荞麦黄酮类化合物的提取分离及结构鉴定

采用正交设计对荞麦黄酮提取工艺条件进行筛选得到荞麦的最佳提取条件为65%的乙醇、物料比1∶15在50～55℃温度下提取6h。在最佳提取条件下进行不同荞麦原料提取显示,苦荞粉黄酮得率最高为2.5%,其次为苦荞壳,甜荞粉得率最低。对荞麦黄酮提取浓缩液进行薄层分离,得到与芦丁和懈皮素结构相近的两种黄酮类物质;定性显色结果显示荞麦中的黄酮类物质包括黄酮醇、5-羟基黄酮或2-羟基黄酮等化合物。     

洋葱中黄酮苷的提取及抗氧化稳定性研究

探讨洋葱中黄酮苷的提取工艺,以及pH值、温度和光照条件对洋葱黄酮苷抗氧化稳定性的影响.结果表明:洋葱用40倍75%的丙酮溶液,在60℃条件下提取1 h为最佳提取方法;洋葱中黄酮苷在微酸性条件下的抗氧化性质比较稳定;在70 ℃以上条件下保存1 h基本失去抗氧化活性;洋葱中黄酮苷对光线敏感.     

响应面法优选生姜中黄酮提取工艺研究

目的:本试验以生姜为原料,采用索氏提取法提取黄酮并测定其提取率。方法:通过对索氏提取时间、固液比、乙醇浓度、提取温度等单因素试验,确定最佳单因素水平并做响应面优化试验,确定了以乙醇为提取剂提取生姜中黄酮类化合物的最佳工艺条件。然后采用紫外分光光度法测定黄酮的提取率。结果:最佳提取工艺为索氏提取时间4.02h,乙醇浓度66.4%,提取温度96.65℃,固液比1∶39.9。采取紫外分光光度法进行测定得:回收率为98.98%,精密度为3.3%,生姜中黄酮提取率为1.611mg/g。结论:采用响应面优化处理方法可靠性强,紫外分光光度法测定生姜中黄酮的方法比较准确、可行。     

金银花中黄酮类物质最佳提取工艺的研究

采用水提法、醇提法、超声波法探讨了从金银花中提取黄酮类化合物的最佳工艺条件。实验结果表明，超声波法的提取效果最好，即在60倍于样重的40％的乙醇浸泡24h，之后再用超声波下提取45min，其黄酮浸出量为16．91％。     

沙棘叶黄酮的提取及其对抗氧化性的影响

目的:利用不同溶剂对沙棘叶黄酮进行提取,研究沙棘叶黄酮的提取及其对抗氧化性的影响,综合提取温度和时间,确定常规条件下提取沙棘叶中抗氧化成分的最佳条件,为沙棘叶抗氧化性的研究提供依据。方法:采用紫外-可见光分光光度法,以芦丁作为对照品,进行检测实验。结果:溶剂对沙棘叶黄酮的提取率、抗氧化性影响较大。结论:沙棘叶中抗氧化物质的最佳提取条件为在30℃下,用80%(v/v)甲醇溶液提取4h。     

红薯叶黄酮分离纯化工艺及抗氧化性研究

本实验以红薯叶为原料,研究了黄酮类化合物分离纯化工艺,并研究了粗提物与纯化产物对羟基自由基、1,1- 二苯基-2- 苦基肼自由基(OPPH·)的清除作用。结果表明,红薯叶黄酮最佳提取工艺为60% 乙醇水溶液90℃回流提取60min,料液比1:40,粗提物中总黄酮含量为101.3mg/g。提取液用HPD500 大孔树脂进行纯化效果好,最佳纯化工艺为：吸附条件：上样原料液黄酮含量1.8mg/ml,pH3 上样流速为3BV/h;洗脱条件：50% 乙醇、流速3BV/h,流量4BV,在此条件下,纯化产品黄酮含量为488.7mg/g;粗提物与纯化产物均具有对自由基的清除作用,是一种有效的天然抗氧化剂新资源。     

生姜乙醇提取物在猪油中的抗氧化作用研究

生姜作为一种常用的香辛料,具有一定的抗氧化作用。本结合正交试验采用直接水浴浸提,初步研究了不同因素、不同水平下生姜抗氧化物的最佳提取条件,即固液质量比1：10,乙醇浓度（50％、60％、70％、80％、90％、95％）,浸提温度（40℃,50℃,60℃）,浸提时间（4h,6h,8h)。并且将最佳条件下的提取物以不同的浓度加入到猪油底物中,同时与抗坏血酸、酒石酸、柠檬酸作协同作用研究,在60℃烘箱中加速氧化保存后,用Na2S2O3-I2滴定法测定生姜乙醇提取物对猪油的抗氧化作用。结果表明：生姜直接水浴浸提的最佳提取条件是,在固液质量比1：10的条件下。乙醇浓度为60％,浸提温度为50℃,处理时间为4h;所有添加的生姜乙醇提取物对猪油都具有良好的抗氧化性能,并且添加猪油质量的0．15％时抗氧化效果最佳;与酒石酸、抗坏血酸、柠檬酸的协同作用不明显。     

山楂叶黄酮的超声提取、精制及抗氧化性研究

通过单因素实验和正交实验设计探讨了山楂叶黄酮的超声辅助提取工艺条件，采用溶剂萃取法对粗提物进一步除杂精制，并对提取物的抗氧化性能进行了研究。实验结果表明：山楂叶黄酮的最适宜提取工艺是温度80℃～85℃，液料比（乙醇体积：原料质量）18：1，用60％乙醇超声提取2次，每次40min，然后再70℃，回流提取1h。精制后。黄酮在甲醇：水：丙酮1：2：2体系中进行聚酰胺薄层色谱分离效果最好，得到4个黄酮斑点。山楂叶黄酮对猪油抗氧化能力较强，Vc具有很好的正协同效应。     

甘草渣中黄酮和多糖的提取及含量测定

本文以提取甘草酸后的甘草渣为原料，分别以乙醇和水为溶剂，采用超声辅助提取法提取甘草黄酮和多糖，通过正交设计实验，筛选出最佳提取条件，用紫外分光分光光度法测定黄酮和多糖的含量。结果表明：甘草渣中黄酮类化合物的最佳提取条件为：超声时间75（25，25，25）min，提取温度45℃，乙醇浓度80％，固液比1：12，提取3次，甘草黄酮的含量为2．69％。甘草多糖的最佳提取条件为：超声时间75（25，25，25）min，超声温度65℃，固液比为1：12，提取次数3次，甘草多糖的含量为7．89％。     

八角茴香总黄酮提取工艺研究

以八角为原料,研究乙醇回流法提取八角总黄酮。采用单因素和正交实验确定八角黄酮的最佳提取条件。结果:八角黄酮最佳提取条件为乙醇体积分数60%、提取时间2h、料液比1∶40、提取温度80℃。结论:在最佳工艺条件下,八角总黄酮得率为13.34%。     

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.