三角帆蚌多糖的纯化工艺研究

利用离子交换及凝胶过滤层析方法对三角帆蚌粗多糖进行分离纯化.试验结果表明:采用弱阴离子交换色谱分离三角帆蚌粗多糖,用0.05 mol/L pH 7.9的Tris-HCl缓冲液以及0.1、0.2、1 mol/L NaCl洗脱液进行分段洗脱,得到4个组分;多糖含量较高的前2个组分经Sepharose 6B凝胶纯化,用双蒸水洗脱到2个组分,分别命名为MPa-1-1和MPa-2-1:经醋酸纤维素薄膜电泳法和高效液相凝胶色谱法鉴定,两者为均一纯多糖,测得MPa-1-1的分子质量为1589.62 kDa,MPa-2-1的分子质量为1741.80 kDa.     

桦褐孔菌多糖的分离纯化及其组成分析

为更好地开发利用桦褐孔菌这一丰富的真菌资源,采用水提法得到桦褐孔菌粗多糖(CIP),经DEAE-SepharoseCL-6B离子交换层析、SepharoseCL-6B和Sephadex G-100凝胶过滤层析得到一个桦褐孔菌多糖组分(IP2a)。采用高效液相色谱法、比旋度法及琼脂糖电泳法鉴定其纯度,气相色谱法、高效液相色谱法及红外光谱研究其组成、相对分子质量和结构。结果表明IP2a为均一组分;IP2a由鼠李糖、阿拉伯糖、葡萄糖和半乳糖组成,其摩尔比为2.3∶4.5∶1∶2.5,其相对分子质量为86053u,含有α-型糖苷键。IP2a是一种不含核酸和蛋白质的杂多糖,是桦褐孔菌水溶性多糖的重要组成。     

不同巴戟天多糖对免疫活性的影响

研究3种组分——巴戟天粗多糖MOP以及经离子交换和亲和柱层析得到的纯化多糖MOPI-3a和MOPA-2a对小鼠体内免疫活性的影响。以环磷酰胺诱导的免疫功能低下小鼠为试验对象,设10、30、50 mg/(kg.d)3个多糖水平处理,饲养10 d后观察不同巴戟天多糖对小鼠免疫器官指数、巨噬细胞吞噬率及外周血淋巴细胞转化率的影响。试验结果表明,各多糖低剂量组〔10 mg/(kg.d)〕对免疫的促进效果不明显,各多糖的中剂量组[30 mg/(kg.d)]免疫增强效果最为明显,达到或超过空白对照组的水平。各高剂量组[50mg/(kg.d)]与中剂量组相比,免疫促进活性无显著差异。在相同剂量下,3种多糖的免疫增强活性次序是MOPA-2aMOPI-3aMOP。     

浒苔多糖的纯化及抗氧化活性研究

利用DEAE-Cellulose52离子交换层析和Sepharose4B凝胶过滤层析时浒苔粗多糖进行了纯化,并采用Fenton反应和邻苯三酚自氧化法研究了粗多糖和纯化多糖EP-Ⅱ的体外抗氧化活性.结果显示,利用热水浸提、sevag法除掉蛋白质和95%乙醇沉淀后得到的粗多糖,经两步层析后可得到纯化的多糖组分EP-Ⅱ.浒苔粗多糖和EP-Ⅱ都能有效地清除羟基自由基(·OH),且均呈现一定的量效关系,当浓度为0.6mg/mL时,对羟基自由基(·OH)的清除率分别达到44%和59%.两种多糖对超氧阴离子自由基(O2-·)清除作用较弱.     

