人参皂苷Rg5的提取制备工艺研究

在柠檬酸作用下,以人参须根粉为原料直接提取制备人参皂苷Rg5,以达到简化试验步骤、节省时间、绿色制备的目的。通过单因素试验探索提取温度、酸浓度和固液比对人参皂苷Rg5得率的影响,响应曲面分析法对人参皂苷Rg5的提取制备工艺进行优化,通过高效液相色谱法(HPLC)对人参皂苷Rg5进行定量分析。试验结果表明,人参皂苷Rg5的加样回收率为99.73%~101.72%,平均加样回收率为100.37%;人参皂苷Rg5以在溶液中48 h内稳定性良好;在柠檬酸的催化下,水-正丁醇=8∶2(体积比)的混合溶剂为提取剂,提取温度为112℃,酸浓度为0.14 mol/L,固液比为1∶28(g/m L),人参皂苷Rg5得率为1.54%。     

响应曲面法优化人参须根粉中人参皂苷Rg5的制备工艺

旨在建立以磷酸为催化剂,从人参须根粉中直接提取制备稀有人参皂苷Rg5的方法。通过单因素试验和响应面分析对其制备工艺进行优化,并利用HPLC法对人参提取物中的人参皂苷Rg5进行定量分析。试验结果表明:加样回收率在98.23%~101.82%,平均回收率为100.67%,RSD为1.21%;最佳提取工艺为以水-95%乙醇=6∶4的混合溶液为提取剂,固液比为1∶40(g/mL),提取液酸浓度0.15 mol/L,提取温度100℃,提取时间6.5 h,人参皂苷Rg5的最高得率为2.17%。     

响应曲面法优化微波辅助提取人参须根粉中人参皂苷Rg5的工艺研究

为直接提取制备人参须根粉中的人参皂苷Rg5,实现一步法直接制备人参皂苷Rg5,以解决提取时间长、得率低的问题。在单因素实验基础上,采用响应曲面法优化微波辅助提取制备人参皂苷Rg5的工艺。研究了提取功率、提取液酸浓度、固液比和提取时间4个因素及其相互作用对人参皂苷Rg5得率的影响。利用高效液相色谱法对人参皂苷Rg5进行定量分析。实验结果表明,对人参皂苷Rg5得率的影响次序为提取液酸浓度提取功率固液比提取时间;人参皂苷Rg5的最佳提取工艺条件为:提取功率500 W,提取液酸浓度0.12 mol·L-1,固液比1∶42(g·m L-1),提取时间9 min,人参皂苷Rg5得率可达到3.14%,表明该方法可有效提取人参须根粉中人参皂苷Rg5。     

天然柠檬汁催化人参须根粉制备20（S,R）-Rg3和Rg5工艺研究

利用多功能改进型索氏提取器,研究天然柠檬汁催化人参须根粉转化制备稀有人参皂苷20（S,R）-Rg3、Rg5的方法。以乙醇浓度、提取时间和提取筒温度为影响因素,人参皂苷20（S,R）-Rg3、Rg5总得率为指标进行正交试验,对提取工艺进行优化。结果表明,最佳提取条件为提取时间4 h、乙醇浓度30%、提取筒温度75℃。在此条件下,人参皂苷20（S,R）-Rg3、Rg5总得率为3.68%。多功能改进型索氏提取器的梯度提取制备工艺可显著缩短人参皂苷的提取时间,简化提取过程,并有效提高人参皂苷20（S,R）-Rg3、Rg5的总得率。     

人参果浆中人参皂苷Re的提取和生物转化

为了充分利用人参资源,本文以加工厂废弃的人参果浆为原料,分析人参果浆中的皂苷含量和组成,并从中提取人参皂苷Re,以人参皂苷Re为底物,采用人参自身酶为催化剂,生物转化得到人参皂苷Rg2组。结果表明,人参加工厂废弃果浆的干品中,皂苷含量为6.21%(W/W),其中人参皂苷Re的含量为55.1%(W/W)。从果浆的干品中提取纯化得到了人参皂苷Re,得率为2.4%(W/W)。人参皂苷Re生物转化制备得到人参皂苷Rg2组,得率为65%(W/W)。经高效液相色谱(HPLC)及超高效液相-四级杆飞行时间串联质谱(UPLC-Q-TOF-MS)分析得出,人参皂苷Rg2组由20(S)-Rg2、20(R)-Rg2、Rg4和Rg6组成,本论文为人参加工厂废弃果浆的综合利用提供了理论依据。     

