,CHI Y a o M JU Yiying1 ,U U Chang1(1. Beijing Engineering Branch. C'hina Petroleum Engineering ^ ■C'onstruction Co. . Ltd. . Beijing 100085. China；2. China Petroleum Engineering Construction C'o. . Ltd. . Beijing 100120, China)A b stract：Corrosion immersion tests were conducted on super duplex stainless steel (SDSS) UNS S32750 in aenvironment of high temperature, high chloride concentration and different partial pressures of H-S and CO-. The general corrosion rate, pitting corrosion morphology of SDSS UNS S32750 and composition of passive film on its surface by the methods of mass loss. laser confocal microscopy and X-ray photoelectron spectroscopy ( XPS) techniques. The results show that the SDSS UNS S32750 had a good general corrosion resistance and pitting corrosion resistance when the partial pressures of HL；S and C'(): were no higher than 30 kPa and 150 kPa respectively under the test condition. When the partial pressures of H S and CO were 100 kPa and v500kPa respectively, pitting corrosion happened to the SDSS UNS S32750 due to the localized loss of the passive film and consequent anodic dissolution. The passive film was mainly composed of FcS」，Ni(). NiS，（、r. (); and Fe(OH)」.Key words：super duplex stainless steel UNS S32750；pitting corrosion；H2S；CO：随着高含H，S和高含盐油气田的开发，服役工况日益苛刻，特别是稠油的开发.脱水温度高.给油田地面设施的安全运行以及材料选择提出了更高的要求。

The effects of Tween 20 and sucrose on the stability of anti-L-selectin during lyophilization

The Effects of Tween 20and Sucrose on the Stability of Anti-L-Selectin during Lyophilization and ReconstitutionLATOYA S.JONES,1THEODORE W.RANDOLPH,2ULRICH KOHNERT,3APOLLON PAPADIMITRIOU,3G.WINTER,3MARIE-LUISE HAGMANN,3MARK C.MANNING,1JOHN F.CARPENTER 11School of Pharmacy,University of Colorado Health Sciences Center,Denver,Colorado 802622Department of Chemical Engineering,University of Colorado at Boulder,Boulder,Colorado 803093Boehringer Mannheim,Penzberg,GermanyReceived 19December 2000;revised 24May 2001;accepted 25May 2001ABSTRACT:We have chosen an anti-L-selectin antibody as a model protein to investigate the effects of sucrose and/or Tween 20on protein stability during lyophilization and reconstitution.Native anti-L-selectin secondary structure is substantially retained during lyophilization in the presence of sucrose (1or 0.125%).However,aggregation of the protein during reconstitution of lyophilized protein powders prepared without sucrose is not reduced by the presence of sucrose in the reconstitution medium.Aggregate formation upon reconstitution is completely inhibited by freeze drying the protein with sucrose and reconstituting with a 0.1%Tween 20solution.Tween 20(0.1%)also partially inhibits loss of native anti-L-selectin secondary structure during lyophilization.However,upon reconstitution the formula-tions lyophilized with Tween 20contain the highest levels of aggregates.The presence of Tween in only the reconstitution solution appears to inhibit the transition from dimers to higher order oligomers.Potential mechanism(s)for the Tween 20effects were investigated.However,no evidence of thermodynamic stabilization of anti-L-selectin conformation (e.g.,by Tween 20binding)could be detected.ß2001Wiley-Liss,Inc.and theAmerican Pharmaceutical Association J Pharm Sci 90:1466±1477,2001Keywords:lyophilization;reconstitution;antibody formulation;infrared spectro-scopy;protein aggregationINTRODUCTIONTo optimize protein stability during storage and shipping,lyophilized formulations are often employed.However,a lyophilized product has itsdrawbacks:the possibility for protein denatura-tion exists during both the freeze drying 1±6and reconstitution 7,8processes.Excipients are often critical for maintaining native protein con-formation during freezing and drying,and mini-mizing levels of protein aggregation in the reconstituted product.2±5,9±14The purpose of the present study is to investigate the effects of Tween 20and sucrose on the stability of an anti-L-selectin antibody during lyophilization and reconstitution.Lyophilization involves both freezing and dehydration steps,each capable of promoting protein denaturation.Sucrose inhibits protein un-folding during freezing and drying.1,5,6,9,12,15±18However,studies of structural preservation of1466JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER 2001Ulrich Kohnert's present address is Scil Biomedicals GmbH,Fraunhofer Str.15,D-82152,Martinsried,Germany.Apollon Papadimitriou's present address is Roche Diagnos-tics GmbH,Pharma Research,Penzberg,Germany.G.Winter's present address is Lehrstuhl fu Èr Pharmazeu-tische Technologie und Biopharmazie,Ludwig MaximiliansUniversita Èt Mu Ènchen,Germany.Correspondence to :J.F.Carpenter (Telephone:303-315-6075;Fax:303-315-6281;E-mail:john.carpenter@)Journal of Pharmaceutical Sciences,Vol.90,1466±1477(2001)ß2001Wiley-Liss,Inc.and the American Pharmaceutical Associationantibodies during lyophilization are limited.19 During freezing,sucrose inhibits protein denaturation by increasing the free energy of protein unfolding.20±22During dehydration, sucrose stabilizes a protein by replacing the hydrogen bonds between the protein and water molecules that are lost during drying.1,23The current study employs infrared spectroscopy to characterize the secondary structure of anti-L-selectin in the initial aqueous and lyophilized states.The experiments test the hypothesis that sucrose inhibits lyophilization-induced unfolding. The stabilization of proteins by surfactants is often attributed to limiting the extent of protein adsorption at various potentially denaturing interfaces(e.g.,ice/liquid,air/liquid,vial/ liquid).14,24±27In addition,nonionic surfactants can stabilize some proteins,such as human growth hormone24,29,30and tissue factor,28by binding to solvent exposed hydrophobic regions of the native state protein.Surfactants have been shown to inhibit protein denaturation during freeze thawing.3,15,18,26However,unlike excipi-ents such as sucrose,surfactants have a limited capacity to inhibit lyophilization-induced unfold-ing via the water replacement mechanism. Accordingly,Kreilgaard et al.found that Tween 20(0.002%)did not inhibit lyophilization-induced unfolding of Factor XIII.5In contrast,Chang et al. found that Tween80(0.1%)partially inhibited lyophilization-induced unfolding/aggregation of interleukin-1receptor antagonist,but this study was conducted under grossly destabilizing condi-tions that led to50%aggregation after reconstitu-tion.3There appears to be no published study that directly determines the effect of nonionic surfac-tants on the lyophilization-induced unfolding of antibodies.Thus,a second goal of the current study is to test the hypothesis that Tween20 should not inhibit the lyophilization-induced unfolding of anti-L-selectin.Lyophilized drugs must be reconstituted prior to administration.Aggregates have been pro-posed to form during reconstitution from a fraction of nonnative protein molecules that are present in the dried solid.17Minimizing protein unfolding during lyophilization by inclusion of excipients such as sucrose can reduce the level of aggregates present after reconstitution.16,31,32 Inclusion of surfactants(e.g.,Tween20)in the reconstitution solution might alter kinetics to favor refolding over aggregation.Typically,water alone is used to reconstitute the lyophilized product.Prestrelski et al.found that someexcipients(e.g.,0.1and0.5%Tween20,0.05% EDTA)in the reconstitution solutions reduced aggregation of keratinocyte growth factor and interleukin-2,whereas others(e.g.,N-octylgluco-side,Pluronic)had no signi®cant effect on keratinocyte growth factor but promoted aggrega-tion of interleukin-2.7,8They also found that additives in the reconstitution medium decreased the amount of soluble ribonuclease A aggregates.8 These studies focused only on proteins that had been stored at458C for2or more weeks, prior to reconstitution.7,8There are two published reports on the effects of surfactant solution on reconstitution of proteins immediately after lyo-philization.Chang et al.report that the presence of0.1%Tween80in the reconstitution medium decreased aggregation of interleukin1-receptor antagonist.3A reconstitution solution of0.02% Tween80was equally as effective at inhibiting aggregation of bovine IgG as the inclusion of either0.02or0.1%Tween80in the initial lyophilized formulation.14However,separate effects of the surfactant on inhibiting lyophiliza-tion-induced unfolding and fostering refolding during reconstitution were not tested.We hypothesize that,although Tween20might not completely inhibit structural perturbations of the protein during lyophilization,it will foster reduced levels of aggregation during reconstitu-tion.Furthermore,the effects of low concentra-tions of sucrose in the reconstitution solution will be evaluated.EXPERIMENTAL SECTIONMaterialsPuri®ed anti-L-selectin antibody was produced by Boehringer Mannheim(Mannheim,Germany) and was stored atÀ808C until needed.The protein is a humanized murine IgG4antibody.Upon thawing and dialysis,our SE-HPLC analy-sis(see below)revealed approximately98% monomer and2%dimer.Potassium phosphate monobasic,potassium phosphate dibasic,guani-dine hydrochloride(GdnHCl),infrared grade potassium bromide(KBr),and Tween20(Sigma Ultra)were purchased from Sigma Chemical Company.High-purity sucrose was purchased from Pfansteihl.Total protein assay(BCA)solu-tions were purchased from Pierce Chemical Company.All protein and excipient solutions were freshly prepared using distilled deionizedTWEEN20,SUCROSE,AND ANTI-L-SELECTIN1467 JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER2001water.Buffer solutions were®ltered through 0.45-micron nylon®lters.Lyophilization StudyAnti-L-selectin was concentrated to2.3mg/mL using an Amicon stir cell concentrator with a YM10®lter.The protein was then dialyzed against three changes of600mL10mM potas-sium phosphate buffer(pH7.2)for at least18h. This buffer was chosen to avoid pH decreases during freezing.However,it should be noted that Anchordoguy et al.reported that10mM potas-sium phosphate buffer adjusted to pH7.5at228C alkalinized to pH8.1upon freezing.33Follow-ing dialysis,the protein was reconcentrated to 4.8mg/mL as above.Solutions of5%(w/v)sucrose in buffer and1.0%(w/v)Tween20in buffer were prepared in buffer.Anti-L-selectin formulations to be lyophilized were®rst prepared in eppendorf tubes by combining the appropriate buffer and excipient solutions,then adding protein stock solution to obtain2mg/mL anti-L-selectin in a total volume of300m L.The samples were then transferred to1-mL lyophilization vials(West Company)and placed in a freeze dryer(FTS Systems DuraStop).Table1provides a summary of the excipients and their concentrations in the ®ve lyophilized formulations.Vials were placed on a room temperature freeze-dryer shelf.The shelf temperature was reduced at a rate of18C per minute until the temperature of representative sample reached À308C.The shelf was held at this temperature for 2h.Then the shelf temperature was reduced to À408C at18C per minute.The chamber pressure was reduced to60mTorr,and shelf temperature was maintained atÀ408C for12h.Next,the shelf temperature was increased toÀ208C at18C per minute and held for an additional6h.Finally,the shelf temperature was raised to308C at a rate of 0.58C per minute,and held at this temperature for approximately8h.Vials were stoppered while under vacuum,and analysis of the lyophilized formulations began the same day they were removed from the freeze dryer.Any vials that could not be analyzed that day were stored at À808C for no more than2days.Infrared(IR)spectroscopy was used to compare secondary structure of anti-L-selectin in lyophi-lized formulations to that of native aqueous anti-L-selectin.Spectra were obtained using a Bomem Prota infrared spectrometer.For the aqueous native protein sample,dialyzed anti-L-selectin was concentrated to approximately20mg/mL with a Centricon10concentrator.The concen-trated protein was then injected into a cell with CaFl2windows separated by a6-micron mylar spacer,and spectra were collected as described by Dong and colleagues.34For each freeze-dried formulation,the contents of a single vial contain-ing lyophilized anti-L-selectin were combined with approximately300mg KBr and pressed into a pellet as described by Kreilgaard et al.5The spectra were corrected for background(and buffer,in the case of the liquid control),converted to second derivative spectra,and smoothed using a seven-point ing Grams software, the smoothed spectra were area normalized and overlaid for comparison.35Reconstitution StudyThe excipient solutions for reconstitution were prepared in water instead of buffer to avoid increasing the®nal buffer salt concentrations of the samples.Samples were reconstituted by pipetting300m L of the reconstitution solution or water(room temperature)directly onto the cakes in the vials.Contents were gently swirled by hand until the solutions were clear.Table2shows the reconstitution schemes.Lyophilized formulations lacking sucrose(buffer alone or Tween20as the sole excipient)were reconstituted with water,1% sucrose,and0.125%sucrose solutions.Analo-gously,the lyophilized formulations with buffer alone or sucrose as the excipient were reconsti-tuted with water and a0.1%Tween20solution. The formulation lyophilized in buffer alone was the only one reconstituted with an aqueous so-lution containing both0.1%Tween20and0.125% sucrose.Following reconstitution,the samples were transferred to eppendorf tubes and centri-fuged in a benchtop microfuge at48C for10min.Table1.Final Excipient Concentrations of Anti-L-Selectin Lyophilization Formulations aFormulation 0.125%Sucrose1.0%Sucrose0.1%Tween2012345a All formulations had a®nal anti-L-selectin concentrationof2mg/mL.The buffer was10mM potassium phosphate (pH7.2).( )-Indicates the formulation contains the excipient. 1468JONES ET AL.JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER2001The tubes were then checked visually for pelleted protein.A total protein assay was performed on the supernatant(Pierce BCA assay,using anti-L-selectin that had not been lyophilized to construct the standard curve)to quantify the amount of soluble protein remaining.The concentration of the anti-L-selectin standard was determined by UV spectroscopy(e 1.45cmÀ1gÀ1L).Size-exclusion high-performance liquid chro-matography(SE-HPLC)was utilized to quantify levels of monomeric protein and soluble aggre-gates.The various aggregation states of the protein were separated using a Tosohaas TSK 3000SWLx gel®ltration column connected to a Dionex chromatography system(Sunnyvale,CA). The mobile phase was200mM potassium phos-phate(pH6.9)with150mM KCl,and the¯ow rate was0.2mL/min.The samples,chromatography system,column,and buffer were all maintained at 48C throughout the analysis.Anti-L-selectin that had not been lyophilized was used as a control. Data collected were imported into Grams software program,and curve®tting was used to deconvolve areas of overlapping peaks.The percentages of dimer and oligomer contents were calculated by dividing the areas under the curves(AUCs)of the respective curve-®tted peaks by the total AUCs of all peaks in the chromatogram of a given sample. Statistical signi®cance of differences between the amounts of aggregates of the various samples was obtained using a Student's t-test with a95% con®dence interval.Tween20±Anti-L-Selectin InteractionsThe GdnHCl-induced unfolding of0.3mg/mL anti-L-selectin in10mM potassium phosphate (pH7.2)was followed using an Aviv circular dichroism(CD)spectrometer(Model62DS).Stock solutions of7.3M GdnHCl in buffer,with and without0.1%Tween20,were prepared as described by Pace et al.36For the Tween20 experiment,0.1%Tween20was added to the buffer,protein,and GdnHCl stock solutions prior to combining the stock solutions to prepare the samples with various GdnHCl concentrations. Samples lacking anti-L-selectin were used as blanks to correct for non-anti-L-selectin contribu-tions to far UV CD signal.A1-mm pathlength sample cell was used for all CD spectroscopic measurements.Sixty-second averages of far UV CD signals at220nm of samples having0±7M GdnHCl were collected to obtain protein-unfold-ing curves.The fraction-unfolded curves were constructed using the linear extrapolation method previously described by Pace et al.36 Finally,full far UV CD scans of anti-L-selectin in0and7.0M GdnHCl solutions,with and without0.1%Tween20,were taken from260to 211nm at a step size of0.5nm with a3-s averaging time.These spectra were corrected by subtracting the wavelength scans of the four corresponding solutions without protein. Binding of Tween20to native anti-L-selectin was investigated using electron paramagnetic resonance(EPR)spectroscopy(Bruker ESP300) as described by Bam et al.30Brie¯y,16-doxyl stearic acid serves as a hydrophobic spin probe capable of partitioning into hydrophobic environ-ments.Partitioning affects the spectral signal by broadening the peaks,resulting from the decrease in rotational mobility of probe molecules in micelles.The spectrum for any given sample is a combination of signals from freely rotating and rotationally hindered probe populations(cf.ref.30).Both pure surfactant micelles and surfac-tant±protein complexes can provide hydrophobic environments that result in hindered probe rotation.In the present study,the spin probe was formulated with0to1630m M Tween20inTable2.Reconstitution Schemes for Lyophilized Anti-L-Selectin aLyophilization FormulationReconstitution SolutionsWater0.125%Sucrosein Water1.0%Sucrose inWater0.1%Tween20inWater0.125%Sucrose and0.1%Tween20inWater12345a( )-Indicates the lyophilized formulation was reconstituted with this solution.TWEEN20,SUCROSE,AND ANTI-L-SELECTIN1469JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER2001both the absence and presence of10mg/mL anti-L-selectin.The Tween20concentrations spanned below and above the critical micelle concentra-tion,CMC,(&60m M)and provided investigations of potential interactions from0:1to24:1molar ratios of Tween20:anti-L-selectin.Spectra were collected at a constant frequency of9.75GHz and centered at a magnetic®eld of3470G.Data were analyzed using DaDisp and Microsoft Excel spreadsheets as previously described.30RESULTSEffects of Excipients on Lyophilization-Induced Protein UnfoldingThe conformationally sensitive amide I region of infrared spectra34was used to compare the secondary structure of native anti-L-selectin anti-body in aqueous solution to that found in lyophilized formulations.Infrared spectroscopy was also used to monitor the secondary struc-ture of anti-L-selectin(20mg/mL)during freeze thawing.Within the resolution of this technique, anti-L-selectin's secondary structure was not perturbed during freezing or thawing(data not shown).In addition,freeze-thawing experiments of1mg/mL solutions documented that protein aggregates were not induced by this treatment. When anti-L-selectin was freeze dried without excipients there was a decrease in the peak depth at the main b-sheet band,1640cmÀ1,relative to the spectrum for native,aqueous anti-L-selectin, indicating a loss of native b-sheet(Figure1A).The broadening of the bands at1660and1675cmÀ1 was due to perturbation of native turn structures (Figure1A).Including 1.0or0.125%sucrose (Figure1A and B)prevented loss of native b-sheet structures.However,the presence of sucrose did not completely prevent perturbation of native turn structures(Figure1A and B). Tween20(0.1%)only partially inhibited loss of native b-sheet and did not prevent the perturba-tion of turn structures(Figure1C).Samples lyophilized with both0.125%sucrose and0.1% Tween had secondary structural retention that was essentially the same as that for antibody formulated with sucrose alone(Figure1D).Reconstitution StudyAfter reconstitution,all formulations contained only soluble protein.Precipitated protein was not detected by either visual inspection or by centrifugation and analysis of the supernatant for total protein content(results not shown).How-ever,soluble aggregates were identi®ed using size-exclusion high-performance liquid chromato-graphy.Chromatograms of the reconstituted protein and that of the native control material were used for determining recovery of soluble protein(Figure2).Two peaks,instead of a single peak,were®t to the monomer peak to account for its asymmetry.The relative curve-®t areas were used to calculate the fractions of each aggregate type and monomeric protein.The soluble aggregate content was measured for anti-L-selectin samples that were lyophilized in buffer alone and reconstituted in various solutions(Figure3A).It is important to note that the starting material contained2%dimer and no detectable higher order oligomers.Water and aqueous sucrose solutions were equivalent recon-stitution media for this formulation.Dimer levels remained at2%,but there was also almost1.5% oligomer.Formation of oligomers was inhibited by reconstituting with0.1%Tween20solutions,with or without sucrose.However,there was a con-comitant increase in dimers,relative to the level in the control solution.Addition of0.125%or1.0%sucrose to the reconstitution solution had no effect on the level of protein aggregation(Figure3A and C).How-ever,anti-L-selectin freeze dried with0.125or 1.0%sucrose,which inhibited lyophilization-induced unfolding,and reconstituted with water had signi®cantly lower oligomer content than protein samples lyophilized with buffer alone and reconstituted with either water or sucrose solu-tions.Reconstitution of either sucrose formula-tion with a0.1%Tween20solution resulted in control levels of dimer and no detectable oligo-mers(Figure3B).The presence of0.1%Tween20in the lyophi-lized formulation caused the highest levels of aggregates noted in this study(Figure3C).For both Tween20formulations tested,there were higher levels of dimers than noted for samples lyophilized with only buffer,independent of the reconstitution solutions tested.Oligomer levels were approximately the same as those for the sample lyophilized in buffer alone.Tween20Interactions With Anti-L-SelectinIn an attempt to gain insight into potential mechanisms of these effects of Tween20on the recovery of native protein during reconstitution,1470JONES ET AL.JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER2001we examined the interactions between Tween 20and anti-L-selectin.Based on far UV CD spectro-scopy the native conformation of this b -sheet protein was not affected by the presence of 0.1%Tween 20(Figure 4A).Moreover,the spectra for the completely denatured state in 7M guanidine HCl (Figure 4B)were also identical,in the presence and absence of 0.1%Tween 20.Thus,any Tween bound to the protein did not alter the secondary structure of the protein in either the native or denatured state.EPR spectroscopy was used to determine if Tween 20bound to anti-L-selectin.30Analysis of the EPR data indicated that Tween 20did not bind to native anti-L-selectin (Figure 5).If Tween 20bound to anti-L-selectin,we would expect a signi®cantly higher fraction of the probe mole-cules to partition into micellar environments in the presence of anti-L-selectin than in its absence (cf.ref.30),which was not the case (Figure 5).To determine if Tween 20alters the thermo-dynamic stability of anti-L-selectin,GdnHClFigure parison of the effects of excipients on the secondary structure of anti l-selectin (anti-L-selectin)in the freeze-dried solid.(A±C)solid line:Liquid control;dotted line:anti-L-selectin freeze dried in buffer alone.(A)Dashed line:anti-L-selectin freeze-dried with 1.0%sucrose in buffer.(B)Dashed line:anti-L-selectin freeze dried with 0.125%sucrose in buffer.(C)Dashed line:anti-L-selectin freeze dried with 0.1%Tween 20in buffer.(D)Solid line:liquid control;dotted line:anti-L-selectin freeze dried with 0.1%Tween 20in buffer;dashed line:anti-L-selectin freeze dried with 0.125%sucrose in buffer;dashed-dotted line:anti-L-selectin freeze dried with 0.1%Tween 20and 0.125%sucrose in buffer.TWEEN 20,SUCROSE,AND ANTI-L-SELECTIN 1471JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER 2001unfolding curves were measured in the presence and absence of 0.1%Tween 20(Figure 6A).The curves were superimposable (Figure 6A).The calculated free energy of unfolding of anti-L-selectin was approximately 3.5kcal/mol in either formulation (Figure 6B).DISCUSSIONEffects of Excipients on Lyophilized-Induced Unfolding of Anti-L-SelectinIn general,retention of native protein structure in lyophilized formulations requires protection of the protein during both freezing and drying.16,17Freezing protection depends on the initial bulk concentration of sucrose.10The stabilization of proteins by sucrose during freezing is explained by the preferential exclusion mechanism,because the stabilization actually involves the solutes in the non-ice phase.37In contrast,protein stabilization by sucrose during drying depends on the mass ratio of sugar to protein.38For a lyophilized protein solution,a much lower initial sucrose concentration is needed for protection during dehydration than during freezing.For example,Allison et al.found that maximum protection of lyophilized actin,a freeze-labile protein,was achieved with an initial sucrose:protein mass ratio of 5:1.In contrast,a 1:1initial mass ratio of sucrose:actin was suf®cient for air drying,which does not have the need for protein stabilization prior to dehydration.38A relatively low initial concentration of sucrose is suf®cient to stabilize a protein during drying because sucrose inhibits dehydration-induced unfolding by repla-cing the hydrogen bonds between the protein and water,which are lost upon water removal.9,10,13Under conditions used in the current study,anti-L-selectin did not appear to be freeze labile,and by including as little as 0.125%sucrose (0.5:1sucrose:protein mass ratio),anti-L-selectin in the dried solid had essentially native b -sheet struc-ture.When freeze-thaw labile proteins (e.g.,rFXIII,actin,lactate dehydrogenase)were lyo-philized,much higher sugar concentrations or the addition of a cryoprotectant (e.g.,polyethylene glycol)was necessary to inhibit lyophilization-induced unfolding maximally.2,5,10,12,13,38Thus,only protection against dehydration stress was needed to prevent lyophilization-induced unfold-ing of the anti-L-selectin.During lyophilization,the presence of Tween 20alone only partially inhibits loss of native b -sheet structure.Because no evidence of freeze-thaw lability is observed for the anti-L-selectin,Tween is likely providing some protection during drying.Tween 20might be preventing some puta-tive surface-mediated damage during drying,but the mechanisms for this protection are not clear.Effect of Formulation on Protein Stability During Lyophilization and Reconstitution in Water Preservation of native protein secondary struc-ture during lyophilization usually results in na-tive protein upon reconstitution because the protein does not need to alter its conforma-tion.13,32Unfolded protein in thefreeze-driedFigure 2.(A)Representative chromatogram and curve ®t of reconstituted anti l-selectin (anti-L-selectin lyophilized in buffer and reconstituted with 1%sucrose).The actual chromatogram is displayed as a solid line.The curve ®ts are as follows:dotted line:oligomer;dashed line:dimer;long-dashed line and dashed-double dotted line:monomer;and dashed-dotted line:total curve ®t.(B)Chromatogram of control.1472JONES ET AL.JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER 2001solid does not necessarily result in nonnative protein because recovery of native protein mole-cules upon reconstitution is largely governed by the kinetic competition between protein refolding and aggregation.3In dried formulations where most of the native secondary structure is pre-served,some aggregates can still be formed from a small fraction of the protein population that has perturbed secondary or tertiary structure.Thus,even for formulations with apparent maximal inhibition of lyophilization-induced perturbations of secondary structure,it may be necessary to employ conditions that inhibit aggregation during reconstitution to optimize recovery of native protein.As expected,based on the IR spectra of the dried samples,anti-L-selectin lyophilized in the presence of sucrose contains the least amount of aggregates after reconstitution with water.Nevertheless,even the formulations with the highest degree of native b -sheet structure in the dried solid still have detectable oligomers after reconstitution with water (Figure 2B).This result is consistent with that of Ressing et al.,who found a 10%loss of activity of mouse IgG MN12lyophilized in either the presence or absence of stabilizers,including sucrose,when reconstituted immediately with water.39In the present study,both sucrose formulations required 0.1%Tween 20in the reconstitution solution to prevent oligomer formation and reduce dimers to control levels.Lyophilization from Tween 20solutions results in more aggregation of anti-L-selectin than lyo-philization in buffer alone.Sarciaux et al.found with bovine IgG that the presence of Tween 80in the lyophilized formulation reducedturbidityFigure 3.Aggregate content of reconstituted sam-ples.The reconstitution solution,water or excipient in water,is given on the x-axis.Filled bars:dimer.White bars:oligomer.Results are means ÆSD for triplicate samples (A)Anti-L-selectin freeze dried in buffer.(B)Anti-L-selectin freeze dried in buffer containing sucrose.(C)Anti-L-selectin freeze dried in buffer containing 0.1%Tween 20.(Note:the symbols indicate statistical signi®cance using Student's t -test with a 95%con®dence interval.*Signi®cantly different from the control. For a given lyophilization formulation,recon-stitution with the excipient solution yields signi®cantly different results than reconstituting with water.#For the given reconstitution solution,the result is signi®-cantly different from samples lyophilized in the pre-sence of buffer alone.)TWEEN 20,SUCROSE,AND ANTI-L-SELECTIN 1473JOURNAL OF PHARMACEUTICAL SCIENCES,VOL.90,NO.10,OCTOBER 2001。

