羟化赖氨酸清除活性氧自由基能力的研究

在竹叶及其提取物中检出了一种特殊的非蛋白氨基酸δ－ＯＨ－Ｌｙｓ，为了解其生物学意义，用化学发光法和电子自旋共振法（ＥＳＲ）对δ－ＯＨ－Ｌｙｓ和Ｌｙｓ清除超氧阴离子自由基（Ｏ２－）的能力作了比较，结果表明赖氨酸在δ位羟化以后，抗活性氧自由基的活性有了显著提高。     

红麻韧皮部和木质部纤维素酶木素的特性

用纤维素酶水解的方法从红麻韧皮部和木质部分离出红麻韧皮纤维素酶木素和红麻木质纤维素酶木素。通过元素分析、功能基含量测定以及碱性硝基苯氧化产物和酚酸的ＨＰＬＣ分析，ＩＲ，ＵＶ．＇Ｈ－ＮＭＲ和１３Ｃ－ＮＭＲ波谱分析，认为红麻韧皮纤维素酶木素属于ＧＳ型木素，其摩尔比为Ｇ：Ｓ＝１：１．８７，而红麻木质纤维素酶木素属于ＧＳＨ型，其摩尔比为Ｇ：Ｓ：Ｈ＝１：１．０３：Ｏ．２６。它们的Ｃ９单元式分别为Ｃ９Ｈ７．３８Ｏ３．４６（ＯＣＨ３）１．３４和Ｃ９Ｈ７．５２Ｏ３．００（ＯＣＨ３）１．２２。研究表明，在红麻韧皮纤维素酶木素中不存在酚酸酯或醚连接，而８１％的对香豆酸和９０％的阿魏酸可在红麻木质纤维素酶木素碱水解中除去，红麻木质纤维素酶木素比红麻韧皮纤维素酶木素缩聚度高。这两种纤维素酶木素的得率均高于７５％（占相应原料中Ｋｌａｓｏｎ木素含量），这无疑在木素研究中具有更好的代表性。     

棉仁蛋白粉的营养评价

通过对“乙醇一己烷混合溶剂浸出工艺”生产的棉仁蛋白粉化学成份分析表明，棉仁蛋白粉是一种高蛋白（５０．２％）、低纤维（５．０％）、低毒性（３８８ｐｐｍＦＧ）的蛋白质原料，富含Ｐｈｅ（３．１％）、Ａｒｇ（６．１％）、Ｍｅｔ＋Ｃｙｓ（２．１％），Ｌｙｓ为第一限制性氨基酸，ＡＬｙｓ（有效赖氨酸）仅为总Ｌｙｓ的７０％，棉仁蛋白粉低Ｃａ（０．１７％）、高Ｐ（１．０４％）、低Ｍｎ（１５ｐｐｍ），富含Ｆｅ（２６４ｐｐｍ）、Ｚｎ（８９ｐｐｍ）、Ｃｕ（３０ｐｐｍ）。采用Ｓｉｂｂａｌｄ法评定其生物学价值。ＴＡＡ表观消化率为７５％，ＣＰ、ＴＡＡ真消化率为８０％、８２％，ＴＭＥ、ＡＭＥ分别为１１．８８ＭＪ／Ｋｇ、９．２７ＭＪ／ｋｇ。可见，ＣＫＰＦ的生物学价值较高。     

高效液相色谱法测定大豆提取物中大豆异黄酮的含量

本文建立了大豆提取物中大豆异黄酮的高效液相色谱测定方法,通过正交试验了样品水解最佳条件为１．０ｍｏｌ／ｌ ＨＣｌ－ＭｅＯＨ溶解,８０℃下,回流水解０．５ｈ,采用Ｎｏｖａ－Ｐａｋ Ｃ１８ ３．９＊１０ｍｍ４μｍ色谱柱ＭｅＯＨ－０．４％Ｈ３ＰＯ４（４７：５３Ｖ／Ｖ）为流动相,流速０．７ｍｌ／ｍｉｎ检测波长２６０ｎｍ等色谱条件下测定甙元含量,通过换算因子计算大豆异黄酮的含量。该方法快速,灵敏、重理性好,     

麦草NaOH—AQ浆高白度无氯和低氯漂白新工艺的研究

提出了一种高白度无氯漂白（ＬＲＰＰ）和低氯漂白（ＬＲＰＨ）新工艺。麦草ＮａＯＨ－ＡＱ浆经１％ＬＲ进行脱木素预处理，可以使卡伯值降低５７．３％，而粘度仅下降１６．６％。ＬＲ脱木素预处理后的纸浆具有良好的可漂性。经１％ＬＲ－２％Ｈ２Ｏ２－２％Ｈ２Ｏ２无氯漂白和１％ＬＲ－２％Ｈ２Ｏ２－２％Ｃａ（ＣｌＯ）２低氯漂白，可分别获得８８．１％ＳＢＤ和８８．３％ＳＢＤ的高白度纸浆，且具有较高的粘度。对ＬＲＰＰ和ＬＲＰＨ漂白浆的研究表明，二者的物理性能均优于传统的ＣＥＨ三段漂。     