桑黄菌丝体多糖的分离纯化及理化性质分析

研究桑黄粗多糖的分离和纯化工艺,并对多糖组分进行理化性质分析。结果表明：经DEAE-52纤维素离子交换层析和Sephadex G-100凝胶过滤层析得到两个组分P-47000和P-8700;经高效液相色谱分析证明,两组分均为纯品,且不含蛋白质、核酸,为非淀粉类多糖,分子质量分别为4.74×104D和8.71×103D,均由鼠李糖、阿拉伯糖、木糖、葡萄糖、半乳糖组成,P-47000中各单糖物质的量比为3.47:1.99:1:63.27:13.44,P-8700中各单糖物质的量比为10.46:1:1.03:182.75:30.94。     

南瓜多糖的分离、纯化及抗氧化活性研究

对南瓜多糖进行提取,分离纯化。通过离子交换层析和凝胶过滤层析得到P11、P12、P213个组分,分别以清除DPPH自由基、羟基自由基和还原能力为指标,研究南瓜粗多糖及其3个组分的抗氧化活性。试验结果表明:南瓜粗多糖、P12和P21清除DPPH自由基的IC50分别为5.496、8.908、3.153mg/mL,南瓜粗多糖、P11、P12和P21清除羟基自由基的IC50分别为4.251、1.191、7.655、5.221mg/mL,南瓜粗多糖、P11、P12和P21的FRAP值依次为0.182、0.062、0.082、0.400mmol/g。     

虾夷扇贝内脏多糖SVP-12的分离纯化及性质研究

采用蛋白酶水解提取法提取虾夷扇贝内脏粗多糖。采用2步蛋白酶-sevag法脱除粗多糖中的蛋白质。粗多糖先后经Sephacryl-S 200凝胶过滤层析柱和DEAE-52阴离子交换层析柱分离得到多糖组分SVP-12。SVP-12经高效液相色谱鉴定为均一的多糖,其分子质量约为170 ku,其中多糖含量为72.05%,蛋白含量为2.74%,硫酸根含量为12.57%,氨基己糖含量为8.46%。气相色谱法检测结果表明,SVP-12含有鼠李糖、岩藻糖、阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖,其摩尔比例约为1.65∶2.54∶4.05∶5.60∶1.48∶4.90∶1.00。     

中华猕猴桃果多糖的分离纯化与抗肿瘤试验研究

从中华猕猴桃果中提取粗多糖FP，FP经阴离子交换层析得到多糖FP1和FP2。采用S180移植瘤模型，考察FP、FP1和FP2的抗肿瘤作用。结果表明，多糖FP2具有显著的抗肿瘤活性，在150mg／kg的给药剂量下，对S180肿瘤细胞的抑制率达到54．2％。凝胶过滤层析表明，FP2为单一的组分。纸层析表明，FP2含有D-葡萄糖、D-甘露糖和D-半乳糖。     

植物乳杆菌C21胞外多糖的分离纯化及其结构修饰

为研究乳酸菌胞外多糖的结构和性质,采用乙醇沉淀、DEAE- 纤维素离子交换柱层析和 Sepharose CL-6B凝胶过滤层析方法从植物乳杆菌(Lactobacillus plantarum) C21 SDM 液体培养基中分离纯化得到一种均一组分的胞外多糖,命名为PCPc。采用离子色谱和红外光谱法对其单糖组成和结构进行初步分析,结果表明,PCPc 主要由半乳糖和葡萄糖两种单糖组成,其物质的量比为1:2。并对PCPc 多糖进行化学修饰,获得了其硫酸化和磷酸化衍生物。     

不同菌种制备大豆多肽的抗氧化活性比较研究

分别采用枯草芽孢杆菌、啤酒酵母菌以及黑曲霉菌发酵豆粕制备多肽,利用SephadexG-15凝胶过滤层析、SDS—PAGE电泳等方法进一步纯化,并对各组分进行抗氧化能力的研究。结果表明：采用枯草芽孢杆菌、啤酒酵母菌以及黑曲霉菌发酵豆粕得到多肽分别为13．512、12．462、14．752mg／mL。通／LSephadexG-15凝胶过滤层析分别得到的组分1分子质量范围分布在1055．67、1374．16、675．58u,组分Ⅱ分子质量范围分布在2031．49、2283．46、1625．54u。黑曲霉菌制备多肽原液及各组分清除3种自由基的作用较强,且组分1的清除效果好于组分2,其中对脂质过氧化物清除能力大于TBHQ,并与Vc相当。     

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.