对乙酰氨基酚含有能抑制口腔感到苦涩和改进咀嚼片

International Journal of Pharmaceutics 278(2004)51–61Acetaminophen-containing chewable tablets with suppressedbitterness and improved oral feelingHiroyuki Suzuki a ,Hiraku Onishi a ,∗,Seiji Hisamatsu a ,Kosuke Masuda a ,Yuri Takahashi a ,Masanori Iwata b ,Yoshiharu Machida aaDepartment of Drug Delivery Research,Hoshi University,2-4-41,Ebara,Shinagawa-ku,Tokyo 142-8501,Japanb Department of Pharmacy,Yokohama City University Medical Center,4-57,Urafune-cho,Minami-ku,Yokohama City,Kanagawa 232-0024,JapanReceived 30August 2003;received in revised form 25January 2004;accepted 14February 2004AbstractThe aim of this study was to develop acetaminophen chewable tablets with suppressed bitterness and improved oral feeling by examination of hard fats as the matrix base and of sweetening agents as corrigents.Witepsol ®H-15,W-35,S-55,E-75and E-85,and Witocan ®H and 42/44were used as hard fats.Witocan ®H and 42/44were selected in view of improved oral feeling.Witocan ®H/Witocan ®42/44mixture tablets showed different melting characteristics and drug release rates dependent on their ratios,and those with the Witocan ®H/Witocan ®42/44ratio of 92.5%(w/w)and more showed good drug release.Sucrose,xylitol,saccharin,saccharin sodium,aspartame and sucralose were used as sweetening agents,and applied alone or with Benecoat BMI-40or cocoa powder.The Witocan ®H tablet with 1%(w/w)saccharin plus 5%(w/w)Benecoat BMI-40(Sc1-B5),and the Witocan ®H/Witocan ®42/44(92.5:7.5,w/w)mixture tablet with 1%(w/w)aspartame plus 5%(w/w)Benecoat BMI-40suppressed bitterness and sweetness excellently,but the former tablet showed better drug release.Thus,the Witocan ®H tablet with Sc1-B5is suggested as the best acetaminophen chewable tablet,exhibiting suppressed bitterness,low sweetness,improved oral feeling and good drug release.©2004Elsevier B.V .All rights reserved.Keywords:Acetaminophen chewable tablet;Hard fat;Bitterness;Sweetness;Oral feeling;Drug release1.IntroductionMany drugs exhibit bitter taste when orally admin-istered (Nakamura et al.,1990;Shirai et al.,1993,1994;Katsuragi et al.,1995;Yajima et al.,1999),and the bitter taste often causes non-compliance of patients because of the discomfort (Uchida,2002).Therefore,suppression of the bitter taste has been an important∗Corresponding author.Tel.:+81-3-5498-5760;fax:+81-3-5498-5760.E-mail address:onishi@hoshi.ac.jp (H.Onishi).subject for oral dosage forms.Various methods such as capsules,drug coating,microencapsulation,com-plexation and chemical modiﬁcation have been uti-lized to improve the bitter taste (Nakamura et al.,1990;Shirai et al.,1993,1994;Yajima et al.,1999).How-ever,these techniques are not always useful or appli-cable;for example,capsules or coated tablets are of-ten uncomfortable for infants or elderly people,who have trouble in swallowing drugs,due to their bulki-ness.Further,the approaches such as drug coating,mi-croencapsulation,complexation and chemical modiﬁ-cation are not necessarily simple,and extensive opti-0378-5173/$–see front matter ©2004Elsevier B.V .All rights reserved.doi:10.1016/j.ijpharm.2004.02.03152H.Suzuki et al./International Journal of Pharmaceutics278(2004)51–61mization is required for their practical use.Therefore, the dosage forms which can be produced simply and that the patients can swallow easily may be important and valuable for the masking of the drug taste.The simple way to achieve such dosage forms is to add ap-propriate masking agents to power,liquid or chewable dosage forms(Popova,1969;Katsuragi and Kurihara, 1993;Katsuragi et al.,1995,1996,1997;Yin et al., 1996;Ishikura et al.,2002;Takano,2002).As to eval-uation of taste intensities including bitterness,the sen-sation tests by human volunteers have been utilized (Indow,1966,1969).An alternative method using a taste sensor have been recently studied because it may permit the examination of dangerous compounds or complete the tests of many substances in a short time (Uchida et al.,2000,2001;Uchida,2002).However, since mechanism of taste sensation is complicated,the sensation tests by human volunteers appear to be still a very useful method to determine the taste intensities. Acetaminophen,an antipyretic,has a bitter taste, but is often applied to infants and children due to its safety,when suppository and syrup dosage forms are often used to take the drug more comfortably(Autret et al.,1994;Van Esch et al.,1995;Coulthard et al., 1998;Hansen et al.,1999).Suppository insertion re-quires a private space at the administration.In drinking the syrup,a fairly large volume of the liquid and the sweet taste are sometimes a burden for the patients. Actually,in the preliminary studies,we tested tastes about three commercial syrups of acetaminophen,but they exhibited fairly strong sweetness and did not sup-press the bitterness very much.To improve these mat-ters,we had developed the acetaminophen-containing chewable tablets using Witepsol®H-15or cacao butter as a matrix base and some corrigents as bitter masking agents(Suzuki et al.,2003).These chewable tablets could be prepared simply,and were considered to be available to patients having trouble in swallowing be-cause they could be chewed.However,these tablets did not necessarily show comfortable oral feeling,which appeared to be mainly due to the stickiness of the hard fat.Therefore,further examination of the formulations was required to improve oral feeling in addition to bitterness suppression.In the present study,various kinds of hard fats and many sweetening agents were examined to obtain acetaminophen chewable tablets with suppressed bitter taste and improved oral feel-ing.The dose of acetaminophen per oral administra-tion was300–500mg for adults,but it was adjusted to10mg/kg for infants.Furthermore,it is not difﬁcult to take some chewable tablets at a time.Considering these features,the drug content of the chewable tablet was set at100mg as reported previously.In the present study,as to hard fats,Witocan®was examined in addition to Witepsol®;Witocan®is utilized as special hard fats in the chocolate and con-fectionery industry.Currently available sweetening agents,that is,sucrose,xylitol,saccharin,saccharin sodium,aspartame and sucralose,were used as sweet-ening agents(Japan Food Additives Association, 2001).They show different sweet taste intensities and oral feeling.Xylitol has a sweet taste intensity similar to sucrose but gives a brisk feeling orally.Saccharin and saccharin sodium are500times as sweet as su-crose,and aspartame and sucralose showed200and 600times as the sweet taste intensity as sucrose,re-spectively.In addition to the above sweetening agents, commercial bitter-masking powder mixture made from lecithin(Benecoat BMI-40)(Katsuragi et al., 1997)and cocoa powder(Koyama and Kurihara, 1972;Pickenhagen et al.,1975;Aremu et al.,1995) were utilized as corrigents.As shown in the previ-ous report,the corrigent systems of1or5%(w/w) sucrose plus5%(w/w)Benecoat BMI-40,or1% (w/w)sucrose plus1%(w/w)cocoa powder,or5% (w/w)sucrose alone gave the best suppression of the bitter taste intensities of acetaminophen-containing Witepsol®H-15chewable tablets(Suzuki et al., 2003).Therefore,in the present study,acetaminophen chewable tablets were prepared at the similar con-ditions;that is,they were prepared using hard fats with1or5%(w/w)sweetening agent plus5%(w/w) Benecoat BMI-40,or1%(w/w)sweetening agent plus1%(w/w)cocoa powder,or5%(w/w)sweeten-ing alone.The obtained tablets were evaluated based on suppression of bitter taste,sweet taste intensity, oral feeling and drug release.2.Materials and methods2.1.MaterialsAcetaminophen was purchased from Sigma Chem-ical Co.(USA).Quinine sulfate,sucrose,saccharin, saccharin sodium,xylitol,aspartame and sucraloseH.Suzuki et al./International Journal of Pharmaceutics 278(2004)51–6153were purchased from Wako Pure Chemical Industries,Ltd.(Japan).Hard fats (Witepsol ®H-15,W-35,S-55,E-75and E-85,Witocan ®H and 42/44)were pur-chased from Mitsuba Trading Co.(Japan).Commer-cial bitter-masking powder mixture made from lecithin (Benecoat BMI-40)was supplied from Kao Corpora-tion (Japan).For cocoa powder,a commercial product was used.All other chemicals were of reagent grade.2.2.Preparation of chewable tabletsAll the chewable tablets (1g)containing 100mg of acetaminophen were prepared based on the following casting method:A hard fat or a mixture of hard fats was put in a glass beaker and melted by warming at 45◦C on a water bath.Acetaminophen and/or corri-gents were added,the mixture was stirred quickly with a glass bar,then 1g of the mixture was poured into a mold to yield a disk-shaped tablet (2cm diameter).The types of chewable tablets described in Table 1were prepared,and their use and features are in the following.2.2.1.Formulation AThis type of chewable tablet was prepared to ex-amine the effect of kinds of hard fats on bitter taste and oral feeling of the chewable tablet.The chewable tablets with various hard fats as a matrix base using sucrose and Benecoat BMI-40each at 5%(w/w)as corrigents were prepared.2.2.2.Formulation BThis type of chewable tablet was prepared to ex-amine the effect of the Witocan ®H/Witocan ®42/44Table 1Formulations and compositions of the chewable tablets (1g)Formulation Composition [weight ratio]A Hard fat/acetaminophen/sucrose/Benecoat BMI-40[80/10/5/5]B Witocan ®H–Witcan ®42/44mixture/acetaminophen [9/1]C-1Witocan ®H/acetaminophen/sweetening agent [85/10/5]C-2Witocan ®H/acetaminophen/sweetening agent/Benecoat BMI-40[80/10/5/5]C-3Witocan ®H/acetaminophen/sweetening agent/Benecoat BMI-40[84/10/1/5]C-4Witocan ®H/acetaminophen/sweetening agent/cocoa powder [88/10/1/1]D-1Witocan ®H–Witcan ®42/44mixture (92.5:7,w/w)/acetaminophen/saccharin [85/10/5]D-2Witocan ®H–Witcan ®42/44mixture (92.5:7,w/w)/acetaminophen/saccharin/Benecoat BMI-40[84/10/1/5]D-3Witocan ®H–Witcan ®42/44mixture (92.5:7,w/w)/acetaminophen/saccharin/cocoa powder [88/10/1/1]D-4Witocan ®H–Witcan ®42/44mixture (92.5:7,w/w)/acetaminophen/aspartame/Benecoat BMI-40[84/10/1/5]ratio on melting temperature and drug release rate.A mixture of Witocan ®H and Witocan ®42/44(80:20,85:15,90:10,92.5:7.5,95:5,97.5:2.5or 100:0,w/w)was used as a matrix base.No corrigent was added.2.2.3.Formulations C-1,C-2,C-3and C-4These chewable tablets were prepared to investi-gate the effect of sweetening agent on bitterness and sweetness of the Witocan ®H chewable tablets.Su-crose,xylitol,saccharin,saccharin sodium,aspartame and sucralose were used as sweetening agents.The four kinds of corrigent systems described in Table 1were examined.2.2.4.Formulations D-1,D-2,D-3and D-4These chewable tablets were prepared using the Witocan ®H/Witocan ®42/44mixture (92.5:7.5,w/w)as a matrix.The four kinds of corrigent systems de-scribed in Table 1were examined.In all the tablets prepared,the amount of the sweet-ening agent per tablet was much lower as compared with the acceptable daily intake (Japan Food Additives Association,2001).2.3.Measurement of intensities of bitterness and sweetnessBitter and sweet taste intensities were determined by the sensation tests using healthy men with age of 21–25based on the methods by Indow (1966,1969)and Katsuragi et al.(1997).Before measurement,in-formed consent was completed to each volunteer.Qui-nine aqueous solutions with a series of concentrations were prepared as standard solutions of bitter taste in-tensities,and the intensities were deﬁned from 0to 1054H.Suzuki et al./International Journal of Pharmaceutics278(2004)51–61 Table2Relationship between deﬁned taste intensity and concentration ofquinine sulfate or sucrose aqueous solutionDeﬁned taste intensity Quinine sulfateconcentration forbitterness(%,w/v)Sucroseconcentration forsweetness(%,w/v)00.000000.010.00023 1.020.00050 1.930.00094 3.040.00157 4.350.00241 6.460.003889.070.0060814.080.0098522.590.0157224.0100.0256878.0(Table2).Also,sucrose aqueous solutions with a se-ries of concentrations were used as standard solutions for measurement of sweet taste intensities,when the intensities were deﬁned from0to10(Table2).The bitter or sweet taste intensities of chewable tablets were evaluated as follows:1ml of each stan-dard solution was dropped on the center of the tongue, the solution was retained in the mouth for10s,then the mouth was rinsed thoroughly with de-ionized wa-ter so that recognition of the taste intensities of the standards was recovered.At10min after remember-ing the taste intensities of each standard solution,the mouth was rinsed fully again,one tablet was put in the mouth,chewed10times and retained on the center of the tongue in the mouth for10s.At that time,the sub-ject decided the taste intensity of the chewed tablet by comparison with that of each standard solution.For examination of the taste intensities of bitterness and sweetness,the number of the subjects in each group was three.2.4.Drug release testsThe drug release was generally examined for in-tact tablets.As to the chewable tablets selectedﬁnally, both intact and crushed tablets were examined for drug release.Crushed tablets were prepared by breaking a tablet mechanically into nearly10pieces with similar fragment size to simulate the fragmentation of a tablet by chewing.The drug release experiment was per-formed according to theﬁrst method(rotation basket method)of the dissolution test in the Pharmacopoeia of Japan(JP)14.Theﬁrstﬂuid,aqueous HCl solution containing NaCl at0.2%(w/v)(pH1.2)and the second ﬂuid,50mM phosphate buffer(KH2PO4–NaOH)(pH 6.8)of the disintegration test in the Pharmacopoeia of JP14were used as release media.One tablet or all the fragments obtained by crushing one tablet were put in a basket,immersed completely in900ml of the disso-lution medium pre-warmed at37±0.5◦C so that the basket bottom was located at2.5cm from the inner bottom of the container,and rotated at60rpm at37±0.5◦C.At appropriate time points,1ml of the tested medium was taken andﬁltered with a membraneﬁlter (0.45␮m pore size).Immediately after each sampling, 1ml of fresh medium was complemented.Theﬁltrate was diluted10-fold in volume with fresh medium,and measured spectrophotometrically at244nm to deter-mine the amount of released drug.In each drug re-lease test performed,hard fats and corrigents showed no inﬂuence on the determination of acetaminophen concentration by this method.2.5.Measurement of melting characteristics of chewable tabletsThe melting features of chewable tablets were ex-amined by differential scanning calorimetry(DSC)us-ing a Rigaku THERMOFLEX TAS200DAS8230D (Japan).The tablets were roughly crushed,and the ob-tained particles of10mg were used as a sample.The DSC scan speed and scan range were5◦C/min and 25–50◦C,respectively.The temperature of the mini-mum peak of the endothermic DSC curve was deﬁned as a melting temperature of the tablet.2.6.Statistical analysisFor the comparison,statistical analyses were per-formed using the unpaired t-test.The results at P< 0.05was regarded as signiﬁcantly different.3.Results and discussion3.1.Effect of kinds of hard fats on bitterness and oral feelingAll the tablets were obtained in a disk shape with 2cm in diameter and4–5mm in thickness.ThoseH.Suzuki et al./International Journal of Pharmaceutics278(2004)51–6155 Table3Melting properties of various hard fats and bitter taste and oral feeling of their acetaminophen-containing tablets with sucrose and Benecoat BMI-40each at5%(w/w)as corrigentsCommercial name of hard fat Grade Melting point(◦C)a Bitter tasteintensity bOrder of oralfeeling cWitepsol®H-1533.5–35.5 5.2±0.47W-3533.5–35.57.0±0.06S-5533.5–35.58.2±0.3∗4E-7538 5.0±0.05E-8542–44 5.0±0.62Witocan®H33.5–35.5 5.0±0.0342/4442–44 4.5±0.31a These melting points were shown by the suppliers.b The bitter taste intensity was determined based on the recognition by human volunteers stated in Section2.3in the text and the result is as the mean±S.E.(n=3).c Smaller number exhibited better oral feeling in the tablets.∗Signiﬁcant difference,P<0.05vs.Witepsol®H-15.tablets were a little harder than solid chocolate,but they could be easily crushed by bite,though their hardness was not measured in detail.Formulation A was used in this ly,various hard fats were used as a matrix,and5%(w/w)Benecoat BMI-40plus5%(w/w)sucrose were used as corri-gents.The commercial name and melting point of the hard fats applied are described in Table3.The bitter taste intensities were approximately5for Witepsol®H-15,E-75and E-85,and Witocan®H.Witepsol®W-35and S-55exhibited higher bitter taste intensities of7–8.2.Witocan®42/44showed the lowest bitter taste intensity of4.5.Only the Witepsol®S-55exhib-ited a signiﬁcantly higher bitter taste intensity differ-ent from Witepsol®H-15(P<0.05).The oral feeling of the chewable tablets was related mainly to sticki-ness to the oral cavity and gingival,and that sensation was ranged in the order of more comfortable feeling as shown in Table3.Overall,the bitter taste intensities of less than5–6were tolerable,and the oral feelings of the order1–3were acceptable.Thus,the Witocan®H and42/44tablets were adequate as tablets with suppressed bitterness and improved oral feeling.Al-though the Witocan®42/44tablet exhibited bitterness suppression and oral feeling best,the release percent-ages were less than6%in both theﬁrst and second ﬂuids even at2h after start of the release test(data not shown).The poor drug release was considered to be due to higher melting point of Witocan®42/44,and also the good bitterness suppression might be due to the low drug release.Thus,Witocan®H or the mixture of Witocan®H and Witocan®42/44,which showed lower melting points,were used in the following ex-periments.3.2.Effect of the Witocan®H/Witocan®42/44ratio on melting temperature and drug release Formulation B was used in this experiment. Witocan®H alone and the mixture of Witocan®H and Witocan®42/44were applied as a matrix base, and the obtained tablets were examined for melting temperature and drug release extent.Effect of the Witocan®H/Witocan®42/44ratio on melting tem-perature is shown in Table4.The meting temperature rose with the decrease of the Witocan®H/Witocan®42/44ratio.The drug release proﬁles of the chew-able tablets with different Witocan®H/Witocan®42/44ratios are described in Fig.1.The chewable Table4Melting temperature of chewable tablets with different Witocan®H/Witcan®42/44ratiosWitocan®H/Witcan®42/44ratio(w/w)Melting temperature(◦C)(mean±S.D.) 100/038.5±0.397.5/2.538.9±0.195/539.2±0.292.5/7.539.2±0.190/1039.8±0.585/1540.3±0.180/2041.0±0.156H.Suzuki et al./International Journal of Pharmaceutics 278(2004)51–61Fig.1.Release proﬁles of acetaminophen from tablets prepared using Witocan ®H alone or Witocan ®H/Witocan ®42/44mixture as a base.The intact tablets were used in the experiment.(A)First ﬂuid in JP 14;(B)second ﬂuid in JP 14.(᭿)100%(w/w)Witocan ®H;(᭜)97.5%(w/w)Witocan ®H;(᭹)95%(w/w)Witocan ®H;(᭡)92.5%(w/w)Witocan ®H;()90%(w/w)Witocan ®H;()85%(w/w)Witocan ®H;(⊕)80%(w/w)Witocan ®H.Each point represents the mean ±S .D.(n =3).tablets with the Witocan ®H/Witocan ®42/44ratios of 92.5%(w/w)or more showed good drug release.When the drug release extent was evaluated by the percentage of the drug released from the intact tablet at 2h after the start of the release test,the relation-ship between melting temperature anddrug release extent was obtained as shown in Fig.2.These results indicated that the chewable tablet made of Witocan ®H alone exhibited the lowest melting temperature and best drug release.The chewable tablets with the Fig.2.Relationships between melting temperature and acetaminophen release extent for the Witocan ®H/Witocan ®42/44mixture tablets.(A)Melting temperature vs.percent released in the ﬁrst ﬂuid in JP 14at 2h after the start of the test;(B)melting temperature vs.percent released in the second ﬂuid in JP 14at 2h after the start of the test.The melting temperature was deﬁned as the temperature of the minimum peak of the endothermic DSC proﬁle.Each point represents the mean ±S .D.(n =3).Witocan ®H/Witocan ®42/44ratios of 10%(w/w)or more exhibited poor drug release.The mixed base of 92.5%(w/w)Witocan ®H and 7.5%(w/w)Witocan ®42/44gave good release extent in only the second ﬂuid.The release extent decreased sharply in a reverse sigmoidal curve around the melting temper-ature of 39.2◦C.These suggested that the Witocan ®H/Witocan ®42/44mixture must contain Witocan ®H at 92.5%(w/w)or more to achieve sufﬁcient release of acetaminophen.H.Suzuki et al./International Journal of Pharmaceutics278(2004)51–6157Fig.3.Bitter and sweet taste intensities of Witocan®H chewable tablets with various corrigent systems.No Corr,with no corrigent;Sr, sucrose;B,Benecoat BMI-40;Cp,cocoa powder;X,xylitol;Sc,saccharin;Ss,saccharin sodium;A,aspartame;Sl,sucralose.The number attached to the corrigent abbreviation showed the percentage of the corrigent in the chewable tablet;for example,Sr5-B5means the corrigent system of5%(w/w)sucrose and5%(w/w)Benecoat BMI-40.()Bitter taste intensity;()sweet taste intensity.Each column represents the mean±S.E.(n=3).For bitter taste intensities,the corrigent systems except X5,Sc5-B5and A5-B5were signiﬁcantly different from No Corr(P<0.05).3.3.Effect of sweetening agents on bitter and sweet taste intensities of chewable tabletsFormulations C-1,C-2,C-3and C-4were used in this experiment,and the bitter and sweet taste intensi-ties of the chewable tablets were examined.The bitter and sweet taste intensities of the chewable tablets are shown in Fig.3.The chewable tablet with no corri-gent showed the bitter taste intensity of7.2.In com-parison with the chewable tablet with no corrigent, the other chewable tablets showed signiﬁcantly lower bitterness(P<0.05)for the corrigent systems other than5%(w/w)xylitol(X5),5%(w/w)saccharin plus 5%(w/w)Benecoat BMI-40(Sc5-B5),and5%(w/w) aspartame plus5%(w/w)Benecoat BMI-40(A5-B5). Saccharin and its sodium salt tended to suppress bit-ter taste more than sucrose.Sweet taste became much higher in saccharin sodium but increased slightly in saccharin,which was probably because saccharin sodium is easily soluble than saccharin.As a whole,the tablets using saccharin as a sweetening agent showed good balance in bitter and sweet tastes.In particular,the corrigent system of1%(w/w)saccha-rine plus5%(w/w)Benecoat BMI-40(Sc1-B5)was excellent.Although several tablets with aspartame or sucralose as a sweetening agent inhibited bitterness much more than those with sucrose,they gave much sweeter taste than sucrose.Aspartame and sucralose can suppress bitter taste effectively due to their highly sweetening potential,but high increase in the sweet taste intensity appeared to cause discomfort in taking the tablets;generally,the samples with the sweet taste intensities of four or more were too sweet to take.In the preliminary study,three kinds of commer-cial syrups of acetaminophen,being prescription drugs (commercial name not described),were examined on bitterness and sweetness(n=3).Two(theﬁrst and second syrups)include saccharin sodium as a sweet-ening agent,and the other(the third syrup)contains aspartame as a sweetening agent.Their tastes were58H.Suzuki et al./International Journal of Pharmaceutics278(2004)51–61examined in the manner as stated previously(Suzuki et al.,2003);namely,the syrups were tasted in the same manner as the standard solution.As a result,the ﬁrst syrup exhibited the bitter and sweet taste intensi-ties of4.2and5.2,respectively.The second showed the bitter and sweet taste intensities of5.2and5.3,re-spectively,and the third exhibited the bitter and sweet taste intensities of4.3and5.7,respectively.Theﬁrst syrup showed the best tastes.The Witocan®H chew-able tablet with Sc1-B5exhibited the bitter taste in-tensity of4and the sweet taste intensity of1.5,indi-cating that this tablet suppressed taste intensities bet-ter,especially sweetness,as compared with the above commercial syrups.3.4.Taste intensities and drug release for the Witocan®H/Witocan®42/44(92.5:7.5,w/w)mixture tabletsThe Witocan®H chewable tablets improved oral feeling,but the addition of Witocan®42/44can im-prove the oral feeling more.Based on the results in Figs.1and2,the Witocan®H/Witocan®42/44 (92.5:7.5,w/w)mixture tablets,exhibiting good drug release,were chosen.The mixture tablets were pre-pared for the excellent corrigent systems in Fig.3; that is,D-1,D-2,D-3and D-4in Table1were pre-pared.They were examined for taste intensities and drug release.The results of taste intensities are shown in Fig.4. The bitter taste intensity of the chewable tablet with no corrigent was6.2.For each corrigent system,the taste intensities were almost parallel to those in Witocan®H tablets.The corrigent systems except Sc1-B5showed signiﬁcant suppression of bitterness(P<0.05).In particular,A1-B5exhibited the least bitter taste inten-sity and low sweetness.The drug release proﬁles of the intact tablets are shown in Fig.5.All the tablets showed good drug release.3.5.Drug release from intact and crushed tablets For the tablets showing excellent taste balance in the Witocan®H tablets(Fig.3)and Witocan®H/Witocan®42/44(92.5:7.5,w/w)mixture tablets (Fig.4),the drug release tests were performed at the intact and crushed conditions.That is,the Witocan®H tablet with Sc1-B5and Witocan®H/Witocan®Fig.4.Bitter and sweet taste intensities of Witocan®H/Witocan®42/44(92.5:7.5,w/w)mixture chewable tablets with several corri-gents.The abbreviation and expression of corrigent systems were the same as in Fig.3.()Bitter taste intensity;()sweet taste intensity.Each column represents the mean±S.E.(n=3).For bitter taste intensities,the corrigent systems except Sc1-B5were signiﬁcantly different from No Corr(P<0.05).42/44(92.5:7.5,w/w)mixture tablet with A1-B5were selected,and their drug release was examined in the intact and crushed forms.The results are shown in Fig.6.The Witocan®H tablet with Sc1-B5showed good release in both intact and crushed forms;that is,more than50%(w/w)of the drug was released in the secondﬂuid at2h after the start of the release test.In particular,this tablet showed that the crushed form released approximately50%of the drug in the secondﬂuid at1h after the start of the release test. The Witocan®H/Witocan®42/44(92.5:7.5,w/w) mixture tablet with A1-B5showed good release in the intact form,but not in the crushed form.These results were possibly related to the melting properties of the ly,the Witocan®H tablet with Sc1-B5melted completely to form liquid droplets during the release test,especially in the secondﬂuid. On the other hand,for the Witocan®H/Witocan®42/44(92.5:7.5,w/w)mixture tablet with A1-B5,soft semisolid remained on the basket after the release test;an aggregated and bulky semisolid was formed markedly in the crushed form,probably leading to poor drug release.These features were consistent with the results in Fig.2that the Witocan®H/Witocan®。

