甘薯多糖SPPS-Ⅰ-Fr-Ⅱ组分的纯化及理化性质分析

甘薯经水浸提,Sevag法脱蛋白,透析,乙醇沉淀,DEAE-纤维素及Sephadex G-100色谱分离纯化得到一种白色粉末状多糖SPPS-Ⅰ-Fr-Ⅱ.经SepharoseCL-6B凝胶色谱分析证明SPPS-Ⅰ-Fr-Ⅱ为纯品.经定性化学反应鉴定表明SPPS-Ⅰ-Fr-Ⅱ不含蛋白质、核酸、酚类物质和糖醛酸,为非淀粉类中性纯粹多糖.其比旋光度[α]22D(H2O)为+115.0(c=0.8),特性粘度[η]为17.23×10-3(mL@g-1),重均分子量为53200.SPPS-Ⅰ-Fr-Ⅱ完全酸水解后纸层析及气相色谱分析确定糖基组成为葡萄糖.     

山药多糖RDPS-Ⅰ组分的纯化及理化性质的研究

山药经水浸提分离,浸提液脱蛋白,透析,乙醇沉淀物经DEAE-52纤维素及Sephdex G-100色谱纯化得白色粉末状多糖RDPS-I.Sepharose CL-6B凝胶色谱分析表明RDPS-I为多糖纯品.定性化学反应表明RDPS-I不含核酸、蛋白质、酚类物质和糖醛酸,是一种非淀粉类中性纯粹多糖,比旋光度[α]22 D(H2O)为+188.4(c=0.8),特性粘度[η]为16.48×103(mL/g),相对分子质量为42 200,完全酸水解后纸层析及气相色谱分析确定RDPS-I的糖基组成为葡萄糖、甘露糖和半乳糖,摩尔比为10.370.11.     

山药多糖RDPS-I组分的纯化及理化性质的研究

山药经水浸提分离 ,浸提液脱蛋白 ,透析 ,乙醇沉淀物经DEAE -5 2纤维素及SephadexG -10 0色谱纯化得白色粉末状多糖RDPS -I。SepharoseCL -6B凝胶色谱分析表明RDPS -I为多糖纯品。定性化学反应表明RDPS -I不含核酸、蛋白质、酚类物质和糖醛酸 ,是一种非淀粉类中性纯粹多糖 ,比旋光度 [α] 2 2D(H2 O)为 +188 4(c =0 8) ,特性粘度 [η]为 16 48× 10 -3 (mL/g) ,相对分子质量为 42 2 0 0 ,完全酸水解后纸层析及气相色谱分析确定RDPS -I的糖基组成为葡萄糖、甘露糖和半乳糖 ,摩尔比为 1∶0 37∶0 11。     

余甘多糖分离纯化及其分子结构的研究

分离纯化余甘多糖(Pe Ps),并研究其理化性质和结构特征。采用热水浸提法提取余甘粗多糖,经DEAESephadex A-25柱层析分离得到两种不同多糖组分。综合运用硫酸-苯酚、硫酸-咔唑、碘-碘化钾等化学分析方法对多糖的理化性质进行分析;采用高效液相色谱法鉴定组分的均一性及其分子量(Mw),并用气相色谱法测定组分的单糖组成;利用紫外光谱、红外光谱、旋光度研究多糖组分的结构特征。结果表明:余甘粗多糖经纯化分级后得到两种均一的多糖组分:Pe PsⅠ和Pe PsⅡ。经鉴定,Pe PsⅠ为含有吡喃的中性还原糖,而Pe PsⅡ为含有糖醛酸的吡喃酸性还原糖;两者对热稳定,不溶于有机溶剂,不含蛋白质和氨基酸;比旋光度[α]D20分别为+68°、+108°;分子量分别为1.49×105、1.51×105u。Pe PsⅠ主要是由L-鼠李糖、L-阿拉伯糖、D-木糖等5种单糖构成;而Pe PsⅡ主要是由L-鼠李糖、L-阿拉伯糖、D-半乳糖3种单糖构成。     

桑黄多糖分离纯化及其结构初步鉴定

本文用离子交换和凝胶层析对桑黄多糖进行了纯化,并对多糖的结构、组成及理化常数进行了分析。结果表明,经弱碱性阴离子和弱酸性阳离子交换树脂一次串联脱蛋白,蛋白脱除率达94.96%,多糖回收率为77.77%。再经凝胶层析,得到大分子量多糖组分HHM(2.84×106Da)和小分子量多糖组分HLM(5.33×104Da),HLM和HHM的旋光度分别为[α]D25= 64.8°和[α]D25= 58.4°,由IR分析,初步推测该HHM和HLM多糖为β型吡喃多糖,由TLC法测得的HHM的单糖组成为葡萄糖,HLM单糖组成分别为葡萄糖和半乳糖。     