人参-虫草双向固体发酵过程中人参皂苷含量变化研究

研究人参-冬虫夏草双向固体发酵过程中主要人参皂苷的组成和含量变化,为发酵产物的质量控制和开发利用提供理论依据。采用高效液相色谱-质谱联用（HPLC-MS）技术对发酵过程及产物中人参皂苷进行定性定量分析。结果表明,人参-虫草双向固体发酵产物中共鉴定出11种皂苷。其在200～1 500 ng/mL范围内线性关系良好（R2＞0.999）,加标回收率范围为95.13%～105.04%,相对标准偏差（RSD）为0.85%～2.36%,精密度、稳定性、重复性试验结果的RSD均＜2.6%,表明该检测方法精密度、准确度、稳定性及重复性良好。人参-虫草双向固体发酵过程中人参皂苷Rg1、Re、Rb1含量明显降低,人参皂苷Rh1、Rg2、Rd、Rg3、F2含量明显增加。     

HPLC法测定复方保健酒中人参皂苷和西红花苷的含量

采用高效液相色谱仪建立测定复方保健酒中人参皂苷Rg1、人参皂苷Rb1、人参皂苷Rb2、人参皂苷Rc、西红花苷I、西红花苷II含量的方法。结果表明,最佳测定条件为采用Agilent SB-Aq色谱柱（4.6 mm×250 mm,5 μm）,以乙腈-水为流动相梯度洗脱,流速1.0 mL/min,柱温30 ℃,人参皂苷的检测波长203 nm,西红花苷的检测波长为440 nm,进样量10 μL。人参皂苷Rg1、人参皂苷Rb1、人参皂苷Rb2、人参皂苷Rc、西红花苷I、西红花苷II在各自浓度范围内线性关系良好（R≥0.999 9）,平均加标回收率97.83%～101.72%,精密度试验结果相对标准偏差（RSD）0.43%～1.85%。实验结果表明该方法操作简单,精密度和准确度高,重复性好,可用于复方保健酒中人参皂苷和西红花苷含量测定。     

基于UPLC-QAMS同时测定参鹿酒中7种人参皂苷含量

该研究旨在建立超高效液相色谱(UPLC)-一测多评(QAMS)法同时测定参鹿酒中7种人参皂苷(Rg1、Re、Rf、Rb1、Rc、Rb2及Rd)的含量。首先采用UPLC测定参鹿酒中7种人参皂苷含量，并进行方法学考察。然后以人参皂苷Rg1为参照物，计算其余6种人参皂苷的相对校正因子及含量，并考察QAMS法的耐用性。最后与外标法相比，验证QAMS的可行性。结果表明，7种人参皂苷在各自范围内线性关系良好(R2>0.999)，精密度、重复性及稳定性试验结果的相对标准偏差(RSD)均<3%，加样回收率为100.13%～101.73%。6种人参皂苷的相对校正因子的RSD值均<5%，重现性良好。采用相对校正因子计算得到的13批参鹿酒样品中7种人参皂苷的含量与外标法实测值的相对误差(RE)均<5%，说明所建立的UPLC-QAMS法可有效、快速的评价参鹿酒的质量。     

超高效液相色谱法检测6种人参皂苷含量

采用超声提取药食同源植物(人参、西洋参、三七)中原人参三醇皂苷(Rg1、Re、Rf)和原人参二醇皂苷(Rb1、Rc、Rd),建立了超高效液相色谱(UPLC)检测方法。以50%甲醇溶液为提取剂,料液比1∶80(g∶m L),超声时间30 min。采用乙腈和0.05%磷酸水为流动相,梯度洗脱,检测波长为203 nm。该方法在质量浓度5~1 000μg/m L范围内线性良好,6种皂苷的最低检出限在22.5~51.0 mg/kg之间,平均回收率98.1%~105.5%。该方法准确、灵敏度高、重现性好、省时快捷,适合日常、大批量样品的检测。用此方法测定市售人参、西洋参及三七样品,结果表明3类样品中原人参二醇类皂苷含量高于三醇类皂苷,三七样品中Rg1的含量比人参和西洋参高,西洋参中Re含量高于人参和三七样品,而Rf仅在人参样品中检测到。     

纤维素酶-乙醇结合法提取人参总皂苷提取工艺的研究

利用纤维素酶-乙醇结合法提取人参总皂苷。通过单因素试验考察提取体系pH、纤维素酶添加量、乙醇浓度、酶解温度、料液比、提取时间和提取次数对人参总皂苷提取率的影响。利用正交试验设计得到最优提取条件:提取温度为50℃、提取次数为2次,pH为5.0、乙醇浓度为40%,酶添加量为1.5%、固液比为1∶12、提取时间为2h。在最优条件下,纤维素酶-乙醇结合法提取人参总皂苷的得率为2.73%。对比试验证明,纤维素酶-乙醇结合法提取的人参总皂苷提取率高于参考条件下回流提取法和浸提法。结果证明纤维素酶-乙醇结合法可以得到较高的人参总皂苷提取率。     

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