影响美拉德反应的几种因素研究

到 25 ℃测定吸光度，室温分别放置 4 h 和 24 h，并测定其相应吸光度。
进行。因此，在这样的条件下美拉德反应不显著。 (2)在碱性条件下，由于邻近 n 原子的影响，糖碱
1.3.3 赖氨酸与不同浓度和不同种类糖的反应分别称取适量的赖氨酸和 5 种糖，用 pH＝10.0
基 C1 上电子密度增大，使 1,2-烯醇化转为困难，所以在碱性介质中，一般进行 2,3-烯醇化。
441
现代食品科技
Modern Food Science and Technology
2010, Vol.26, No.5
用棕色瓶置于暗处储存备用。吸取一定量的反应液于具塞试管中，在温度为 100 ℃水浴中加热时间 1 h。反应结束即用水冷却到 25 ℃测其吸光度。
增加，在 pH＝8.0 和 pH＝10.0 出现两个突变点，而 pH＝9.0~10.0 相对变化较小，pH＝11.0~12.0 趋于稳定。pH 对美拉德反应的影响，其原因一般认为[7-9]：
复取平均值。
2 结果与讨论
图 2 温度和时间对美拉德反应的影响 Fig.2 Effect of temperature and time on Maillard reaction
2.1 不同 pH 对反应的影响
由图 2 可见，不同温度加热相同时间的吸光度不
由图 1 可见，美拉德反应在 pH 为 5.0~7.0 时，其同。总体来说，吸光度随温度的升高而增加，随加热
的缓冲液分别定容至 0.1 mol来自L。取糖溶液 2 mL、4 mL、
6 mL、8 mL 分别加入 4 支试管中，再往每支试管中
加入 0.1 mol/L 的赖氨酸溶液 2 mL，最后加入一定量
缓冲溶液，使反应体系达到 10 mL，调 pH=10.0，将试管置于 100 ℃水浴中加热，40 min 后取出，冷却到

冷冻干燥参数对塌陷温度的影响分析

收稿日期: 2010 04 30 修回日期: 2010 05 31 * 国家自然科学基金资助项目 ( 50736001) 和辽宁省科学技术基金资助项目 ( 2007010124) 作者简介: 左建国, 副教授, 主要从事冷冻干燥和传热传质研究, E m ai:l jgzuo@ d lut. edu. cn
为了研究压力对塌陷温度的影响, 对于 10% 蔗糖水溶液, 分别采用不同的升华压力, 结果如表 2所
12 8
农业机械学报
2 0 1 1年
示。从表中可以看出, 压力在 0 5~ 100 P a范围内变化时, 塌陷温度变化很小。考虑到测量误差, 可以认为压力对塌陷温度没有影响。
表 2 压力对 10%蔗糖水溶液塌陷温度 T c 的影响 Tab. 2 E ffec t of p ressure on the collap se tem perature T c
另外随着蔗糖溶液质量分数增大冰晶逐渐减小25蔗糖水溶液的冻干图像相比冻结区的冰晶更加细干燥区和冻结区结构都保持完好没有塌陷发生干燥区贴近升华界面处发生微塌陷局部出现了小的孔洞着温度不断升高孔洞逐渐变大并连成一片干燥区靠近升华界面处整体都发生了塌陷pressurecollasetemperaturetcsucrosesoluion压力pa01510100tc3112213溶液质量分数冻干溶液通常为低质量分数溶液10蔗糖溶液的塌陷温度3717
F reeze drying m icroscopy w as used to investigate the effect of freezing ra te, pressure and m ass fraction on the co llapse tem perature ( T c ) during freeze dry ing of aqueous solutions, and d ifferent ia l scanning calorim e try w as used to investigate the g lass transit ion tem perature (T g!) of the m ax im ally freeze concentrated so lut ion. The experim enta l results show ed that for 10% sucrose /w ater b inary solution, the freezing rate had little effect on T c although it cou ld affect the size of ice crystals. For 10% tertiary buty l alcoho l /10% sucrose /w ater ternary so lution, both Tg! and T c decreased w ith the increase of freezing rate. F ew variations in collapse tem peratures cou ld be expected when vary ing the pressure. Fo r sucrose aqueous solutions at different m ass fract ions ( 5% ~ 25% ), the varia tion o f co llapse tem perature w as less than 1∀ .

浸泡_蒸煮工艺对大豆品质特性的研究_李次力

浸泡、蒸煮工艺对大豆品质特性的研究李次力(哈尔滨商业大学食品工程学院,哈尔滨150076)摘要对大豆浸泡、蒸煮等预处理工艺条件进行了研究。

结果表明,浸泡工艺最佳条件:在25e下,豆水按照比例1B3,浸泡时间为12h,大豆的完全吸水率可达到2.1。

使用物性仪分别测定了不同蒸煮温度和时间下大豆的硬度、弹性、咀嚼性,发现其中硬度、弹性、咀嚼性随温度的升高而逐渐下降,而脆性变化无明显规律。

大豆的前处理最佳工艺条件:蒸煮温度为112e,豆水为1B1.2,蒸煮时间为25min。

关键词大豆浸泡蒸煮品质大豆含有丰富的蛋白质,营养价值高。

还含有黄酮类、磷脂、皂苷、低聚糖、豆甾醇等功能性物质,是冠心病、高血压、动脉硬化病人的理想食品[1-3]。

采用乳酸菌发酵大豆能使蛋白质、脂肪和糖类分解为人体更易吸收的预消化状态,同时还能增加可溶性钙、磷、铁和某些B族维生素的含量,提高它的消化吸收性能和营养价值[4-6]。

本文主要对采用乳酸菌发酵大豆的前预处理工艺进行研究,研究了大豆的吸水率及温度对大豆浸泡工艺的影响,并利用物性仪探讨了大豆培养基蒸煮灭菌工艺的最佳方案。

1材料与方法1.1主要材料大豆:黑龙江省农科院提供,颗粒饱满,无霉变。

1.2仪器物性仪TX-ZI:英国;电热手提式压力蒸汽消毒器YXQ.SG46.280型:哈尔滨松花江医疗机械厂;电热恒温培养箱HH.B11.360型:天津市实验仪器厂;干热灭菌箱603-1型:大连第四仪器厂;生物显微镜YS2-H型:Nikon公司。

1.3大豆浸泡工艺的研究1.3.1大豆吸水率的研究除去原料大豆表面的尘土和杂质,清洗干净,将大豆放在三倍体积的水中进行浸泡。

主要目的是软化大豆的细胞结构,提高胶体的分散性和悬浮状态[7]。

浸泡适度的大豆蛋白体膜呈松脆状态,有利基金项目:哈尔滨市科技攻关计划项目(2004AA3CN158)收稿日期:2007-08-10作者简介:李次力,男,1963年出生,副教授,食品科学与工程于营养物质的溶出,并有助于乳酸发酵时乳酸菌更好地利用大豆的营养成分。

