高效液相色谱测定水解大豆中异黄酮方法研究

该研究建立大豆提取物中大豆异黄酮高效液相色谱测定方法,通过正交实验确立糖苷型大豆异黄酮转化为游离型大豆异黄酮最佳酸水解工艺条件:盐酸浓度为2．0 mol/L,水解温度为80℃, 水解时间为1．5 h;采用ZorbaX 80A Extend-C18 4．6×150 mm 4 μm色谱柱,MeOH-1．8％冰乙酸水溶液(35:65,V／V)为流动相,MeOH 35％-50％梯度洗脱,流速1．0 ml/min,检测波长为260nm等色谱条件下测定甙元含量,并通过换算因子计算大豆异黄酮含量。     

HPLC法检测黑豆乙醇提取物中活性成分的含量

采用高效液相色谱技术（HPLC），建立快速、有效、能同时分析检测黑豆乙醇提取物中大豆苷、苷元、木苷、木素含量的检测方法。结果：在一定条件下流动相及其比例对各组分的分离测定有较大的影响，我们所确定的色谱条件为：固定相：C18柱，流动相：甲醇：水：乙酸为42：57：1，检测波长为260nm；标准对照品的浓度与吸收峰面积均有较好的线性关系，r〉0．99，各组分间分离度大于1．5；测得的黑豆乙醇提取物中大豆苷、染料木苷、大豆苷元、染料木素的平均含量（％）分别为：0．341、0．386、0．0929、0．0265。RSD（％）分别为3．49、5．12、10．0、4．94。HPLC法可同时检测黑豆提取物异黄酮中大豆苷、染料木苷、大豆苷元、染料木素的含量，而且方法简单、快速、精密度高、重现性好。     

HPLC法测定大豆提取物中大豆异黄酮含量的研究

主要建立了HPLC法测定大豆提取物中大豆异黄酮含量的方法。通过实验确定了HPLC法测定大豆提取物中大豆异黄酮的最佳条件是：采用Waters Symmetry5μmC18,250mm×4．6mm色谱柱;流速：1．0mL／min;波长260nm;柱温：35℃;流动相A为含0．1％（v/v）乙酸的乙腈溶液,流动相B为含0．1％（v／v）乙酸的超纯水溶液,流动相梯度：18％-35％N乙腈溶液。该方法灵敏度高、重现性好,回收率达98％,变异系数小于3％,为研究大豆异黄酮其它产品打下了良好的基础,操作方法简单,易于掌握。     

超声辅助提取大豆异黄酮的研究

比较了醇提法与超声及超声加搅拌辅助提取大豆异黄酮的效果。正交试验结果显示，当超声频率为25kHz、超声功率为160W、乙醇浓度为50％、料液比为1：6、60℃超声处理60min时，大豆异黄酮的得率和含量分别可达4．23mg／g和2．74％，与醇提法相比分别提高了3．93％和7．87％；采用相同条件下的超声加搅拌(300r／min)处理，大豆异黄酮得率可达4．36mg／g，与单纯超声辅助提取法相比提高了3．07％，但其含量有所下降。超声辅助提取法对大豆异黄酮的抗氧化活性无影响。     

高效液相色谱法测定大豆异黄酮含量的研究

采用高效液相色谱 (HPLC)法对大豆异黄酮产品进行含量测定 ,是快捷、准确检测大豆异黄酮含量的方法。结果显示 ,确定标准样品Daidzin和Genistin作为检测大豆异黄酮的主要成分是有实验根据的 ,这两种成分占大豆异黄酮总量 95 %以上 ,可以代表总体样本。最佳的色谱条件为 :色谱柱VP -ODS(Φ4 .6mm× 15 0mm) ,流动相VMeOH:VHAc:VH2 O(4 0∶0 .5∶6 0 ) ,流速 1.5mL/min ,柱温 4 0℃ ,最适检测波长 2 5 4nm。     

米曲霉产大豆异黄酮糖苷酶发酵条件的研究

通过单因素实验和正交实验，探讨米曲霉O3产大豆异黄酮糖苷酶的最佳条件。结果表明：在培养基组分为玉米芯3％、豆饼粉0．2％、KH2PO40．4％、CaCI20．04％、MgSO4-7H2O 0．04％，自然pH，接种量为10％，培养温度为30℃，60h的条件下，米曲霉O3菌株的产酶活性较高，可达388．572U／mL。     

大豆异黄酮酸水解工艺的研究探讨

通过正交实验确立了糖苷型大豆异黄酮转化为游离型大豆异黄酮的最佳酸水解工艺条件：盐酸甲醇溶液的浓度为2mol／L，水解温度为80℃，水解时间为60min。水解前样品中大豆异黄酮的含量为D：13．86％、G：23．48％、De：0．22％、Ge：0．02％，水解后样品中大豆异黄酮的含量为D：nd(未检出)、G：nd(未检出)、De：14．01％、Ge：23．45％，水解充分。     

高效液相色谱法测定大豆中异黄酮的含量

用高效液相色谱法测定了大豆中六种异黄酮成分,同时比较了不同浓度乙醇制备样品对含量测定的影响。结果显示大豆中极性异黄酮含量高,低极性异黄酮甙元含量低。测定大豆中异黄酮含量的乙醇浓度最好控制在60％-80％。色谱柱采用日本岛津公司的Shim-Pack CLC ODS柱(150×6．0mmID5μm),流动相为MeOHHACH2O（303.566.5),流速为0-8．5min时1．0ml／min,5．8-47min时1．5ml／min,柱温为50℃,检测波长为254。     

腐乳中的大豆异黄酮高效液相色谱分析

采用polaris C18(2.0mm×100mm,3μ),水(含0.3%H3PO4)、乙腈为流动相,梯度洗脱,流速0.30mL/min,柱温50%,测定波长(λ)260nm,分析腐乳中大豆异黄酮.在选定色谱条件下大豆异黄酮的线性范围为0.2 mg/L～40mg/L,样品加样回收率为90.0%～95.2%,相对标准偏差为0.90%～2.45%.本方法精密度好,结果可靠,适合于腐乳中大豆异黄酮的定量分析.     

大豆粕功能性成分提取条件的研究

综述了大豆中各种活性成分的研究进展，并在综合利用的基础上对从大豆粕中提取分离大豆异黄酮和大豆皂甙的工艺条件进行了探讨。实验结果表明：以水为提取剂，料液比(质量浓度)1：10，在60～70℃下，浸提2～3h，异黄酮的回收率可达85％以上，蛋白质的提取率为2．55～3．07g／dL；采用95％过20目筛的细度即可得到满意的效果，异黄酮回收率可达90％，蛋白质收率2．95g／dL；异黄酮在大孔树脂和AB-8树脂吸附后，以质量分数20％～60％的乙醇为洗脱液，AB-8树脂的得率比大孔树脂高14.67％；收集水洗脱液可制取大豆低聚糖。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.