响应面法优化米糠蛋白提取工艺

采用响应曲面法建立了米糠蛋白提取率的二次多项数学模型,并考察不同pH值、温度、提取时间对米糠蛋白提取率的影响,米糠蛋白提取率的最优工艺参数为pH值9,温度39℃,提取时间1．7h,米糠蛋白的提取率为80．97％。     

碱溶性米糠多糖的提取及其免疫调节功能研究

本文研究了不同提取温度、提取时间和碱摩尔浓度对碱溶性米糠多糖提取得率的影响。采用响应面分析的方法得到碱溶性米糠多糖的最佳提取条件为：温度44．5℃，时间2．13h，NaOH浓度0．53mol/L。并在此基础上，采用动物试验证明碱溶性米糠多糖具有免疫活性增强作用。     

膨化米糠中多糖的酶法提取研究

研究了酶解温度、酶解时间、酶用量、pH值对膨化来糠中多糖的提取得率及活性的影响.试验表明.各因素对提取得率影响大小依次为pH值、酶解温度、酶解时间、酶用量;对米糠多糖活性影响最大的是pH值,在酸性或碱性环境下提取的多糖活性都低.建立的回归模型较好地拟合了多糖得率与各因素之间的关系.结合多糖得率及活性测定,利用期望函数途径进行模拟选优,并进行验证.     

微波辅助浸提米糠多糖工艺研究

采用微波辅助水浸提米糠多糖,分别考查液料比、pH值、微波功率、提取时间等因素对提 取米糠多糖效果影响,并与热水直接浸提法进行比较。结果表明:微波辅助水浸提米糠多糖最佳工 艺条件为:液料比15∶1,pH 5,微波功率600 W,提取时间40 min,提取率可达2．78％;与热水直接 浸提法相比,微波辅助水浸提能显著缩短提取时间,提高提取率。     

二次通用旋转组合设计法优化米糠蛋白提取工艺

pH、提取温度和提取时间是影响米糠蛋白提取的3个最重要的因素。采用二次通用旋转组合设计试验方法，在控制反应条件保证米糠蛋白的功能性质不受影响的基础上，建立了pH、提取温度、提取时间与米糠蛋白提取工艺参数间关系的经验数学模型，得出了提取米糠蛋白的最佳工艺条件为料液比1：10,pH11，提取温度40℃，提取时间120min，在此条件下，米糠蛋白的提取率可以达到81．09％。     

超声波及匀浆技术在米糠多糖和米糠蛋白提取中的应用研究

研究了超声波和匀浆破碎技术在从米糠粕中提取米糠多糖和蛋白的应用，详细考察了超声波功率和时间以及匀浆转速和时间对米糠多糖和蛋白的提取率的影响．并结合已有的研究成果进行正交试验设计，确定米糠多糖和蛋白的提取条件为提取温度60℃，提取总时间3h，超声波处理时间20min，液料比1：15（w／v），匀浆预处理的转速为10000r／min，时间5min。     

巴西菇多糖提取方法研究

本文探讨了巴西菇多糖的提取工艺，分别作了热水提取和酶法提取的正交试验，并对多糖提取率进行了比较分析。结果显示．热水提取巴西菇多糖的最佳工艺参数是：提取温度110℃，提取时间1．5h，料液比1：25，其多糖最高提取率5．80％。而采用酶法提取巴西菇多糖的最佳工艺参数分别是：木瓜蛋白酶酶用量0．20％，酶解温度55℃，酶解时间2h，作用pH值6．5；纤维素酶酶用量O．15％，酶解温度45℃，酶解时间3h，作用pH值4．5；果胶酶酶用量O．20％，酶解温度40℃，酶解时间3h，作用pH值4．0。其中木瓜蛋白酶提取巴西菇多糖提取率最高，可达到15．08％。     

超声波辅助法提取米糠多糖的工艺研究

研究超声波辅助提取米糠多糖中温度、时间、加水量、超声功率对多糖提取率的影响,通过单因素实验和正交实验发现,温度对多糖提取率的影响最大,功率对多糖提取结果的影响最小,超声波辅助提取米糠多糖的最佳工艺条件为:温度80℃、时间70min、加水量20倍、功率200W,此时米糠多糖的提取率为1.75%,比热水法的提高了66.98%。     

米糠多糖提取与纯化工艺研究

采用微波辅助技术从米糠中提取米糠多糖,通过单因素和正交实验考察了料液比、微波功率、水提时间、水提温度对米糠多糖得率的影响,得出了米糠多糖最佳提取条件;并通过微滤膜技术进一步纯化米糠多糖。结果表明:米糠多糖的最佳提取条件为料液比1∶12、微波功率500 W、水提时间90min、水提温度60℃。经过微滤膜纯化后,米糠多糖纯度为83.3%。     

枸杞多糖酶法提取及其对油脂的抗氧化性能研究

研究了提取枸杞多糖的酶种类以及pH值、提取温度、提取时间、酶添加量对枸杞多糖得率的影响，并且确定了最佳提取条件。采用烘箱自氧化法研究了枸杞多糖对油脂的抗氧化性能。实验结果表明，混合酶提取效果最好，最佳提取条件：pH5．0，提取温度50℃，添加0．1％的酶，提取2h；枸杞多糖对油脂有一定的抗氧化性能，而且对动物油的抗氧化性优于植物油。     

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