咖啡烘焙过程的基本化学反应中英双语

咖啡烘焙过程的基本化学反应中英双语展开全文原文：Basic Chemical Reactions Occurring in the Roasting Process by Carl Staubsourced from the SCAA Roast Color Classification System developed by Agtron - SCAA in 1995Many thermal and chemical reactions occur during the roasting process: decarboxylation, dehydration of quinic acid moiety, fractionization, isomerization, polymerization, and complex sugar reactions. The principal thermally reactive components are monosaccharides and sucrose, chlorogenic acids, free amino acids, and trigonelline. Both aravinose and calactose of polysaccharides are splitoff and the basic sulfur containing and hydroxyamino acids decompose. Carbohydrates both polymerize and degrade, liberating thermally unstable monosaccharides decomposing 20-30% of the polysaccharides, depending on the degree of roast.Sucrose: Disaccharide of d-Glucosyl and d-Fructosyl Moieties Sucrose is the principle sugar in coffee. The melting point of pure crystalline sucrose is in the 320-392 degrees F with 370 degrees F most commonly accepted. Degradation of dry sucrose can occur as low as 194 degrees F. and begins with the cleavage of the glycosidic bond followed by condensation and the formation of water. Between 338 and 392 degrees F, carmelization begins. It is at this point that water and carbon dioxide fracture and out-gassing begins causing the first mechanical crack. These are the chemical reactions, occurring atapproximately 356 degrees F, that are exothermic. Once carmelization begins, it is very important that the coffee mass does not exotherm (lose heat) or the coffee will taste "baked" in the cup. A possible explanation is that exothermy of the charge mass interrupts long chain polymerization and allows cross linking to other constituents. Both the actual melting point of sucrose and the subsequent transformation, or carmelization, reaction are effected by the presence of water, ammonia, and proteinatious substances. Dark roasts represent a higher degree of sugar carmelization than light roasts. The degree of carmelization is an excellent and high resolution method for classifying roasts.Cellulose: A Long Linear Polymer of Anhydroglucose Units Cellulose is the principle fiber of the cell wall of coffee. It is partially ordered (crystalline) and partially disordered (amorphous). The amorphous regions are highly accessible and react readily, but the crystalline regions with close packing and hydrogen bonding may be completely inaccessible. Native cellulose, or cellulose 1, is converted to polymorphs cellulose III and cellulose IV when exposed to heat. Coffees structure is a well developed matrix enhancing the mass uniformity and aiding in the even propagation of heat during roasting. Cellulose exists in coffee imbedded in lignocellulose (an amorphous matrix of hemicellulose and lignin containing cellulose), making up the matrix cell walls. Hemicellusloses are polysaccharides of branched sugars and uronic acids. Lignin is of special note because it is a highly polymerized aromatic. Severe damage occurs to the cell walls of the matrix at distributed temperatures above 446 degrees F and bean surface temperatures over 536 degrees F The actual temperature values will change due tovarying levels of other constituents. Second crack, associated with darker roasts, is the fracturing of this matrix, possibly associated with the volatilization of lignin and other aromatics. Under controlled roasting conditions, the bean environment temperature should never exceed 536 degrees F. A wider safety margin would be achieved by limiting the maximum environment temperature to 520 degrees F. These temperature limits minimize damage to the cell matrix and enhances cup complexity, roasting yield, and product shelf life.Trigonelline: A Nitrogenous Base Found in CoffeeTrigonelline is 100% soluble in water and therefore will end up in the cup. Trigonelline is probably the most significant constituent contributing to excessive bitterness. At bean temperatures of 445 degrees F, approximately 85% of the trigonelline will be degraded. This bean temperature represents a moderately dark roast. For lighter roasts there will be more trigonelline, hence bitterness, but also less sugar carmelization. Caramelized sugar is less sweet in the cup than noncaramelized sugar, so when properly roasted these two constituents form an interesting compliment to each other. Trigonelline melts in it's pure crystalline form at 424 degrees F Degradation of trigonelline begins at approximately 378 degrees F.. The degradation of trigonelline is one of the key constituent control flags for determining the best reaction ratio.Quinic Acid: Member of the Carboxylic Acids GroupQuinic Acid melts in pure crystalline form at 325 degrees E, well below the temperatures associated with the roasting environment. Quinic Acid is water soluble and imparts a slightly sour (not unfavorably as in fermented beans) and sharp quality, which adds to the character and complexity of the cup.Surprisingly, it adds cleanness to the finish of the cup as well. it is a stable compound at roasting temperatures.Nicotinic Acid: Member of the Carboxylic Acid GroupNicotinic Acid melts in pure crystalline form at 457 degrees F. Naturally occurring Nicotinic Acid is bound to the polysaccharide cellulose structure. Nicotinic Acid is also derived in soluble form during roasting. Higher levels of Nicotinic Acid for any given degree of roast are associated with better cup quality. Since it is I 00% soluble, it will end up in the cup. Nicotinic Acid contributes to favorable acidity and clean finish. It's derivation rate is one of the key constituent control flags for determining the best reaction ratio temperature and chemistry propagation rates. Additionally, the interaction of melted Nicotenic Acid with other constituents contributes significantly to the intensity associated with darker roasts.Environment TemperatureThe temperature of the roasting environment determines the specific types of chemical reactions that occur. There is a window of temperatures that produce favorable reactions for the ideal cup characteristics. Temperature values outside of this window have a negative effect on quintessential cup quality. Even within the window values, different temperatures will change the character of the cup, giving the roaster the latitude to develop a personality or style desired, or to tame the rough signature of certain coffees while still optimizing relative quality. System Energy: At any given environment temperature, the amount of energy (BTU) and the roasting system's transfer efficiency will determine the rate at which the specific chemistrywilloccur. Higher levels of both energy andt ransfer efficiency will cause the reactions to progress more quickly. There is a window of reactionrates that will optimize cup quality. This is called the Best Reaction Ratio, or BRR.Best Reaction Ratio (BRR)The best cup characteristic are produced when the ratio of the degradation of trigonelline to the derivation of Nicotinic Acid remains linear. The control model of this reaction ratio is a time/temperature/energy relationship. The environment temperature (ET) establishes the pyrolysis region for the desired chemical reactions while the energy value (BTU) and system transfer efficiency (STE) determines the rate of reaction propagation and linearity of Nicotinic Acid derivation to degradation of trigonelline. Because green bean density varies dramatically, under any given ET / BTU / STE format, the reaction distribution will vary. it takes longer to obtain comparable uniformity for a higher density bean. Monitoring the bean temperature offers a good method of approximating the reaction distribution during this phase of the roasting. The ideal environmental temperature, ET, for best reaction ratio, BRR, is from -401-424 degrees F, with 405 degrees F as the default value. The BTU required is determined by the systems transfer efficiency, or ability to impart the energy to the charge mass.Maximum Environment Temperature (MET)Establishing the thermal environment protocol for the ideal roast is a balancing act. While it is desirable to maintain the BRR temperature and energy levels until the target reactions are achieved, the BRR temperature is well above the carmelization temperature of sucrose. Because many roasting systems exhibit thermal hysterysis using simple temperature regulating schemes, care must be taken not to allow the coffee mass to exotherm. Additionally, limiting the maximum environment temperature,MET, is also important. As previously mentioned, maintaining structural integrity of the cellulose matrix is of great importance. Lower temperatures will reduce surface evaporation of constituents minimizing the capillary action that draws constituents to the surface where they would be volatilized. Hydraulic action, a function of internal pressure which is directly related to bean temperature, is already at work. By limiting the maximum temperature, losses will be minimized and the essence of coffee retained. Consequently, the MET should not exceed 520 degrees F. This roasting system bases the MET value on the actual final bean, or drop temperature, which correlates to the degree of roast.译文在烘焙过程中发生了很多热与化学反应：去碳酸基，奎宁酸的脱水，细分，异构化，聚合，以及复杂的糖反应(焦糖化)。

高导热环氧复合材料干式电抗器热点温升的仿真研究

高导热环氧复合材料干式电抗器热点温升的仿真研究曲展玉1，钟昱尧1，宋岩泽1，2，谢子豪1，孟雨琦1，谢庆1，2（1.华北电力大学电力工程系，河北保定071003；2.华北电力大学新能源电力系统国家重点实验室，北京102206）摘要：干式电抗器的稳定运行影响新型电力系统的输电可靠性。

干式空心电抗器包封材料整体由浸有环氧树脂的玻璃纤维丝经高温固化而成。

本文采用多物理场耦合有限元方法，考虑干式空心电抗器的包封材料热导率对其热点温升的影响，建立了环氧复合材料的COMSOL微观仿真模型和外电路约束下的干式空心电抗器电-磁、流-热耦合计算模型。

将电磁场下的损耗作为热源计算温度场与流场分布，研究在25℃环境温度下常规/高导热环氧复合材料对干式空心电抗器热点温升的影响规律。

结果表明：高导热环氧树脂对复合材料热导率的提升效果显著；包封材料本体及周围空气温度场区域中热点温升最大值为103.75℃，出现在内部第4层包封材料的上端处；不同热导率的复合材料对降低干式电抗器的热点温升有明显差异，其中干式电抗器在高导热环氧树脂复合材料下的热点温度降低了7.55℃。

关键词：干式空心电抗器；热导率；热点温升；多物理场耦合中图分类号：TM215；TM472 DOI:10.16790/ki.1009-9239.im.2024.04.015Simulation study on hot spot temperature rise of dry reactor with high thermal conductive epoxy composite as encapsulating materialQU Zhanyu1, ZHONG Yuyao1, SONG Yanze1,2, XIE Zihao1, MENG Yuqi1, XIE Qing1,2(1. Department of Electrical Engineering, North China Electric Power University, Baoding 071003, China;2. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University, Beijing 102206, China)Abstract: The stable operation of dry-type reactors affects the transmission reliability of new power system. The encapsulating material of dry-type reactor is made of glass fiber filament impregnated epoxy resin cured at high temperature. In this paper, a multiphysics coupled finite element method was used to consider the influence of thermal conductivity of the encapsulating material for dry-type reactor on its hot spot temperature rise, and a COMSOL microscopic simulation model of epoxy composites and an electro-magnetic and flow-thermal coupling calculation model of dry-type reactor under the constraints of external circuits were established. The temperature field and flow field distribution were calculated by using the loss under electromagnetic field as the heat source, and the influence of conventional/high thermal conductive epoxy composites on the hot spot temperature rise of the dry-type reactor at 25℃ of ambient temperature was studied. The results show that the high thermal conductive epoxy resin has a significant improving effect on the thermal conductivity of composites. The maximum hot spot temperature rise in the temperature field area of the encapsulating material body and the surrounding air is 103.75℃, which appears at the upper end of the fourth layer of encapsulating material. The epoxy resin composite with different thermal conductivity has obvious difference on decreasing the hot spot temperature of dry-type reactor, and the hot spot temperature of the dry-type reactor with high thermal conductive epoxy resin composite is reduced by 7.55℃.Key words: dry hollow reactor; thermal conductivity; hot spot temperature rise; multiphysical field coupling0　引言干式电抗器凭借线性度好、饱和性高、损耗小、运行维护方便等优点已成为在“双碳”战略下构建新型电力系统的重要发展方向[1]。

益口葛葛水提物对抑郁-_焦虑小鼠模型的作用研究

分析检测益口葛葛水提物对抑郁-焦虑小鼠模型的作用研究胡祥旭1，杨书恒1，袁雪梅2，胡钧浩1，宋昀翰3，王华林1*（1.武汉轻工大学生命科学与技术学院，湖北武汉 430023；2.安琪酵母股份有限公司，湖北宜昌 443003；3.湖南味康科技有限公司，湖南长沙 410019）摘　要：目的：研究由葛根制备的槟榔风味的益口葛葛咀嚼块水提物对小鼠抗抑郁以及口腔损伤的影响。

方法：将48只昆明小鼠随机分为空白对照组、槟榔组、葛根组、益口葛葛组4组。

空白组正常饲养，干预组用相应的水提物（10 mg·mL-1）涂抹小鼠口腔内壁，左右各15次，涂抹完后禁饮1 h。

4周后对小鼠进行4周的慢性不可预知温和刺激抑郁模型（Chronic Unpredictable Mild Stimulation，CUMS）造模，期间涂抹不中断，然后用小鼠旷场实验（Open Field Test，OFT）、悬尾实验（Tail Suspension Test，TST）、小鼠强迫游泳实验（Forced Swimming Test，FST）以及糖水偏好实验（Sucrose Preference Test，SPT）评价各组的抗抑郁活性。

处死小鼠，比较各组脏器指数，对口腔黏膜、肝进行病理学染色，提取口腔组织RNA检测口腔纤维化关键基因表达情况。

结果：相比于空白组，仅葛根组体重下降，葛根的加工制品可逆转其体重下降，槟榔组可显著降低悬尾、强迫游泳实验小鼠不动时间（P＜0.001，P＜0.001），各组在自发活动、糖水偏好上无统计学差异。

病理染色上，仅槟榔组的口腔黏膜存在明显的免疫细胞浸润和胶原纤维增生，肝组织无明显差异。

结论：槟榔有较好的改善抑郁趋势，但存在明显的口腔损伤，而益口葛葛缓解抑郁的趋势虽然比槟榔稍弱，但不会损伤口腔健康。

关键词：抗抑郁；葛根；槟榔；益口葛葛；口腔纤维化Study on the Effect of Water Extract of Yikou Gege onDepression-Anxiety Mice ModelHU Xiangxu1, YANG Shuheng1, YUAN Xuemei2, HU Junhao1, SONG Yunhan3, WANG Hualin1*(1.School of Life Science and Technology, Wuhan Polytechnic University, Wuhan 430023, China;2.Angel Yeast Co., Ltd., Yichang 443003, China;3.Hunan Weikang Technology Co., Ltd., Changsha 410019, China)Abstract: Objective: To study the eﬀects of water extract of bequel-ﬂavored Yikou Gege chewblock prepared from Pueraria lobata on anti-depression and oral injury in mice. Method: 48 Kunming mice were randomly divided into four groups: blank control group, betel nut group, Gegen group and Yikou Gege group. Normal feeding blank group, intervention group with the corresponding aqueous extract (10 mg·mL-1) daub mouse oral cavity wall, about 15 times each, daub after the forbidden drink 1 h. Four weeks later, the mice were subjected to 4 weeks of depression induced by chronic unpredictable mild stimulation (CUMS), with continuous application during this period. The antidepressant activity of the mice was evaluated by open field test (OFT), tail suspension test (TST), forced swimming test (FST) and sucrose preference test (SPT). The mice were sacriﬁced, and the organ index of each group was compared. The pathological staining of oral mucosa and liver was performed, and RNA was extracted from oral tissue to detect the expression of key genes in oral ﬁbrosis. Result: Compared with the blank group, only the Pueraria lobata group lost weight, and the processed products of Pueraria lobata could reverse the weight loss. The betel nut group could signiﬁcantly reduce the immobility time of the tail suspension and forced swimming test mice (P＜0.001,作者简介：胡祥旭（2000—），男，湖南郴州人，硕士。

番茄木瓜低糖果酱制备及其理化性质研究

番茄木瓜低糖果酱制备及其理化性质研究林志荣1，刘兰2（1.中华全国供销合作总社管理干部学院，北京100032；2.广东石油化工学院，广东茂名100086）摘要:低糖果酱营养健康，但酱体凝胶性差、易析水。

本文以番茄和木瓜为原料，研制番茄木瓜低糖果酱，以感官评分为标准，通过单因素试验和正交试验优化果酱的工艺配方；借助流变仪考察了温度对果酱流变特性的影响，并检测了果酱的保水性、色差、可溶性固形物含量等理化性质。

结果表明，果酱最佳工艺配方为番茄与木瓜配比6∶4，白砂糖30%，柠檬酸0.15%，复合增稠剂（低甲氧基果胶∶黄原胶=2∶1）0.45%。

研制得到的果酱为屈服-假塑性流体，低温下具有较高的表观黏度和剪切稀化度；果酱风味独特，滋味酸甜可口，稳定性好；可溶性固形物含量为35.20%±0.78%，保水性能达到39.44%±1.05%。

关键词:番茄；木瓜；低糖果酱；稳定性；流变性；理化性质中图分类号：TS255.43文献标志码：A文章编号：1008-1038(2022)05-0005-07DOI：10.19590/ki.1008-1038.2022.05.002Study on the Preparation and Physicochemical Propertiesof Tomato and Papaya Low-sugar JamLIN Zhi-rong 1,LIU Lan 2(1.Management Academy of China Cooperative,Beijing 100032,China;2.Guangdong Universityof Petrochemical Technology,Maoming 100086,China)Abstract:The low-sugar jam is nutritious and healthy,but the gel of the jam is poor and easy to separate water.Alow-sugar flavor jam was prepared from tomato and papaya.According to the sensory evaluation,the formula of jam was optimized by single factor test and orthogonal test.The effect of temperature on the rheological properties of jam was investigated by rheometer.The physical and chemical properties of jam,such as water retention,color difference and solid content,were tested.The results showed that the optimal formula of tomato and papaya jam was the ratio of tomato to papaya 6∶4,sucrose 30%,citric acid 0.15%and compound thickeners 0.45%.The jam was a yield pseudoplastic fluid with high apparent viscosity and shear thinning degree at low temperature.The jam had unique flavor,sour and sweet taste and good stability.The soluble solid content was 35.20%±0.78%,and the water retention performance reached 39.44%±1.05%.Keywords:Tomato;papaya;low-sugar jam;stability;rheological properties;physicochemical properties果蔬加工Process中国果菜China Fruit &Vegetable第42卷,第5期2022年5月收稿日期:2022-01-07基金项目:茂名市科技计划项目（21105125）第一作者简介:林志荣（1979—），女，讲师，博士，主要从事农产品加工与贮藏方面的研究工作番茄含有人体所需的多种微量元素，营养丰富且风味独特。

乳酸胁迫对Pichia_kudriavzevii固态发酵特性的影响

潘婉舒，林晓芳，杨小平，等. 乳酸胁迫对Pichia kudriavzevii 固态发酵特性的影响[J]. 食品工业科技，2024，45（4）：116−122. doi:10.13386/j.issn1002-0306.2023050193PAN Wanshu, LIN Xiaofang, YANG Xiaoping, et al. Effects of Lactic Acid Stress on the Solid-state Fermentation of Pichia kudriavzevii [J]. Science and Technology of Food Industry, 2024, 45(4): 116−122. (in Chinese with English abstract). doi:10.13386/j.issn1002-0306.2023050193· 生物工程 ·乳酸胁迫对Pichia kudriavzevii 固态发酵特性的影响潘婉舒1，林晓芳2, *，杨小平3，徐　洋1，侯　鑫1（1.宜宾学院农林与食品工程学部，四川宜宾 644000；2.四川省春源品悟酒业有限公司，四川成都 611530；3.玉蝉集团有限公司，四川泸州 646603）摘　要：浓香型白酒糟醅富含乳酸，库德毕赤酵母（Pichia kudriavzevii ）为其中优势酵母。

为探究乳酸对浓香型白酒优势酵母固态发酵特性的影响，在不同浓度的乳酸胁迫下，从碳源消耗、生长因子利用、高温耐受性以及主要代谢产物生成等方面，考查P. kudriavzevii （编号：PY1）的生长代谢转变。

