超高效液相色谱-串联质谱法测定大豆中异黄酮素含量

目的 以染料木黄酮、大豆苷元和黄豆黄素的含量为指标,建立超高效液相色谱-串联质谱测定大豆中异黄酮素总量的方法。方法 样品用乙醇-水(3+1,V/V)提取,经过β-葡萄糖苷酶水解后,用Acquity UPLC?BEH C18柱(2.1 mm×100 mm, 1.7μm)分离,以甲醇和0.1%甲酸溶液(含5 mmol/L乙酸铵)作为流动相进行梯度洗脱,电喷雾负离子模式(ESI-)电离,多反应监测模式进行检测。结果 染料木黄酮、大豆苷元在5.0～500μg/L范围内线性关系良好(r>0.995),方法的检出限分别为2.7、4.0 mg/kg,在300.0、600.0、1 200 mg/kg添加水平的平均回收率为89.4%～102.2%,相对标准偏差(n=6)为1.5%～4.6%;黄豆黄素在0.5～50.0μg/L范围内线性关系良好(r>0.995),方法的检出限为0.6 mg/kg,在30.0、60.0、120.0 mg/kg添加水平的平均回收率为85.7%～104.0%,相对标准偏差(n=6)为1.3%～2.8%。结论 该方法简单、灵敏、准确可靠,适用于大豆中异黄酮素含量的测定...     

HPLC法测定食品中金雀异黄素

为保证保健食品的质量,建立了测定食品中金雀异黄素的HPLC方法.试样以乙醚脱脂,甲醇+水(80+20,体积分数)超声提取30 min,定容后过0.45 μm滤膜,上250.0 mm×4.6 mm、粒径10 μm的C18柱,甲醇+醋酸铵(0.050 mol/L,pH 4.6)作流动相,二极管阵列检测器测定.染料木苷、黄豆苷、黄豆苷元对测定不产生干扰.方法回收率85%～110%,相对标准偏差2%～8%,最低检出限为0.10 μg.本方法适用于保健食品中金雀异黄素的测定.     

北京地区不同大豆品种异黄酮含量比较研究

异黄酮是大豆生长过程中自然产生的化学物质,被认为可以治疗和预防一些人类依赖激素的疾病.为比较北京地区生态条件下大豆品种间异黄酮含量的差异性,对53个品种种子中3种异黄酮(大豆苷元、染料木素和黄豆黄素)进行测定和分析.结果表明,品种间异黄酮含量存在较大多样性,大豆苷元为39.21～2 363.65 μg/g,染料木素为77.35～1 149.50 μg/g,黄豆黄素为0.0～51.30μg/g,3种异黄酮总量为146.73～2 845.60 μg/g.来自山西和山东品种的异黄酮含量显著高于其他地区的品种.异黄酮总量分别与大豆苷元和染料木素呈极显著正相关,而大豆苷元和染料木素之间没有互作.因此,可以利用高含量大豆苷元或染料木素材料选育高异黄酮品种.     

热处理与大豆异黄酮苷元的转化分析

目的研究不同加热处理后大豆异黄酮苷元的含量和比例变化情况。方法大豆样品经烘箱50、100和150℃烘干,微波加热5min和炒熟等热处理后,由80%乙醇溶液超声提取,经高效液相色谱SB-C18柱(4.6mm×250mm,5μm)分离,0.2%冰乙酸+甲醇溶液梯度洗脱,紫外检测器260nm检测苷元和β-葡萄糖苷型大豆异黄酮含量。结果黄豆中检测出黄豆苷元、染料木素2种苷元和黄豆苷、黄豆黄苷2种β-葡萄糖苷。随烘箱加热温度升高,黄豆苷元含量增加1～5倍;染料木素增加3～15倍。炒豆中苷元和β-葡萄糖苷增加量最多。微波加热与50℃烘箱加热结果基本相同。青豆、黑豆与黄豆结果相近。结论加热使豆粉中部分糖苷型大豆异黄酮分解转化为苷元,活性成分增多,营养保健价值提高。     

霉菌型豆豉和纳豆中异黄酮含量的比较研究

目的:比较纳豆和豆豉中异黄酮含量的组成变化。方法:利用超声波提取,采用高效液相色谱法测定,色谱柱填料为Hypersil ODS2(4.6 mm×250 mm,5μm),流动相为甲醇(A)-水(B)进行梯度洗脱,检测波长为255 nm。结果:豆豉与纳豆相比较,豆豉中大豆苷、黄豆黄苷、染料木苷、大豆甙元、黄豆黄素、染料木素的含量分别为11,未检出,25,320,65,380μg/g;纳豆中中大豆苷、黄豆黄苷、染料木苷、大豆甙元、黄豆黄素、染料木素的含量分别为330,73,410,12,3.3,28μg/g。结论:豆豉中甙元的含量高,纳豆中糖苷的含量高。     

偏钒酸钠促进大豆芽异黄酮类物质黄豆苷元和染料木黄酮合成的研究

目的:分析比较偏钒酸钠对大豆芽合成异黄酮类物质-黄豆苷元和染料木黄酮的影响;方法:将大豆种子在不同浓度的偏钒酸钠水溶液(0、200、400、600、800、1000、1200、1400、1600mg/LNaVO3)于28℃萌发6d,第6d收获富钒大豆芽,洗净烘干至恒重,用95%乙醇提取大豆芽中的异黄酮类物质-黄豆苷元和染料木黄素,黄豆苷元和染料木黄素含量由高效液相色谱法测定;结果:分析测定结果表明,当大豆种子在浓度为200～600mg/L偏钒酸钠溶液中于28℃萌发6d,收获的大豆芽中的异黄酮类物质黄豆苷元和染料木黄酮的含量高于同等条件下其他浓度偏钒酸钠萌发液中萌发的大豆芽;结论:综合大豆芽的生长情况及大豆芽中异黄酮类物质-黄豆苷元和染料木黄酮含量等因素,在本实验条件下,萌发富钒大豆芽的适宜偏钒酸钠酸浓度为200～600mg/L,适宜的培育时间为96～120h,适宜温度为28℃。     

