原料质量对提取食用葵花籽蛋白的影响

葵花籽粕是提取食用葵花籽蛋白的主要原料,研究和确定葵花籽粕的质量,是提取食用葵花籽蛋白产品一个十分重要的问题。本文根据葵花籽的质量、粕中含壳率、含油率和加工方式对提取食用葵花籽蛋白的影响,归纳出用葵花耔以及由它所制得的粕作食用植物蛋白原料的要求。     

葵花籽粕蛋白提取及分离纯化

以脱去绿原酸后的葵花籽粕作为原料,以蛋白质提取率为指标,通过单因素和正交试验确定碱溶酸沉法制备葵花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分离纯化。结果表明:葵花籽粕蛋白最优提取工艺为:料液比1:20,温度45℃,时间30 min,碱液pH12;在此条件下,葵花籽粕蛋白提取率为61.04%±0.24%,蛋白含量(以蛋白质含量计)为66.94%±0.24%;葵花籽粕蛋白质分离纯化最优工艺为:上样量3 mL、洗脱液流速0.4 mL/min,葵花籽粕蛋白含量(以蛋白质含量计)为93.20%±1.37%,比纯化前提高了39.23%。     

葵花籽粕蛋白制备及其功能性质分析

以提取绿原酸后的葵花籽粕为原料,在单因素试验的基础上,采用L9(34)正交优化试验确定葵花籽粕蛋白最佳制备工艺。采用蛋白层析仪分离纯化葵花籽粕蛋白,确定了纯化工艺,同时以大豆蛋白为对照,研究了葵花籽粕蛋白的溶解性、起泡性与起泡稳定性、乳化性与乳化稳定性、持水性、持油性等功能性质。结果表明,葵花籽粕粗蛋白最佳碱提工艺为料液比1∶25(g/m L)、温度40℃、时间30 min、碱液p H 12.0,提取率为61.04%±2.5%,蛋白质含量为66.94%±3.2%;分离纯化的工艺条件为上样量3.0 m L、洗脱液流速0.4 m L/min,纯化后蛋白质含量为93.20%±3.5%,纯度提高了26.36%±1.6%;葵花籽粕蛋白的等电点PI为4.2;葵花籽粕蛋白的溶解性,起泡性、起泡稳定性、乳化性、乳化稳定性均略高于大豆蛋白,持水性略低于大豆蛋白,持油性明显高于大豆蛋白。葵花籽粕蛋白有望作为食品工业的风味保持剂。     

葵花籽粕ACE抑制肽分离纯化及其性质研究

以葵花籽粕血管紧张素转化酶(ACE)抑制肽为原料,采用DA201-C大孔吸附树脂对其进行分离纯化,并对纯化后的葵花籽粕ACE抑制肽稳定性和活性进行了分析。结果表明:葵花籽粕ACE抑制肽最优纯化工艺为乙醇浓度70%、上样p H 5、上样流速2 BV/h、洗脱流速2 BV/h,在此条件下,得率为93.26%,纯化后的葵花籽粕ACE抑制肽的抑制率为92.23%±0.48%。葵花籽粕ACE抑制肽对热和金属离子均具有良好的稳定性,模拟体内消化实验显示其活性不受胃肠酶的影响。     

超声波预处理葵花籽粕蛋白制备抗氧化多肽的研究

以葵花籽粕蛋白粉为原料,利用超声波对其进行预处理,采用碱性蛋白酶和木瓜蛋白酶为酶制剂对葵花籽粕蛋白进行酶解,以抗氧化性为指标,通过单因素及响应面法对预处理条件进行优化,获取最佳预处理工艺。结果表明,葵花籽粕蛋白质的超声波最佳预处理工艺为:超声波时间25 min、超声波功率187.5 W、超声波温度40℃。在此条件下,葵花籽粕多肽对超氧阴离子自由基(O2-·)和羟基自由基(·OH)清除能力分别为67.11%和52.47%。     