结果表明，乳酸胁迫对P.kudriavzevii 菌落与细胞形态无明显影响，对细胞生长有一定抑制，且这种可逆抑制可被氨基酸及维生素削弱，当培养温度超过44 ℃，乳酸对菌株生长的影响逐渐让位于温度。

代谢方面，乳酸可提高葡萄糖、半乳糖、麦芽糖、果糖和蔗糖利用率；增加乙醇和酯类生成量、降低高级醇生成量。

模拟高渗条件对茯茶中“金花菌”生长特性的影响

第39卷第1期陕西科技大学学报 V o l.39N o.1 2021年2月 J o u r n a l o f S h a a n x iU n i v e r s i t y o f S c i e n c e&T e c h n o l o g y F e b.2021* 文章编号:2096-398X(2021)01-0063-07模拟高渗条件对茯茶中金花菌”生长特性的影响杨苗1,张羽欣1,汪梦雯1,李康杰1,胡歆2,夏飞1,秦俊哲1*(1.陕西科技大学食品与生物工程学院,陕西西安 710021;2.国家林业和草原局茯茶工程技术研究中心,陕西咸阳 712000)摘要:茯砖茶发源于泾阳,古法制作具有非泾阳之水而不能制”之说.泾阳地下水中N a+㊁C a2+㊁M g2+浓度高于其他内陆河流域.为探究金花菌”对水中较高离子浓度的适应,及其在茯砖茶生产中稳定生长的机制.从泾阳茯砖茶中分离出若干金花菌”,并选取其中2株代表性菌株进行鉴定;进而探讨不同浓度阳离子和高糖模拟高渗环境对金花菌”生长特性的影响.结果表明:茯砖茶中分离出两株金花菌”F-2和J-2分别与A s p e r g i l l u s i n t e r m e d i u s和肋状散囊菌(A s p e r g i l l u s c o s t i f o r m e)具有高度相似性.2株金花菌”能够在22.5%的N a C l和10.5%的C a C l2和M g C l2培养基上生长,且M g C l2的添加对金花菌”的生长具有明显促进作用. 金花菌”能够耐受70%蔗糖浓度,在高糖㊁高盐模拟的高渗条件下, 金花菌”气生菌丝生长旺盛,产生灰绿色分生孢子头,进行无性生殖. 金花菌”极可能通过选择生殖方式对抗高渗胁迫,其有性生殖产生的子囊果结构更能抵抗不利环境.对于揭示茯砖茶中金花菌”生长机理具有重要作用,为进一步促进发花”效果及提高茯砖茶品质奠定了坚实基础.关键词: 金花菌”;高渗条件;显微结构;生长特性中图分类号:Q939.97 文献标志码:AE f f e c t o f s i m u l a t e dh y p e r t o n i c c o n d i t i o n s o n t h e g r o w t hc h a r a c t e r i s t i c s o f"J i n h u a f u n g u s"i n f u b r i c k t e aY A N G M i a o1,Z H A N G Y u-x i n1,WA N G M e n g-w e n1,L IK a n g-j i e1,HU X i n2,X I AF e i1,Q I NJ u n-z h e1*(1.S c h o o l o fF o o da n dB i o l o g i c a l E n g i n e e r i n g,S h a a n x iU n i v e r s i t y o f S c i e n c e&T e c h n o l o g y,X i'a n,710021,C h i n a;2.F ub r i c kT e aE n g i n e e r i n g T e c h n o l o g y R e s e a r c hC e n t e r,S t a t eF o r e s t r y a n dG r a s s l a n dB u r e a u,X i a n-y a n g712000,C h i n a)A b s t r a c t:F u b r i c k t e a o r i g i n a t e d f r o mJ i n g y a n g,S h a a n x i.T h e r e i sa no l ds a y i n g"I t c a n'tb ep r o d u c e dw i t h o u t t h ew a t e r o f J i n g y a n g",T h e i n v e s t i g a t i o n f o u n d t h a t t h e c o n c e n t r a t i o n s o fN a+,C a2+,a n d M g2+i nJ i n g y a n gg r o u n d w a t e r a r eh i g h e r t h a no t h e r i n l a n dr i v e rb a s i n s.I no r d e r t o r e v e a l t h e a d a p t a t i o nm e c h a n i s mo f"J i n h u a f u n g u s"t oh i g h e r i o n c o n c e n t r a t i o n a n dw h i c hc a n s t a b l y e x i s t i n t h e p r o d u c t i o no f F u b r i c k t e a.I n t h i s s t u d y,s e v e r a l s t r a i n s o f"J i n-*收稿日期:2020-09-09基金项目:国家自然科学基金项目(31801513);陕西省科技厅自然科学基金面上项目(2018J M3003);陕西省创新人才推进计划项目(2018T D-019);陕西省大学生创新创业训练计划项目(S202010708076)作者简介:杨苗(1994-),女,陕西渭南人,在读硕士研究生,研究方向:食品微生物通讯作者:秦俊哲(1958-),男,陕西泾阳人,教授级高级工程师,研究方向:茯砖茶加工工艺开发,q i n j z@s u s t.e d u.c n陕西科技大学学报第39卷h u a f u n g u s"i s o l a t e d f r o mJ i n g y a n g F u b r i c k t e a a n d t w o r e p r e s e n t a t i v e s t r a i n sw e r e s e l e c t e df o r i d e n t i f i c a t i o n.T h e e f f e c t so f d i f f e r e n t c o n c e n t r a t i o n so f c a t i o no nt h eg r o w t ho f"J i nh u af u ng u s",a sw e l l a s g r o w th c h a r a c t e ri s t i c s o f"J i n h u aF u n g u s"i n s i m u l a t e h y p e r o s m o t i c e n v i-r o n m e n tw e r e f u r t h e re x p l o r e d.T h er e s u l t ss h o w e dt h a ts t r a i nF-2a n ds t r a i nJ-2i s o l a t e df r o m F u b r i c kt e a w e r eh igh l y si m i l a rt o A s p e r g i l l u s i n t e r m e d i u s a n d A s p e r g i l l u sc o s t i-f o r m e,2s t r a i n so f"J i n h u a f u ng u s"c o u l d g r o wo nth e m e di u ms u p p l e m e n t e dw i t h22.5%N a C l a n d10.5%C a C l2a n dM g C l2.T h e a d d i t i o no fM g C l2c a no b v i o u s l yp r o m o t e t h e g r o w t ho f"J i n h u af u n g u s",a n d"J i n h u af u n g u s"c o u l dt o l e r a t e70%s u c r o s e,u n d e rh i g h-s u g a ro r h i g h-s a l t h i g h-o s m o t i c c o n d i t i o n s,t h e a u r e u sm y c e l i u m g r o w s v i g o r o u s l y a n d p r o d u c e s g r a y-g r e e n c o n i d i a f o r a s e x u a l r e p r o d u c t i o n."J i n h u a f u n g u s"c o u l d r e s i s t s t r e s s b y c h o o s i n g r e p r o-d u c t i v em e t h o d s,a n d i t sa s c o m y c e t es t r u c t u r ew a sm o r ec o n d u c i v e t or e s i s t i n g e x t e r n a l a d-v e r s i t y.T h i s s t u d y h a s a n i m p o r t a n t r o l e i n r e v e a l i n g t h e g r o w t hm e c h a n i s mo f"J i n h u a f u n-g u s"i nF u b r i c kt e a,a n d l a y sas o l i d f o u n d a t i o nf o r f u r t h e r p r o m o t i n g t h e"f u n g i g r o w i n g"e f f e c t a n d i m p r o v i n g t h e q u a l i t y o f F u b r i c k t e a.K e y w o r d s:J i n h u a f u n g u s;h y p e r o s m o t i c p r e s s u r e;m i c r o s t r u c t u r e;g r o w t hc h a r a c t e r i s t i c s0 引言茯砖茶发源于泾阳,属于六大茶类中的黑茶[1],其主要区别于其他黑茶的特征就是茶砖内部长有金花”, 金花”是由散囊菌属产生的闭囊壳[2].茯砖茶能够消食解腻,深受大众喜爱.古时流传有非泾阳之水不能制茯茶”之说.茯砖茶生产的关键在于其发花”工艺, 金花菌”对于茯砖茶品质形成起着至关重要的作用[3-6]. 金花菌”能够降低原料茶的苦涩味,增加其醇和感[7,8],并且能够产生水溶性色素以及多种香气成分[9-12],以形成茯砖茶独有的风味,并促进其品质的形成.目前研究表明,温度㊁湿度是控制发花”的最主要因素;但是关于水质如何影响金花菌”的生长,进而影响茯砖茶的品质,还尚未有结论.调研证实,泾阳地区地下水以微咸水为主,泾河流域地下水中阳离子浓度最高的为N a+㊁C a2+㊁M g2+,平均浓度高于黄河及长江等内陆河流域及全球河流[13,14],且生产企业多以地下水加工茯砖茶.水中的这些离子对金花菌”生长有何影响,其机制还尚不明确.为探究金花菌”对于高渗培养条件的生长适应,本研究从茯砖茶中分离金花菌”,并采用形态学结合分子生物学技术进行鉴定.选择典型的2株金花菌”对其在蔗糖和N a C l模拟高渗条件的下的生长特性进行研究.本研究对于揭示金花菌”适应较高盐度的生长机制,为进一步明确茯砖茶品质形成的作用机理,提高茯砖茶品质奠定坚实基础.1 材料与方法1.1 实验材料1.1.1 原料及菌种茯砖茶,购自泾阳茯茶镇.1.1.2 主要试剂和培养基蔗糖㊁葡萄糖㊁氯化钠㊁氯化镁㊁氯化钙,以上试剂均为分析纯,购于天津市红岩化学试剂厂;琼脂粉㊁蛋白胨为生化试剂,产自北京奥博星生物技术有限责任公司;真菌基因组提取试剂盒(天根生化科技有限公司).P D A培养基:马铃薯200g煮沸过滤去渣,葡萄糖2g,琼脂20g,蒸馏水1000m L,自然p H.C Z G培养基:蔗糖20g,氯化钠23g,磷酸氢二钾l g,硝酸氨3g,硫酸镁0.5g,琼脂20g.1.1.3 主要仪器立式压力蒸汽灭菌器(L S-C50L,江阴滨江医疗设备厂);台式扫描电镜(P h e n o m e n o nP r o,复纳科学仪器有限公司);凝胶成像仪(F R-1000,上海复日科技有限公司);P C R仪(T100,B i o-R a d);离心机(T D L-80-2B,上海安亭科学仪器厂);霉菌培养箱(M J X-150-Ⅱ,北京科伟永兴仪器有限公司).1.2 实验方法1.2.1 金花菌”的鉴定(1)平板形态观察将分离出的金花菌”单点接种于不同培养基平板,在28℃下培养4d,对其平板单菌落形态进行观察.(2)电镜下金花菌”形态观察制样方法:样品台上粘贴导电胶,挑取金花菌”至导电胶上,室温下放置24h,使其干燥后进㊃46㊃第1期杨苗等:模拟高渗条件对茯茶中金花菌”生长特性的影响行观察.(3)转录组间隔区(I n t e r n a lT r a n s c r i b e dS p a c-e r,I T S)序列分析无菌条件下刮取单菌落菌丝,加入灭菌后的石英砂进行研磨,使用天根试剂盒提取D N A.随后使用通用引物I T S1(5'-C T T G G T C A T T T A G A G-G A A G T A A-3')和I T S4(5'-T C C T C C G C T T A T T-G A T A T G C-3')进行I T S序列扩增[15].反应体系包括上游引物1μL,下游引物1μL,2×T a q预混合M i x12.5μL,D N A模板5μL以及5.5μL超纯水.扩增条件为:95℃预变性5m i n,随后在94℃变性30s,52℃退火30s,72℃延伸45s之后,进行32个循环的扩增.循环结束后,72℃延伸7 m i n[16],P C R产物经1.0%琼脂糖凝胶电泳确认片段大小后,交由生工生物工程股份有限公司进行测序分析.测序结果提交N C B I数据库进行比对,并采用M E G A5.0软件绘制系统发育树,选用N e i g h b o r-J o i n i n g绘图算法,重复迭代1000次[17].1.2.2 金花菌”高渗条件下特性研究(1)蔗糖含量对金花菌”生长的影响以C Z G培养基为基础,分别添加20%㊁70%蔗糖,观察蔗糖产生的高渗条件对金花菌”生长的影响.(2)盐离子对金花菌”生长的影响以40%蔗糖蛋白胨培养基作为基础,添加0.5%~22.5%的N a C l,将分离出的金花菌”接种于各盐浓度平板上,同时将从茯砖茶分离出的杂菌黑曲霉及青霉接于各盐浓度平板,观察其生长情况;以40%蔗糖蛋白胨培养基作为基础,对比添加C a C l2和M g C l2对金花菌”生长的影响.(3)高渗条件对金花菌”的生殖方式的影响挑取纯化后的金花菌”菌株,将其单点接于不同培养基平板上,通过插片培养,2d后开始在显微镜下观察其形态并拍照.1.3 统计分析每个试验重复3次,方差分析采用L S D法进行计算,结果以M e a n s±S D表示.2 结果与讨论2.1 金花菌”平板菌落形态从茯砖茶中共分离出21株金花菌,选取2株平板形态差异较大的金花菌”F-2和J-2单点接种于P D A培养基上,28℃培养4d.