木薯渣生料发酵生产单细胞蛋白的研究

研究了在木薯渣中接入有较强生淀粉分解能力的根霉Ｒ２和蛋白含量高的酵母Ａｓ２．６１７进行混合发酵生产蛋白饲料。使原料粗蛋白从３．９％提高到２２．４３％，产品的氨基酸总量为１５．０２％。并找出较合适的发酵条件为：发酵温度为２８～３２℃，ｐＨ为自然，尿素用量为０．５％，ＭｇＳＯ４·７Ｈ２Ｏ０．０５％，ＫＨ２ＰＯ４０．０５％。     

高活性高酒精产率产酯酵母菌株的选育

本文通过测定选择Ａａｃｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ１３００和Ｈａｎｓｅｎｕｌａａｒｏｍａｌａ１３１２做为亲本，利用细胞融合技术使其杂交获得成功。利用不可逆生化抑制剂碘乙酸（０．１％）处理Ｈ．ａｒｏｍａｌａ１３１２的原生质体４０分钟，使其１００％不能再生，与Ｓ．ｃｅｒｅｖｉｓｉａｅ１３００（ａ）融合后，在融合子中表达了Ｈ．ａｎｏｍａｌａ１３１２的性状，如同化ＫＮＯ＿３等。融合子ＦＳＨ－１２在１２Ｂｘ米曲汁发酵中酒精为６．２％（ｗ／ｖ），产乙酸乙酯０．４０９％（ｗ／ｖ），同化硝酸盐。在产孢培养基上不形成孢子。酒精的耐受力为１０．５％（ｖ／ｖ），在ｐＨ３时生长良好，并能产酯。经固态发酵实验，证明该融合子能够适应酒醅中的环境，因此，ＦＳＨ－１２具有一定的实用意义。     

里氏木霉 Rut C-30 液态发酵法生产纤维素酶

探讨了增强里氏木霉ＲｕｔＣ－３０产纤维素酶的方法，添加葡糖糖于培养基中，可促进菌体生长，但不能提高产酶；采用Ａｖｉｃｅｌ与麸皮复合碳源，以及使用ＫＨ２ＰＯ４－Ｋ２ＨＰＯ４缓冲系统控制发酵液ｐＨ，在摇瓶发酵条件下，可获得很高活力的纤维素酶，培养６ｄ，酶活可达到ＣＭＣａｓｅ１６６７～２０８４ｎｍｏｌ·ｓ－１·ｍｌ－１，ＦＰＡ１５０～２００ｎｍｏｌ·ｓ－１·ｍｌ－１．采用２．５Ｌ发酵罐培养，通过控制ｐＨ和溶氧，纤维素酶活力为ＣＭＣａｓｅ２２２３．８ｎｍｏｌ·ｓ－１·ｍｌ－１，ＦＰＡ１９４．５ｎｍｏｌ·ｓ－１·ｍｌ－１．     

Lycra~ soft弹性纤维

Ｌｙｃｒａ○Ｒｓｏｆｔ是１９９６年杜邦公司以Ｌｙｃｒａ○ＲＴ９０２Ｃ为授权品牌的一种新型弹性纤维，Ｌｙｃｒａ○Ｒｓｏｆｔ可增加服装的服用性、舒适性及对人体运动的自如性。图１为Ｌｙｃｒａ○Ｒｓｏｆｔ纤维的拉伸性能曲线，该应力－应变曲线表现出Ｌｙｃｒａ○Ｒｓｏｆｔ纤维具有其它氨纶丝所不具有的更大的伸长、容易伸展和优异回弹的性能。图１　Ｌｙｃｒａ○Ｒｓｏｆｔ的应力—应变曲线Ｌｙｃｒａ○Ｒｓｏｆｔ使纤维制品穿着柔软舒适、自然飘逸，同时，对纺织加工中的张力反应较不敏感，更加增强了纺织加工的适应性，使其在纺…     

内硝基冠醚中间体的合成

研究了作为制备新型内硝基冠醚原料的中间体２－硝基－１，３－苯二酚（ＮＢ）及多甘醇双对甲苯磺酸酯（ＯＥＤＴ）的合成．通过改进ＮＢ的合成条件，使磺化、硝化、水解三步总收率由１２．９％提高到３７．５％；以吡啶为溶剂和ＨＣｌ的束缚剂，控制反应物摩尔比为ＴｓＣｌ∶ＯＥＧ＝２．０６∶１．００，在０℃～５℃反应２ｈ后，加入适量水静置过夜，可明显提高ＯＥＤＴ的收率和纯度．     

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