柳蒿芽多糖的分离纯化及结构初步分析

柳蒿芽干品经热水浸提,所得多糖分别经脱蛋白、脱色、乙醇沉淀、DEAE 纤维素和SephadexG-100 凝胶层析柱分离纯化,得到3 种多糖组分(PSWP-1 ﹑ PSWP-2 和PSWP-3),经过高效液相色谱分析表明：PSWP-1 相对分子质量为1.1513 × 105D,水解单糖由鼠李糖和葡萄糖组成,摩尔比为1.000:1.703;PSWP-2 相对分子质量为1.2491 × 105D,水解单糖由葡萄糖组成;PSWP-3 相对分子质量为1.1663 × 105D,水解单糖由鼠李糖和葡萄糖组成,摩尔比为1.000:2.189。红外光谱分析表明,3 种多糖组分均为一种β- 型糖苷键相连的吡喃多糖。     

白灵菇菌丝体多糖的分离纯化及理化性质研究

研究白灵菇菌丝体粗多糖的分离纯化技术,并对得到的多糖进行纯度鉴定及理化性质研究.结果表明,白灵菇菌丝体多糖(PNMP)经DEAE-Cellulose 52和Sephadex G-200柱层析后得到单一组分PNMPⅢ-a,经分析鉴定,PNMPⅢ-a为不合双糖、糖醛酸和核酸的非淀粉类的均一多糖;其相对分子质量为15213Da.PNMPⅢ-a完全酸水解后,经高效液相色谱分析确定其糖基的组成为葡萄糖(Glc)、鼠李糖(Rha)、木糖(Xyl)和核糖(Nbo).红外光谱分析表明,PNMPⅢ-a是一种含有氨基、硫酸酯键、β-糖苷键和α-D葡萄糖的蛋白多糖.     

沙蒿籽中两种水溶性胶多糖的分离纯化与免疫活性研究

为研究沙蒿(Artemisia sphaerocephala Krasch)籽中的水溶性多糖成分,经热水提取、醇沉、脱蛋白得到水溶性沙蒿籽胶粗多糖CASPs(crude Artemisia sphaerocephala Krasch seed gum polysaccharides),CASPs经DEAE-Cellu-lose柱层析分离得到ASPI、ASPII、ASPIII、ASPIV四个多糖组分,ASPI经Bio-Gel P-150柱层析纯化后得到ASPI-A,ASPⅢ经Sephadex G-75柱层析得到ASPⅢ-A,ASPⅢ-B,ASPⅢ-C三个组分。气相色谱分析表明,ASPI-A由阿拉伯糖、甘露糖、葡萄糖及半乳糖组成,它们之间的摩尔比为1:2.84:4.89:1.92;ASPⅢ-A由木糖及微量的鼠李糖、阿拉伯糖、葡萄糖、半乳糖、葡萄糖醛酸及半乳糖醛酸组成。高效凝胶渗透色谱(HPGPC)分析表明,ASPI-A为均一性多糖,平均相对分子质量为5.42×104D;ASPⅢ-A的相对分子质量大于4×105D。免疫活性实验结果表明,与Con A合用时,ASPI-A和ASPⅢ-A在一定浓度范围内对小鼠脾细胞增殖反...     

五味子多糖的提取及分离

五味子是一种具有广阔开发前景的传统中药材。实验中,以五味子为原料,利用水提醇沉法得到了五味子粗多糖。在料液质量体积比为1 g∶32 mL,浸提温度99℃,提取时间4 h的适宜的提取工艺条件下,粗多糖的提取率达5.61%。采用酶法与Sevag法联用脱除粗多糖中蛋白质效果较好。利用凝胶色谱柱层析法对多糖半纯品进行分级分离,得到了两种多糖Ⅰ和Ⅱ。经薄层色谱分析,初步确定了两种多糖的单糖组成,又通过红外光谱分析,证明多糖Ⅰ可能为α-呋喃糖,多糖Ⅱ可能为β-吡喃糖。     

古尼虫草多糖硫酸酯化修饰及其抗氧化活性

对古尼虫草多糖进行硫酸酯化修饰(修饰后命名为SPS70),并对修饰后的多糖进行了结构、性质及活性研究.红外光谱分析表明SPS70已具备硫酸酯化多糖的硫酸根基团.研究表明修饰后多糖由中性多糖变为酸性多糖.通过高效液相色谱分析发现,经过DEAE-SephadexA-25分离纯化后,SPS70纯度达到92.72％,抗氧化活性...     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.