如图1(a)所示,菌株F-2菌落中心呈深褐色,中心有褐色液滴产生,并且色素渗透至培养基中,菌株外圈菌丝呈白色;菌株J-2菌落呈鹅黄色,菌落外圈白色菌丝生长,该菌株不产生色素(如图1(b)所示).(a)菌株F-2 (b)菌株J-2图1 金花菌”在P D A平板培养4d形态2.2 金花菌”的显微形态特征金花菌”既能够进行有性生殖也可进行无性生殖.在金花菌”有性生殖过程产生子囊果(如图2(a)所示),子囊果中包含着子囊(如图2(b)所示),子囊中内含8个子囊孢子(如图2(c)所示).子囊果外层有着一层外壳包被,在释放孢子时,外壳破裂,释放出其中的子囊,子囊在子囊果中有相应的座位”,排列紧凑,且不形成挤压,子囊在发育初始阶段外面包被有一层薄膜,待发育成熟后,逐渐撑破外层薄膜,孢子被释放出来,孢子的外层呈坚硬状.(a)包被完整的子囊果 (b)破裂的子囊果(c)子囊 (d)子囊孢子图2 金花菌”有性生殖的显微形态金花菌”无性生殖产生分生孢子,分生孢子头上分生孢子呈串状排列,分生孢子为中空椭圆形,粗糙具小刺.分生孢子直接裸露在外,外层无包被(如图3所示).菌株F-2与J-2的子囊孢子均呈现凸镜状,凸面具有小疣或褶皱,并且具有赤道(如图4(b)㊁(d)所示).但F-2与J-2的子囊孢子形态不完全相同,㊃56㊃陕西科技大学学报第39卷F-2的子囊孢子脊较短,不规则,且赤道部分较宽,根据‘中国真菌志“及曲霉分类学[18],认为F-2与A s p e r g i l l u s i n t e r m e d i u s孢子形态极为相似,F-2可能为A.i n t e r m e d i u s.J-2的赤道沟较深,且凸面上形成网结的肋状凸起,这与肋状散囊菌(A.c o s t-i f o r m e)的形态特征相似,且其在P D A㊁40%蔗糖蛋白胨㊁40%蔗糖麦芽汁㊁20%蔗糖C Z G及70%蔗糖C Z G等多种培养基上培养均未见到有色素产生,结合其培养特征[19],认为J-2与肋状散囊菌(A.c o s t i f o r m e)具有高度一致性.(a)分生孢子头 (b)串状排列(c)分生孢子图3 金花菌”无性生殖的显微形态(a)F-2子囊果(1450×)(b)F-2子囊孢子(7700×)(c)J-2子囊果(1500×)(d)J-2子囊孢子(8900×)图4 金花菌”子囊果和子囊孢子的显微形态2.3 I T S序列分析金花菌”F-2和J-2与A s p e r g i l l u s的多个菌株具非常高的相似度.通过构建系统发育树(如图5所示),发现F-2㊁J-2与P e n i c i l l i u m(青霉属),T a l a r o-m y c e s(篮状菌属)等分别属于两个簇,与E u r o t i u m m e d i u m,A.i n t e r m e d i u s,A.c o s t i f o r m i s等9个菌株属于同一分支中,具有非常高的同源性.图5 F-2及J-2的系统发育分析金花菌”是以冠突散囊菌为主的散囊菌属真菌,散囊菌属真菌具有高度同源性[20,21],根据其系统发育分析,菌株F-2和J-2与A.i n t e r m e d i u s等9株菌高度同源性.由于I T S的分辨率达不到种水平以下的分类[21],经过I T S序列比对只能将两株金花菌”鉴定到属.系统发育树中E.m e d i u m与A.i n t e r m e d i u s属于同一分支,这是由于以前对于该属的命名分为有性型和无性型命名,国际青霉菌和曲霉菌委员会(I C P A)为了避免命名混淆,将所有的E u r o t i u m分类群转移到A s p e r g i l l u s[18],这种做法也被广为接受,很多作者倾向于使用A s-p e r g i l l u s[22].结合菌株F-2和J-2的形态特征,F-2极可能为A.i n t e r m e d i u s,J-2与肋状散囊菌(A.c o s t i-f o r m e)的形态特征吻合,具有极高相似度.2.4 蔗糖模拟高渗条件对金花菌”生长的影响两株金花菌”在20%蔗糖C Z G培养基上,气生菌丝生长受限,产生较多子囊果,菌丝包裹子囊果在培养基表面形成米褐色小斑状.随着培养时间延长,菌落中间的斑点逐渐变大,颜色加深,未见有液体渗出.在此培养基上只进行有性生殖,未见有分生孢子出现.F-2在培养初期菌落颜色呈现浅黄色,当培养至6d时,产生近橄榄褐色色素,渗透到基质中(如图6(a)㊁(b)所示);J-2始终未产生色素,反面为黄色.采用70%蔗糖C Z G培养基模拟高渗条件,研究金花菌”的生长适应特性.两株金花菌”在70%蔗糖C Z G培养基上较20%蔗糖C Z G培养基㊃66㊃第1期杨苗等:模拟高渗条件对茯茶中金花菌”生长特性的影响上约晚24h萌发.生长初期,无色气生菌丝生长,产生灰绿色分生孢子头,随后,产生黄色闭囊壳,菌落呈现黄色,菌落边缘仍有灰绿色分生孢子头.在70%蔗糖C Z G平板上存在有性生殖和无性生殖两种生殖方式.菌株F-2在20%蔗糖C Z G平板上产生色素,在70%蔗糖C Z G平板上不产生色素;菌株J-2在70%蔗糖C Z G也较20%蔗糖C Z G平板上颜色更浅(如图6(c)㊁(d)所示).(a)20%蔗糖C Z G菌落形态(b)70%蔗糖C Z G 菌落形态(c)20%蔗糖C Z G菌落形态(d)70%蔗糖C Z G菌落形态图6 金花菌”在不同蔗糖含量C Z G培养基平板培养7d菌落形态金花菌”在添加高浓度蔗糖的C Z G平板上依然能够生长,而且长势旺盛,表明其能够耐受高糖的环境.有研究者从蔗糖厂的环境及生产的蔗糖成品中均分离出谢瓦散囊菌(A.c h e v a l i e r i),该种真菌能够耐受高糖条件,成为蔗糖生产过程中的一种主要污染菌[23],因此金花菌”在添加70%蔗糖的培养基中仍然能够生长很好. 金花菌”在大多数情况下进行有性生殖,但在高糖诱导下产生无性型,主要是由于有性生殖是对营养限制及环境刺激作出的反应,而在营养丰富的时候会进行无性生殖[24].2.5 盐离子对金花菌”生长的影响金花菌”在40%蔗糖蛋白胨培养基上培养4天菌落直径约为3.8c m.在添加了0.5%~22.5%的N a C l的40%蔗糖蛋白胨培养基上, 金花菌”均能够生长. 金花菌”在N a C l浓度较低的情况下形成较多黄色闭囊壳,菌落中心呈黄色,外部边缘为白色绒毛状菌丝,但是随着N a C l浓度的增大,在萌发后先产生大量茂盛的白色菌丝体,其菌落呈灰绿色,随着菌的不断生长,开始逐渐形成黄色闭囊壳.在添加0.5%~15.5%的N a C l培养基中培养4天,菌落直径如表1所示.两株金花菌”均在添加4.5%N a C l的培养基上菌落直径最大,生长最好,J-2的菌落直径为4.53 c m,而F-2的菌落直径达到4.82c m.随着培养基中N a C l含量的升高, 金花菌”生长受到抑制,其菌落直径也随之减小.虽然高浓度N a C l抑制金花菌”萌发,但2株金花菌”在高糖高盐培养基上仍能很好生长(如图7所示).与金花菌”对比,黑曲霉在添加0.5%~15.5%N a C l的平板上可以生长,但当N a C l添加量达到11.5%时,其生长受到抑制,萌发时间延长.青霉在含N a C l平板中生长受限,当N a C l含量达到8.5%时,菌株未萌发.(a)16.5%N a C l F-2形态 (b)16.5%N a C l J-2形态(c)18.5%N a C l F-2形态(d)18.5%N a C l J-2形态(e)20.5%N a C l F-2形态(f)20.5%N a C l J-2形态(g)22.5%N a C l F-2形态(h)22.5%N a C l J-2形态图7 金花菌”在含有不同浓度N a C l的40%蔗糖蛋白胨培养基培养20d的生长形态金花菌”能够耐受一定浓度的C a C l2和M g C l2,M g2+一定程度上可促进金花菌”生长,并且其他研究证实,镁离子能够促进真菌菌体生长[25].通过对泾阳地表水和地下水中化学成分的分析,N a+和M g2+为主控阳离子.适量N a C l会促㊃76㊃陕西科技大学学报第39卷进金花菌”生长,随着N a C l 含量的增加,会推迟金花菌”萌发时间.表1 不同N a C l 浓度40%蔗糖蛋白胨培养基上F -2和J -2菌落直径盐浓度/%0.51.52.53.54.55.56.57.5F -2菌落直径/c m 3.87±0.03c 3.87±0.03c 3.42±0.14e 2.98±0.10g4.82±0.07a 4.16±0.11b 4.16±0.03b 3.60±0.03d J -2菌落直径/c m3.28±0.03e f 3.53±0.03d 3.27±0.07e f 2.64±0.03i4.53±0.03a 4.35±0.03b 3.95±0.03c 3.35±0.03e黑曲霉菌落直径/c m9.00±0.00a 9.00±0.00a 6.76±0.25b 4.50±0.07c 3.41±0.03e 4.28±0.03d 2.70±0.08f 2.26±0.03g 青霉菌落直径(c m )1.32±0.07a 1.31±0.06a 0.50±0.03d 0.57±0.02d 0.95±0.10b 0.68±0.05c 0.27±0.05e 0.22±0.00e 盐浓度/%8.59.510.511.512.513.514.515.5F -2菌落直径/c m 3.46±0.07e3.14±0.07f3.63±0.03d2.75±0.03h2.49±0.03i2.10±0.03j1.71±0.07l1.84±0.07kJ -2菌落直径/c m3.20±0.03f g 2.83±0.08h 3.33±0.04e 3.14±0.07g 2.49±0.03j2.23±0.03k 1.18±0.03l 0.47±0.03m 黑曲霉菌落直径/c m1.74±0.03h 1.41±0.08i 1.39±0.02i 1.38±0.10i 1.09±0.03j 0.74±0.03k 0.52±0.04l 0.43±0.03l 青霉菌落直径/c m////////注:表中方差分析采用L S D 法进行计算,不同字母表示该数据在P <0.05水平上差异具有显著性;/表示未生长将茯砖茶中分离出的黑曲霉㊁青霉同金花菌”同时接于不同浓度N a C l 含量的平板上,发现当N a C l 含量达到8.5%时,青霉不能生长,而当N a C l浓度达到15.5%时,黑曲霉生长已经受到极大抑制,当N a C l 含量增至22.5%时, 金花菌”仍然能够生长.一方面高浓度的N a C l 能够抑制其他杂菌生长,另一方面金花菌”能够耐受高浓度N a C l ,因此水中高浓度N a C l 有利于茯砖茶发花”而不受到杂菌污染.2.6 高渗条件对金花菌”的生殖方式的影响金花菌”在高渗培养基上,气生菌丝生长茂盛,随后形成球型顶囊(如图8(a )所示),在顶囊上长出单层小梗(如图8(b)所示),逐渐发育,在分生孢子梗上产生分生孢子(如图8(c )㊁(d )所示).金花菌”在70%蔗糖C Z G 培养基上及在高盐浓度的40%蔗糖蛋白胨培养基培养的过程中,开始先进行无性生殖,随着培养时间的延长,逐渐进行有性生殖. (a )球型顶囊 (b)顶囊长出单层小梗(c )形成分生孢子梗 (d)分生孢子成熟图8 金花菌”无性生殖发育过程金花菌”在处于胁迫环境时可以通过选择生殖方式以适应环境. 金花菌”常规培养条件下均进行有性生殖.在高盐高糖诱导下, 金花菌”改变生殖方式,进行无性生殖,产生分生孢子,无性生殖是一种较低级的生殖方式.通过观察发现随着N a C l含量的升高, 金花菌”产生灰绿色分生孢子头进行无性生殖.有研究发现在平板中添加3M 的N a C l 会使金花菌”只进行无性生殖[24],在本研究中,当N a C l 添加量为18.5%时,仍然存在有性和无性两种生殖方式,可能是由于选用的培养基不同,营养状态不一致导致.在极端环境时,首先菌丝生长进行营养增殖,选择较为简单的无性繁殖方式产生分生孢子,随后再进行有性生殖,产生子囊孢子. 金花菌”主要进行有性生殖,使其能够耐受逆境.在胁迫环境下, 金花菌”子囊果㊁子囊对子囊孢子形成重重保护,使其能够耐受较高的渗透压,在条件适宜时又会重新萌发. 金花菌”的子囊孢子结构较分生孢子更稳定,分生孢子在外力作用下发生变形,甚至破裂,而子囊孢子几乎无变化. 金花菌”不仅存在结构优势能够适应逆境,同时存在一些抗逆基因,能够有利于其对抗胁迫,在一些研究中发现谢瓦散囊菌(A .c h e v a l i e r )中分离出G D H 基因能够有利于水稻耐干旱胁迫[26].金花菌”在茯砖茶的生产过程中是优势菌,具有极强降解能力,但在其他行业中,如制糖工业,烟业中, 金花菌”却是一种污染菌,通过本研究对金花菌”对各种离子的耐受以及耐高渗特性的揭示,更有利于金花菌”在茯砖茶生产中的应用及在其他行业中的控制,为工业中有效利用和控制金花菌”奠定基础.3 结论茯砖茶中分离出两株金花菌”F -2和J -2分别㊃86㊃第1期杨苗等:模拟高渗条件对茯茶中金花菌”生长特性的影响与A s p e r g i l l u s i n t e r m e d i u s和肋状散囊菌(A s-p e r g i l l u s c o s t i f o r m e)具有高度相似性.2株金花菌”能够在22.5%的N a C l和10.5%的C a C l2和M g C l2培养基上能够生长,且M g C l2的添加对金花菌”的生长具有明显促进作用. 金花菌”能够耐受70%蔗糖浓度,在高糖㊁高盐模拟的高渗条件下, 金花菌”气生菌丝生长旺盛,产生灰绿色分生孢子头,进行无性生殖. 金花菌”极可能通过选择生殖方式对抗高渗胁迫,其有性生殖产生的子囊果结构更能抵抗不利环境.参考文献[1]王增盛,施兆鹏,刘仲华,等.论茯砖茶品质风味形成机理[J].茶叶科学,1991,11(S1):49-55.[2]齐祖同,孙曾美.茯砖茶中优势菌种的鉴定[J].菌物学报,1990,9(3):176-179.[3]陈云兰.茯砖茶金花菌”的分类鉴定及其对茯砖茶品质的影响[D].南京:南京农业大学,2004.[4]胡治远,刘素纯,赵运林,等.茯砖茶生产过程中微生物动态变化及优势菌鉴定[J].食品科学,2012,33(19):244-248.[5]刘石泉,胡治远,赵运林.用D G G E法初步解析茯砖茶渥堆发酵过程中真菌群落的结构[J].湖南农业大学学报(自然科学版),2014,40(5):494-500.[6]赵仁亮,胥伟,吴丹,等.基于I l l u m i n a M i S e q技术分析不同地域加工的茯砖茶中微生物群落多样性[J].生态学杂志,2017,36(7):1865-1876.[7]黄群,陈林杰,李彦坡,等.冠突散囊菌黑茶发酵液对消化酶活性影响的研究[J].微生物学通报,2007,34(5):917-920.[8]宛晓春.茶叶生物化学[M].3版.北京:中国农业出版社,2008:91-95.[9]刘作易,秦京. 金花”菌与茯砖茶品质[J].山地农业生物学报,1991,13(1):79-82.[10]赵仁亮,吴丹,姜依何,等.不同产地黑毛茶加工的茯砖茶香气成分和品质分析[J].湖南农业大学学报(自科版),2017,43(5):551-555.[11]王华夫,李名君,刘仲华,等.茯砖茶在发花过程中的香气变化[J].茶叶科学,1991,11(S1):81-86.[12]沈程文,邓岳朝,周跃斌,等.湖南茯砖茶品质特征及其香气组分研究[J].茶叶科学,2017,37(1):38-48. 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[25]韦啟球,刘凡,张世倡,等.多种金属离子对一株双齿相手蟹肠道共生真菌生长代谢影响的研究[J].广东微量元素科学,2012,19(3):16-21.[26]吴湘霞.异源表达谢瓦散囊菌谷氨酸脱氢酶基因E c G D H对水稻抗旱性的影响[D].长沙:湖南大学,2018.【责任编辑:陈佳】㊃96㊃。

