不同溶剂和超滤浓缩倍率对甘薯蛋白提取及纯度的影响

探索了不同的提取溶剂和超滤对甘薯蛋白提取的效果。结果表明：与NaCl溶液和氢氧化钠溶液相比,蒸馏水更适合提取甘薯蛋白。超滤浓缩倍率与浓缩液中蛋白含量和制得蛋白粉纯度呈线性正相关（p≤0.01）。     

甘薯浆液的放置时间对甘薯分离蛋白品质的影响

通过分析从放置不同时间的甘薯浆液提取出的甘薯分离蛋白中各组分（粗蛋白、粗纤维、粗脂肪、水分、灰份、总糖）含量、氨基酸组成、SDS-PAGE和色泽，研究放置时间对甘薯分离蛋白产品质量的影响。结果表明，随着放置时间的延长，提取的甘薯分离蛋白品质明显下降，其中蛋白含量呈显著降低趋势，有大分子量聚合物生成，颜色变暗，营养价值降低。     

甘薯淀粉加工废液中蛋白回收技术

技术简介 该技术以汁薯提取淀粉后的废液为原料，经过离心、浓缩、变性以及喷雾干燥处理．最终得到蛋白含量超过60％的甘薯蛋白粉。     

甘薯可溶性蛋白的分离提取及特性研究

通过调节pH值和离心分离的方法，从”玉丰”甘薯汁液中快速地分离提取出可溶性甘薯蛋白（Ipomoein），然后应用生物化学方法，对冷冻干燥的甘薯蛋白粉末进行了分析。结果表明：随着pH值的增加，离心后得到的沉淀率逐渐降低。当pH值为4时，获得的最大沉淀率为7.8％，而此时上清中可溶性蛋白的含量降至最小，为2．9mg／mL。当pH值为4和4.5时，未经透析的沉淀悬浮液在冷冻干燥后，所舍的可溶性蛋白分别为41.5％和45．5％；经过透析，粉末中的可溶性蛋白的含量明显增加，分别达到了58.9％和69.0％。此外，与透析前相比，透析后的可溶性甘薯蛋白呈现出了多孔构造。在非还原条件下，电泳显示出甘薯可溶性蛋白存在着三种不同的分子形式：22kDa，31kDa及50kDa；但在还原条件下，只显示出25kDa一种蛋白分子形式，说明这三种蛋白质分子之间是通过S—S联结而成的。然而，PAS染色实验未能显示它们是糖蛋白。     

高米蛋白含量粉末油脂的制备研究

通过正交试验酶法提取米渣蛋白，确定了最佳的提取工艺，所制蛋白粉蛋白质含量为80．1％，得率55．6％，溶解性好；将所得蛋白粉用于制作微胶囊壁材，制备了高蛋白含量粉末油脂，并对产品进行了检测、电镜扫描与评价。结果表明，所制得的粉末油脂蛋白质含量为26．5％、脂肪含量为26．7％、表面油含量为2．5％、包埋率为95．1％。微胶囊表面光滑、且复原乳液无分层、无粒子挂壁现象，各项指标均达到了饲用奶粉的要求。     

正交试验优化花生蛋白提取工艺及低脂花生蛋白饮料的研制

以脱皮花生为原料,利用水剂法提取花生蛋白,然后将得到的富含花生蛋白的水相作为基料制备低脂花生蛋白饮料。从粉碎程度、料液比、浸提温度和浸提时间4个方面考察提取条件对花生蛋白提取率的影响,结果表明:将脱皮花生粉碎至平均粒径26μm左右,在料液比1∶5(g/m L)和60℃的条件下提取2 h,最终水相的蛋白质含量为50.4 g/L,花生蛋白提取率达到76.04%。同时以上述富含花生蛋白的水相为基料制备低脂花生蛋白饮料,考察碳酸氢钠对饮料色泽和稳定指数的影响以及乳清蛋白粉对饮料色泽、口感和氨基酸组成的影响。结果显示:0.1 g/L的碳酸氢钠可有效提高产品的稳定性,加入5.0 g/L乳清蛋白粉可明显改善低脂花生蛋白饮料的润滑度并提高产品的营养价值。该工艺制备得到的低脂花生蛋白饮料的蛋白质含量为21.0 g/L,脂肪含量为1.2 g/L,具有良好的稳定性。     

复合酶法提取花生蛋白的工艺优化及性能评估

采用多种酶对花生进行分步水解制备蛋白粉。以花生为原料，蛋白提取率为响应值，酶添加量、温度、pH为实验因素，采用响应面建立数据模型，优化提取工艺，并将该条件下制备的蛋白粉和水提法、单一酶提取法制备样品与市售蛋白进行功能性对比，研究复合酶提取蛋白粉的粒径分布、溶解性、乳化性、表面疏水性的变化。结果表明：复合酶的最优酶解条件为酶添加量1.8%、反应温度55 ℃、适宜pH9.2，在此条件下蛋白提取率达到89.21%。复合酶制备的蛋白粉粒径分布均匀，颗粒物更小，蛋白溶解性和乳化性都显著提高。     

血浆蛋白粉产品品质分析与比较

采集市场上占有率较高的14种畜禽血浆蛋白粉,分析比较了产品的色泽、常规成分、凝胶质构、保水性、蛋白质组成、矿物质元素含量等,确定了血浆蛋白粉产品品质现状与差异,为血浆蛋白粉产品品质提升和食品级血浆蛋白粉标准的制定提供数据支持。结果表明:不同企业生产的血浆蛋白粉产品在外观(粉质、色度)和产品品质(粗蛋白、粗灰分、水分、水不溶物含量、凝胶质构和保水性、矿物质元素种类及含量)上存在显著差异(P0.05),并且饲料级血浆蛋白粉与食品级血浆蛋白粉的差异较大。通过相关性分析发现,提高灰分、Na、Mg、Ca含量可提高血浆蛋白凝胶的弹性,提高Mg、Ca含量可提高血浆蛋白凝胶的保水性。     

冲出蛋白粉的补充误区

蛋白粉是一种营养补充剂，主要成分为蛋白质，包括牛奶酪蛋白、乳白蛋白、大豆蛋白游离物，是一种利用现代生物技术提取、加工的纯天然高营养、高蛋白食品。市场销售的蛋白粉里，蛋白质含量的标示值均在60％以上。绝大多数蛋白粉都是用大豆深加工而成的，普通的去皮脱脂大豆粉蛋白质含量在50％左右．经过浓缩的可达到70％左右，浓缩后再深加工生产出的分离蛋白，其蛋白质含量可高达90％以上。     

甘薯淀粉加工废液实现再利用

中国农业科学院首次采用酸沉和超滤的工艺，从甘薯淀粉加工废液中提取出纯度达85％以上的甘薯蛋白粉。     

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.