繁缕叶蛋白提取工艺研究

以鲜繁缕为材料,采用酸化和加热相结合的方法,研究了提取繁缕叶蛋白的最佳工艺条件。在考虑料液比、滤布层数、加热温度和加热时间等单因素对叶蛋白提取率影响的基础上,进行了正交试验,最终确定叶蛋白最佳提取工艺条件为：料液比1:5、5 层滤布过滤、加热到75℃并在此温度下持续11min,繁缕叶蛋白的提取率为52.08%,得率为27.17%。     

箬竹叶绿素的提取及改性研究

通过正交实验对箬竹叶中叶绿素的提取工艺、叶绿素的稳定性以及叶绿素锌钠的制备工艺进行了研究。结果表明：微波辅助提取箬竹叶中叶绿素的最佳工艺条件为微波加热120s、物料配比（箬竹叶：复合提取液）1：6、提取液的pH为11、提取液中乙醇体积分数为30％。制备叶绿素锌钠最佳工艺条件为ZnSO4浓度为10％、箬竹叶粉与ZnSO4配比（g：mL）为5：15、锌代温度为70℃、锌代时间为2h。     

辣木叶总黄酮乙醇提取工艺的研究

对辣木叶中总黄酮的乙醇提取工艺进行了研究。探讨乙醇浓度、浸提温度、料液比、浸提时间、浸提次数对辣木叶中总黄酮提取效果的影响，在单因素试验的基础上,通过正交试验确定最佳提取工艺条件。结果表明：辣木叶中总黄酮类物质的最佳提取条件为70％的乙醇溶液作提取剂，提取温度60℃，料液比1：20，提取3次，每次1h，在此条件下，提取液中的总黄酮含量达到3．95％。     

桑叶叶蛋白提取工艺的研究

对桑树叶蛋白提取条件的优化进行了研究。结果表明，桑树叶蛋白提取的优化工艺条件为：室温下，以水为浸提荆，打浆时间3min，浸提时间4min，料液比1：5（叶片重比浸提剂体积，即g：m1），漫挺剂pH值8．0，絮凝温度75℃，调节提取液pH为5．0、8．0和13．0得到沉淀物，在60℃干燥。该工艺提取桑树鲜叶叶蛋白得率为：5．17％。     

超声辅助提取石榴叶中总黄酮工艺的研究

以石榴叶为原料,采用乙醇作为提取溶剂,在超声辅助下提取石榴叶中总黄酮。探讨了超声功率、乙醇体积分数、料液比、提取时间等因素对总黄酮得率的影响。结果表明,超声辅助法从石榴叶中提取总黄酮的适宜工艺条件为：乙醇体积分数70％,功率350W,提取时间16min,料液比1：10。此条件下石榴叶中总黄酮提取得率为0．38％。     

响应面分析法优化杜仲叶桃叶珊瑚甙提取工艺条件

目的：研究杜仲叶桃叶珊瑚甙提取的最佳工艺条件；方法：利用响应面分析法（Response Surface Methodology）对杜仲叶中桃叶珊瑚甙的提取工艺进行优化，在单因素实验基础上选取实验因素与水平，根据中心组合（Box—Benhnken）实验设计原理采用3因素3水平的响应面分析法，依据回归分析确定各工艺条件的影响因子，以桃叶珊瑚甙提取率为响应值作响应面和等高线，在分析各个因素的显著性和交互作用后，得出杜仲叶桃叶珊瑚甙浸提的最佳工艺条件；结果：杜仲叶桃叶珊瑚甙提取的最佳工艺条件为：乙醇浓度70％，料液比1：13，浸提温度70℃，浸提时间40min；浸提3次，杜仲叶桃叶珊瑚甙的实际提取率可达1.808％。     

树莓叶黄酮类物质提取工艺条件优化

采用单因素实验和正交实验,研究微波提取法提取树莓叶中的黄酮类物质最佳提取工艺条件,结果表明：微波提取法提取树莓叶中总黄酮的最佳提取条件为：提取时间3min,料液比1g：40mL,乙醇体积浓度50％,功率250W,得率为5．81％。     

马齿苋籽粕蛋白的提取及分离纯化

以脱脂马齿苋籽粕为原料,提取率为考察指标,通过单因素和正交优化试验确定碱溶酸沉法制备马齿苋籽粕蛋白的最优工艺条件;使用蛋白层析仪通过阴离子交换层析对粗蛋白进行初步分离纯化。结果表明:马齿苋籽粕蛋白最优提取工艺为,液料比25∶1、p H值12、温度50℃、时间20 min,马齿苋籽粕蛋白提取率达56.04%,蛋白含量(以蛋白质含量计)达58.53%;马齿苋籽粕蛋白等电点为4.0;最优纯化工艺为,上样量3 m L、洗脱液流速0.4 m L/min,纯化后马齿苋籽粕蛋白含量达91.02%,比纯化前提高了32.49%。     

马齿苋多糖的提取与纯化研究

为确定马齿苋多糖的提取与纯化工艺条件,该研究采用超声波辅助法提取马齿苋多糖;Sephadex G-100柱层析对其进行纯化.结果表明,马齿苋多糖的最佳提取工艺为:超声波功率130W,提取时间55min,提取温度75℃,液料比45∶1,多糖的平均得率为13.28％;通过SephadexG-100柱层析获得3个马齿苋多糖亚级分,收集第一亚级分后得到马齿苋多糖-a为分子量分布均一组分;成分鉴定结果表明,马齿苋多糖-a为含蛋白质的酸性多糖,不含淀粉和还原糖.     

马齿苋多糖提取、纯化工艺的初步研究

实验以多糖提取率为指标成分，采用正交试验对马齿苋多糖的提取工艺进行优选，并进行了初步纯化。结果显示最佳工艺为：温度100℃，时间9h，醇沉比4：1，浸提次数3次，在最佳提取工艺时，马齿苋的多糖提取率为268％用光谱分析鉴定初步纯化的多糖：红外光谱分析具有典型的多糖特征吸收峰，紫外光谱分析未见蛋白质（280nm）与核酸（260nm）的特征吸收峰。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status