评价左卡尼汀配合蔗糖铁注射液治疗维持性血液透析期间并发肾性贫血的效果

论著DOI：10.16662/ki.1674-0742.2023.03.015评价左卡尼汀配合蔗糖铁注射液治疗维持性血液透析期间并发肾性贫血的效果张静静，徐亚光，王天舒聊城市第二人民医院（山东第一医科大学附属聊城二院）肾内科，山东聊城252600［摘要］目的研究维持性血液透析并发肾性贫血开展左卡尼汀配合蔗糖铁注射液治疗的临床效果。

方法方便选取2020年4月—2021年6月间聊城市第二人民医院收治入院的68例维持性血液透析的肾性贫血患者为研究对象，以随机数字表法分为常规组（n=34）和研讨组（n=34）。

常规组开展蔗糖铁注射液治疗，研讨组开展蔗糖铁注射液+左卡尼汀治疗，对比两组临床疗效、贫血指标（血红蛋白、血细胞比容、红细胞、前白蛋白）、不良反应（血管刺激、皮疹、胃肠道反应）及氧化应激指标。

结果研讨组总治疗有效率为94.12%，高于常规组，差异有统计学意义（χ2=4.220，P=0.039）。

研讨组患者治疗后血红蛋白（118.48±14.27）g/L、血细胞比容（36.24±3.49）%、前白蛋白（0.32±0.07）g/L及红细胞（2.43±0.46）×1012/L指标均较常规组更高，差异有统计学意义（t=4.637、5.150、5.692、4.078，P<0.05）。