豆浆热处理过程中3种大豆异黄酮苷原的热降解比较

将大豆加工成豆浆并分别用95、121和140℃处理不同时间，以高效液相色谱（HPLC）法检测其中的3种大豆异黄酮皆原，染料木黄酮（genistein）、黄豆苷原（daidzein）和大豆黄素（glycitein）的含量变化，与原粒大豆、生豆浆进行比较。结果发现，染料木黄酮、黄豆苷原和大豆黄素的热稳定性存在较大差异，在95℃下，染料木黄酮在60min的处理时间内稳定，而黄豆苷原和大豆黄素的T（loss0.5）值（损失50％含量的时间）分别为1442s和453s，表明95℃下3种大豆异黄酮的热稳定性表现为：染料木黄酮〉黄豆苷原〉大豆黄素。而在121℃和140℃的处理条件下，3种大豆异黄酮苷原均随着处理时间的延长而出现不同的热降解，黄豆苷原、大豆黄素和染料木黄酮在121℃的T（loss0.5）值分别为26．36、37．88和1015s，而在140℃下，黄豆苷原、大豆黄素和染料木黄酮的T（loss0.5）值则分别缩短为6．94、8．47和369s，结果表明在121℃和140℃下，3种大豆异黄酮的热稳定性表现为：染料木黄酮〉大豆黄素〉黄豆苷原。     

酶法提高豆浆中大豆异黄酮苷元浓度的工艺研究

试验利用黑曲霉β-葡萄糖苷酶处对豆浆进行水解处理,将结合型大豆异黄酮糖苷转化为游离型苷元。选大豆为原料,以单因素实验为基础,考察加酶量、反应时间、反应温度三个因素对豆浆中大豆异黄酮糖苷水解的影响;根据Box-Behnken实验设计原理,选取不同加酶量、反应时间、反应温度3因素3水平进行中心组合实验,建立豆浆中大豆异黄酮苷元含量的多项式回归预测模型,确定了最佳工艺参数。结果表明,最佳水解工艺条件为:加酶量0.028 U/5 mL,反应时间1.64 h,反应温度53.82℃,在此条件下制得豆浆大豆异黄酮苷元含量明显提高。测得大豆苷元(De)、黄豆黄素(Gle)、染料木素(Ge)的浓度分别为39.434±1.410μg/m L、4.626±0.462μg/m L、45.851±2.098μg/m L。而大豆苷元(De、)黄豆黄素(Gle)、染料木素(Ge)浓度的响应面预测值分别为40.905μg/m L、4.263μg/m L、48.441μg/m L,测定值与模拟值接近。优化后的工艺条件合理、可行,能明显提高豆浆中大豆异黄酮苷元的含量。     

浙江大豆核心亲本蛋白质和异黄酮含量的分析

蛋白质和异黄酮是大豆的2个重要品质性状,但是这两类物质之间的关系在浙江省内却少有研究。本研究选取了种植于浙江省的196份来自不同地区(94份来自黄淮海地区,102份来自南方地区)的大豆核心亲本作为研究对象,测定其蛋白质和异黄酮组分的含量,并对蛋白质与异黄酮各组分之间进行相关性分析。结果表明,蛋白质含量和异黄酮总含量的范围分别为352~501 g/kg和254.1~6 068.9 mg/kg;丙二酰染料木苷、丙二酰黄豆苷、黄豆苷和染料木苷这4种成分的平均含量最高,分别为966.4、667.2、206.0、229.3 mg/kg。我国南方地区大豆种质的蛋白质含量显著高于黄淮海地区,但是两个地区异黄酮总含量则无显著差异。对于蛋白质与异黄酮成分的相关性分析,发现蛋白质与染料木苷和黄豆黄素苷元之间均存在负相关性。在参试材料中,响水黑豆和72-424这2个品种具有高蛋白、高异黄酮性状。大豆籽粒的蛋白质与异黄酮性状能够同时进行改良,通过筛选和育种改良大豆品质,可以获得高蛋白、高异黄酮大豆。     

高效液相色谱法同时测定粮食中6种大豆异黄酮

目的建立高效液相色谱法(high performance liquid chromatography,HPLC)测定粮食中6种大豆异黄酮(大豆苷、大豆黄苷、染料木苷、大豆素、大豆黄素和染料木素)含量的分析方法。方法准确称取一定量粉碎混匀后的样品,经80%甲醇提取后取上清液,过0.22μm有机相滤膜上机。采用Thermo Syncronis C18柱(250 mm×4.6 mm,5μm),以0.5%甲酸水溶液(A)、乙腈(B)和甲醇(C)作为流动相进行梯度洗脱,流速0.8m L/min,柱温为35℃,于紫外检测器波长260 nm处检测,大豆异黄酮各组分含量以外标法进行定量。结果本方法在30 min内完成6种大豆异黄酮的分离分析,大豆异黄酮各组分浓度在0.2~50μg/mL范围内呈良好的线性关系(r0.999),平均加标回收率为96.9%~107.8%,相对标准偏差(relative standard deviation,RSD)为0.6%~5.0%,检出限为0.03~0.1μg/mL,定量限为0.1~0.3μg/mL。结论建立的方法具有较高的灵敏度和重复性,能满足不同粮食种类中大豆异黄酮含量测定。     

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