葵花籽粕中多酚物质的提取工艺优化

本实验以葵花籽粕为原料,选取乙醇作为提取剂提取多酚,从温度、时间、乙醇体积分数、料液比、金属螯合剂六偏磷酸钠（SHMP）、乙二胺四乙酸二钠盐（EDTA）添加量六个方面分别进行研究,采用普通水浴的方法,对葵花籽粕多酚的提取率进行了考察,并在这六个单因素的基础上选取了4个主要因素进行正交试验设计。结果表明：浓度为0．4％的SHMP添加量能有效的提高葵花籽粕多酚的提取率,而浓度为0．4％的EDTA对葵花籽粕多酚的提取没有明显的影响;通过正交试验设计,由正交分析得出了提取葵花籽粕多酚的最佳提取：I：艺参数为：提取温度为50V、乙醇体积分数为50％、提取时间为80rain、料液比为1：25、SHMP添加量为0．4％。     

酶解-膜分离耦合制备葵花籽粕抗氧化肽的研究

副产品葵花籽粕富含优质蛋白质,利用葵花籽粕生产蛋白质多肽的研究甚少。为充分利用葵花籽粕中的蛋白质,试验研究了不同超滤膜截留的葵花籽粕蛋白多肽含量及其抗氧化性,并通过试验分析加酶量、酶膜耦合时间、泵转速等因素对葵花籽粕中的抗氧化肽产量及其活性的影响。试验结果表明:选择截留相对分子质量5 k Da的超滤膜进行酶膜耦合,制备葵花籽粕蛋白抗氧化肽,能够富集到抗氧化活性较强也较为纯净的葵花籽粕抗氧化肽,酶解-膜分离耦合试验确定的最佳工艺参数为:加酶量1.0 AU/g,泵转速120 r/min,酶解时间80 min。     

响应面法优化葵花籽粕蛋白酶解工艺研究

以葵花籽粕为原料,以酶解进程中酶解物氮收率和相对分子质量分布为评价指标,从碱性蛋白酶、中性蛋白酶、复合蛋白酶、风味蛋白酶和木瓜蛋白酶5种酶中筛选制备优质葵花籽多肽合适的蛋白酶。结果表明:葵花籽粕在碱性蛋白酶作用下,其氮收率最大,且酶解物相对分子质量分布较为理想。利用响应面法优化碱性蛋白酶酶解工艺,得出其最佳工艺条件为酶添加量3%,酶解时间2.10 h,p H10.0,料液比1∶16 (g/mL),在此条件下,葵花籽粕酶解物的氮收率77.11%。     

双酶酶解葵花籽粕蛋白制备抗氧化多肽的研究

本文以葵花籽粕蛋白粉为原料,获取双酶酶解葵花籽粕蛋白制备抗氧化活性多肽的最优工艺。分别采用碱性蛋白酶等七种蛋白酶对葵花籽粕蛋白进行酶解,以抗氧化性及水解度为指标对酶制剂进行筛选。以抗氧化性为指标,通过单因素及响应面法对酶解条件进行优化,获取最佳酶解工艺。结果表明,碱性蛋白酶和木瓜蛋白酶为最适酶制剂且最佳酶解工艺为:p H7.6、复合酶比例为2.5∶1、底物浓度2%、[E]/[S]为2%、酶解温度50℃、酶解时间200min,在此条件下,葵花籽粕多肽对O-2·和·OH清除能力分别为68.06%和50.12%。     

葵花籽粕中热变性蛋白粉制备工艺的研究

以当地油脂厂工业副产物葵花籽粕为原料,分离含有少量多酚类物质的可溶性蛋白粉。经测定,提取后的葵花籽蛋白含量为67.1%、白度为78%、脂肪为1‰、绿原酸为1.12%。由于蛋白质没有经过纯化含有部分多酚类物质,所得的产品具有抗氧化活性。分离出来的蛋白质具有很好的理化性质及功能性质,可作为活性物质应用于功能性食品研究与开发。     

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