两组不良反应发生情况比较，差异无统计学意义（P>0.05）。

研究组氧化应激指标改善效果优于常规组，差异有统计学意义（P<0.05）。

结论左卡尼汀配合蔗糖铁注射液治疗维持性血液透析并发肾性贫血可提高总体治疗效果，在改善患者贫血症状方面的效果显著，且不会增加药物不良反应。

［关键词］维持性血液透析；肾性贫血；左卡尼汀；蔗糖铁注射液；疗效［中图分类号］R692 ［文献标识码］A ［文章编号］1674-0742（2023）01(c)-0015-05Evaluation of the Effect of Levocarnitine Combined with Iron Sucrose In⁃jection in the Treatment of Renal Anemia during Maintenance Hemodialy⁃sisZHANG Jingjing, XU Yaguang, WANG TianshuDepartment of Nephrology, Liaocheng Second People's Hospital (the Second Affiliated Liaocheng Hospital of Shan⁃dong First Medical University), Liaocheng, Shandong Province, 252600 China[Abstract] Objective To study the clinical efficacy of levocarnitine combined with sucrose iron injection in the treat⁃ment of renal anemia complicated by maintenance hemodialysis. Methods 68 patients with renal anemia admitted to Liaocheng Second People's Hospital from April 2020 to June 2021 were conveniently selected as the study subjects. They were randomly divided into a conventional group (n=34) and a study group (n=34) using a random number table method. The conventional group received treatment with sucrose iron injection, while the study group received treat⁃ment with sucrose iron injection and levocarnitine. The clinical efficacy, anemia indicators (hemoglobin, hematocrit, red blood cells, prealbumin), adverse reactions (vascular stimulation, rash, gastrointestinal reaction), and oxidative stress indicators were compared between the two groups. Results The total effective rate of treatment in the study group was 94.12%, higher than that in the conventional group, and the difference was statistically significan (χ2= 4.220, P=0.039). After treatment, the patients in the study group had hemoglobin (118.48±14.27) g/L, hematocrit (36.24±3.49)%, prealbumin (0.32±0.07) g/L, and red blood cells (2.43±0.46) ×1012/L indicators were higher than those of the conventional group, and the difference was statistically significan (t=4.637, 5.150, 5.692, 4.078, P<0.05). There was no statistically significant difference in the incidence of adverse reactions between the two groups (P>0.05). The[作者简介] 张静静（1985-），女，硕士，主治医师，主要从事慢性肾脏病一体化治疗相关工作。

糖分含量对番茄叶片Pst DC3000抗性的影响及其机理

番茄(Solanum lycopersicum )是世界上重要的蔬菜作物之一。据联合国粮农组织统计,2018年世界番茄总产量高达1-82亿w其中我国番茄总产量为0.6^i,占比34% ( FAO,2018 )o番茄在实际生产中病害发生严重，其中Pseudoffas syrifgae pv. tomato DC3000 ( Pst DC3000)引起的细菌性叶斑病危害番茄叶片、叶柄、茎、花和果实，对番茄质量和产量均会产生严重不利影响［1-3］。该病害一般会导致番茄减产10% 30%，严重时达到50%以上⑷。Pst DC3000可在田间存活较长时间,并通过整枝、打杈、采收等相关农业活动进行传播或再侵染,病菌在田间进行多次重复再侵染，加重危害，防治较为困难［5］( 田间长期使用杀菌剂不仅导致病菌产生抗药性, 而且会造成环境污染和食品安全等问题。因此, 亟需深入了解番茄对Pst DC3000的防御机制，以期培育出抗细菌性叶斑病的番茄新品种。
-1002 -
浙江农业学报第33卷第6期
salicylic acid ( SA) and jasmonic acid (JA), cell death incidence and H2O2 accumulation. It was found that, as compared with the mornina-sampled leaves, the evenina-sampled leaves showed higher resistance to Pst DC3000 as revealed by less incidence of disease lesion and cell death, and lower bacterial density i leaves (0"0. 01 ) . /urthermoro, evenina-sampled leaves had higher starch content (0 -48 h) , glucose content (0 h and 24 h), and fruc tose conint (24 h and 48 h). However, there was no significant diCerence in sucrose conint between two kinds of leaves. In addition, the measurement of three kinds of invertase activities showed that evenina-sampUd leaves had lower cell wall invertase ( CWIN) activity at 0 h and 48 h Vter inoculation, but significantly ( 0"0. 05 ) higher cyto plasmic invertase ( CIN) activities at 24 h and 48 h Vter inoculation than mornina-sampled leaves. Notably, there was no significant diCerence in vacuolar invertase ( VIN) activity between two kinds of leaves, FinaVy, as compared with the mornina-sampled leaves, evenina-sampled leaves showed significantly ( 0"0. 05 ) higher content of free SA and JA, and simulineousld less H2 O2 accumulation at 48 h after inoculation. In conclusion, as compared with the morning-sampled leaves, evenina-sampled leaves showed higher starch and hexose content, CIN activity, but lower CWIN activity- These deferences in sugar metabolism may contribui to higher SA and JA conint and less H2 O2 aocumulation and cell death in evenina-sampled leaves, and uldmaVd enhance its resistance to Pst DC3000. Key words: tomato ； bacterial lea- spot ； cell wall invertase ； cytoplasmic invertase ； sugar content

2002现代药品与食品真空冷冻干燥过程中传热传质问题的

国家自然科学基金申请书申报日期： 2002年3月10日国家自然科学基金委员会2. 第一人必须是申请者，信息从前面自动读入。

第 3 页共18 页经费预算(单位:万元)报告正文(一)立项依据与研究内容（4000-8000字）1. 项目的立项依据（附主要的参考文献目录）现代药品大多是热敏性药品，即对温度(主要是高温)比较敏感的药品，如脂质体（liposome）、干扰素(interferon)、组织型纤维蛋白溶酶原激活剂(tissue type plasminogen activator)、白细胞介素(interleukin)、生长激素(human growth hormone)等，还有我国的中草药。

在生产热敏性药品时，为防止由于温度过高而使药品变性，影响产品的质量，目前广泛应用的技术是真空冷冻干燥技术(freeze-drying，lyophilization)。

冷冻干燥技术是将含水物质在低温下冻结，然后在真空条件下通过对冻干物料加热使冰升华，再除去物料中部分吸附水，得到干制品。

用这种方法制造的药品的特征是：结构稳定，生物活性基本不变；药物中的易挥发性成份和受热易变性成份损失很少；呈多孔状，药效好；排除了95-99%的水分，能在室温下长期保存。

[1，2] 同样，冷冻干燥的食品也具有明显的优点：可保持新鲜食品的色、香、味，避免一般干燥方法易产生的营养成分损失和表面硬化现象；提高其复水性和速溶性；食用简单方便；脱水彻底、重量轻、且能在室温下长期保存等。

冷冻干燥被喻为21世纪的食品加工技术，目前国际市场上冻干食品的价格是速冻食品的7-8倍，是热风干燥食品的4-6倍，经济效益十分可观。

[3，4]然而冷冻干燥也有其缺点和难点：冷冻干燥过程耗时长、耗能多；冷冻干燥过程对冻干药品和食品的质量有着决定性的影响。

冷冻干燥过程包括预冷、一次干燥、二次干燥和储存阶段等，都是相当复杂传热传质过程；而且这些过程与药品、食品、赋形剂、低温保护剂的热物性有密切的关系。

糖不甜的特例

糖不甜的特例引言糖是我们日常生活中常见的食品之一，它通常被用作甜味剂，为各种食品和饮料增添美味。

然而，有时我们会遇到一些糖并不甜的特例，这些特例可能是由于个体差异、糖的种类、糖的处理方式等因素所致。

本文将详细探讨糖不甜的特例，并解释可能的原因。

个体差异每个人的味觉都有所不同，这导致了对糖的感知也会有差异。

有些人可能对甜味不敏感，即使糖的浓度很高，他们也无法感受到明显的甜味。

这可能是由于遗传因素、味觉感受器的敏感度差异以及个体偏好的不同所致。

糖的种类不同种类的糖具有不同的甜味特点。

常见的糖类包括蔗糖、葡萄糖、果糖等。

其中，蔗糖是最常用的糖之一，它具有明显的甜味。

然而，其他一些糖类可能并不那么甜，甚至有些味道苦涩或没有明显的甜味。

例如，乳糖是牛奶中的主要糖类，但它的甜味相对较弱。

因此，当我们使用不同种类的糖时，可能会遇到糖不甜的特例。

糖的处理方式糖的处理方式也会影响其甜味的感知。

在烹饪过程中，糖可能会经历加热、溶解、结晶等过程，这些过程可能会改变糖的结构和性质。

举个例子，当糖被加热过度时，它可能会发生焦糖化反应，产生苦味的化合物。

这就解释了为什么有时我们在烘焙过程中使用的糖会呈现出苦涩的味道，而不是甜味。

此外，糖的溶解度也影响其甜味的感知。

一些糖可能在水中溶解得更好，从而更容易被味觉感受器察觉到甜味。

而另一些糖可能溶解度较低，导致其甜味不那么明显。

糖的纯度糖的纯度也是影响其甜味的重要因素之一。

纯度高的糖通常会呈现出更明显的甜味。

然而，由于生产和加工过程中的不同因素，一些糖可能会受到杂质的影响，从而降低其纯度。

这可能导致糖的甜味不如预期，甚至有时会出现异味。

存储和保质期糖的存储和保质期也会影响其甜味的感知。

长时间存放的糖可能会吸湿，导致结晶或黏结，这可能会影响其甜味。

此外，糖在暴露在空气中时可能会吸收异味，从而影响其原本的甜味。

结论糖不甜的特例可能是由于个体差异、糖的种类、糖的处理方式、糖的纯度以及存储和保质期等多种因素所致。

夏枯草花粉离体萌发观察

夏枯草花粉离体萌发观察[通信作者] *郭巧生，Tel：（025）84395980，Email：gqs@夏枯草Prunella vulgaris L.为多年生草本，轮伞花序集成穗状，花萼二唇形；花冠紫色，上唇顶端微凹，下唇中间裂片边缘有细条裂。

花期5～6月。

夏枯草干燥果穗入药，苦、辛、寒，入肝、胆经。

清火明目，治目赤肿痛、头痛；清肝火、降血压，治高血压病、高血脂和高血糖；散结消肿，治瘰疬、瘿瘤、乳痈肿痛。

花粉是有性繁殖植物重要的遗传物质载体，其活力的有无直接影响种子结实与否。

花粉萌发是一个复杂的过程，涉及到体内许多生理生化反应[1]。

研究花粉的离体萌发特性，对于雄配子体的生物学研究和杂交育种、良种繁育、花粉培养等都具有重要的意义。

有资料显示，人工辅助授粉或杂交授粉是常规育种研究中培育新品种的重要途径，而花粉生活力检测是人工授粉的重要环节，因此，开展夏枯草花粉生活力的研究，可以为杂交育种提供有力的理论基础。

花粉生活力的测定方法常用有：花粉萌发、核及原生质染色、荧光染色法及其他染色法[23]。

其中花粉萌发法更接近自然实际情况，而且这种方法还为以克服不亲和性为目的的人工受精和通过花粉进行基因转移等新技术研究奠定基础。

目前没有关于夏枯草花粉离体培养的相关报道，但近年来，国内外不少学者在马铃薯[4]、茶树[5]、陆地棉[6]、乌头[7]等植物花粉活性测定方面进行了研究，认为离体萌发法是测定花粉生活力状况的最简单、可靠的有力手段。

同时还发现培养基种类、不同浓度的蔗糖，PEG，H3BO4，Ca（NO3）2，pH梯度以及培养温度、培养时间、花粉采集时间对花粉萌发有很大的影响[813]，且不同植物对萌发的要求不同，可见有关花粉离体萌发的研究已经成熟。

本实验旨在研究夏枯草花粉离体培养的最佳条件。

为夏枯草人工授粉及更进一步的研究提供基础资料和技术参考，并为其栽培生产和育种实践提供依据。

1 材料与方法1.1 夏枯草试验所用夏枯草由南京农业大学中药材研究所提供，经郭巧生教授鉴定为唇形科植物夏枯草P. vulgaris，栽种于南京农业大学。

响应面法优化复合型红酸汤乳化工艺

响应面法优化复合型红酸汤乳化工艺张东亚;徐俐【摘要】为了解决复合型红酸汤"油酸分离"导致风味、色泽不佳等问题,以吸光度及离心后出油量作为评价复合型红酸汤乳化液稳定性的指标,通过单因素试验筛选出乳化剂的最佳添加量及乳化温度、乳化时间,利用响应面法对影响复合型红酸汤的乳化工艺的因素进行优化.结果表明,最佳乳化条件为:蔗糖酯添加量0.21%,单甘酯的添加量为0.20%,乳化温度为64.73℃,乳化时间为3.09 min,在此工艺条件下,复合型红酸汤吸光度为0.434,稳定性好,不易发生油水分离现象,感官品质好.%The oil-water separation affected the flavor and color of mixed-Red Sour Soup. In order to solve this problem, we investigated the effect of sucrose ester content, mono-glycerides content, emulsifying temperature, emulsifying time on the absorbance value of emulsion of mixed-Red Sour Soup and the amount of separated oil after centrifuge using single factor experiment and response surface methodology. Results shows that the absorbance value of emulsion of mixed-Red Sour Soup under the optimized conditions of 0.21%sucrose ester content, 0.20% mono-glycerides content, 64.73℃ and 3.09 min was experimentally measured as 0.436. In this condition, the phenomenon of oil-water separation, is less likely to happen in the mixed-Sour Soup with high stability and better sensory quality.【期刊名称】《包装与食品机械》【年(卷),期】2017(035)004【总页数】6页(P19-23,29)【关键词】复合型红酸汤;乳化;响应面;稳定性【作者】张东亚;徐俐【作者单位】贵州大学酿酒与食品工程学院,贵阳 550025;贵州大学酿酒与食品工程学院,贵阳 550025【正文语种】中文【中图分类】TS201.1红酸汤是贵州黔东南地区苗族人民采用野生毛辣角、辣椒经自然发酵而成的调味品，研究表明，红酸汤中不仅含有Ca、P、Fe、Zn等矿物元素［1-2］，还含有酒石酸、苹果酸、乳酸、乙酸、柠檬酸和丁二酸等多种有机酸［3-4］，辣椒素、番茄红素等生理活性物质具有改善心血管功能和防癌抗癌的作用［5-6］；另外，张璇、后立琼等在对红酸汤中微生物进行分离时发现红酸汤中的优势微生物为乳酸菌［7-8］，对维持肠道微生态平衡、促进机体健康发挥着重要的作用。

三氯蔗糖-6-乙酸酯的制备

三氯蔗糖-6-乙酸酯的制备谷正艳;常虹;齐欣;曹世嘉;耿蔚华【摘要】以蔗糖-6-乙酸酯为原料,以氯化亚砜和N,N-二甲基甲酰胺(DMF)制备的Vilsimier试剂为氯化剂,合成三氯蔗糖-6-乙酸酯.探讨了氯化亚砜用量、辅助溶剂的种类、反应温度、反应时间和DMF用量对反应的影响.确定最优的反应条件为:n(氯化亚砜)∶n(蔗糖-6-乙酸酯)=7∶1、反应温度112℃、反应时间2.0h、V(DMF)∶m(蔗糖-6-乙酸酯)=8∶1(mL∶g),在此条件下,三氯蔗糖-6-乙酸酯的收率达60.2％.【期刊名称】《化学与生物工程》【年(卷),期】2014(031)005【总页数】4页(P28-31)【关键词】蔗糖-6-乙酸酯;三氯蔗糖-6-乙酸酯;Vilsimier试剂【作者】谷正艳;常虹;齐欣;曹世嘉;耿蔚华【作者单位】天津大学理学院,天津300072;天津北方食品有限公司,天津300350;天津大学理学院,天津300072;天津北方食品有限公司,天津300350;天津北方食品有限公司,天津300350【正文语种】中文【中图分类】O629.1三氯蔗糖是一种白色粉末状固体，极易溶于水，在酸性溶液中化学稳定性高，由于其甜味纯正，甜度是蔗糖的600倍［1］，不产生热能，不引起龋齿，而且经过长达10年的药理、毒理、生理理化等严格实验，证明三氯蔗糖对人是安全的［2－4］，因而具有广阔的应用前景。

三氯蔗糖－6－乙酸酯是蔗糖－6－乙酸酯与Vilsimier试剂的氯化产物，也是合成三氯蔗糖的重要中间体。

目前，国内外文献报道的三氯蔗糖－6－乙酸酯的合成方法主要通过蔗糖－6－乙酸酯与氯化试剂反应得到。

蔗糖－6－乙酸酯分子中有7个羟基，一般反应活性顺序为：6′－OH＞4－OH＞1′－OH＞2－OH＞3，3′，4′－OH，伯羟基的活性大于仲羟基，故氯化时的选择性是影响收率的主要因素。

不同氯化试剂的反应选择性及机理不同，可以分为两种类型：（1）氯化亚砜／吡啶。