大孔树脂分离纯化花生壳水溶性膳食纤维工艺条件研究

选取8种大孔吸附树脂进行静态吸附性能研究,筛选出最有效D101树脂分离纯化花生壳水溶性膳食纤维。通过动态吸附性能研究,确定应用D101树脂分离纯化花生壳水溶性膳食纤维优化工艺条件;在上样流速2 ml/min、上样液质量浓度为1 mg/mL² mg/mL、上样液pH为10左右条件下吸附较强;在洗脱剂乙醇体积分数为70%、洗脱液流速为1 ml/min洗脱时洗脱效果最好。经紫外光谱扫描及SDF纯化物纯度测定结果显示,经纯化后花生壳水溶性膳食纤维纯度较高,可达96.4%;且蛋白含量较少,仅为0.23%。     

爬山虎籽中原花青素提取纯化工艺及含量测定

设计正交试验探讨从爬山虎籽中提取纯化原花青素的工艺。结果表明：乙醇浸提的最佳浸提工艺为乙醇体积分数60%、提取温度70℃、提取时间90min、料液比1:10(g/mL),在最佳浸提工艺条件下,从爬山虎籽中提取原花青素得率1.407%;大孔吸附树脂分离纯化原花青素的结果表明,AB-8 树脂适合精制爬山虎籽中原花青素,柱分离条件为上样液质量浓度为4mg/mL、洗脱液为体积分数30% 的乙醇溶液、洗脱流速2.0BV/h。精制后的原花青素经HPLC 检测其纯度达88.0%。     

大孔吸附树脂及高速逆流色谱分离纯化石榴皮中安石榴苷

为了从石榴皮中制备高纯度安石榴苷,采用大孔吸附树脂和高速逆流色谱分离纯化石榴皮中安石榴苷。响应面分析结果显示,最优纯化条件为:吸附液浓度1.0 mg/mL,吸附时间50 min,吸附流速1.0 mL/min,在此条件下,吸附率达到86.16%,各因素对吸附率影响顺序为吸附流速吸附液浓度吸附时间;洗脱乙醇体积分数40%,洗脱时间150 min,洗脱流速1.0 mL/min,在此条件下,洗脱率达到71.89%,各因素对洗脱率影响顺序为乙醇体积分数洗脱流速洗脱时间;以正丁醇-三氟乙酸-水(100︰1︰100)为溶剂体系,上相为流动相,下相为固定相,流速1.5 mL/min,转速800 r/min,可以得到纯度为90%以上的安石榴苷纯化产物。该工艺可为石榴皮综合利用提供技术参考。     

高速逆流色谱分离纯化紫甘蓝花色苷

优化出超声波溶剂辅助法提取紫甘蓝花色苷的最佳工艺条件,并用高速逆流色谱法对其进行分离纯化,建立HSC-CC分离制备紫甘蓝花色苷类化合物的方法。采用正交试验优化超声波溶剂辅助提取紫甘蓝花色苷的工艺条件,再高速逆流色谱对其进行分离纯化。结果表明,超声波溶剂辅助提取紫甘蓝花色苷的最佳工艺条件为超声时间8min,超声辅助提取温度40℃,乙醇体积分数65%;HSCCC制备紫甘蓝花色苷类化合物的方法:溶剂系统为正丁醇-甲基叔丁基醚-乙腈-水-三氟乙酸(2:2:1:5:0.01,V/V/V/V),流速为2mL/min,主机转速设定为800r/min,紫外检测波长为254nm,在该条件下分离制备得到3种化合物。经HPLC检测其纯度分别为76.28%,45.46%,91.46%。用超声波溶剂辅助和高速逆流色谱能分离得到了高纯度的紫甘蓝花色苷,该法具有简便、快速的优点,为紫甘蓝花色苷的分离纯化提供了高效、稳定、可靠的方法。     

美味牛肝菌色素大孔树脂纯化工艺及抗氧化活性研究

目的:对美味牛肝菌色素进行大孔树脂纯化并研究其抗氧化性。方法:通过静态和动态试验考察了树脂类型、上样浓度、pH、上样流速、乙醇体积分数及洗脱流速对美味牛肝菌色素吸附—解吸性能的影响,确定最佳纯化工艺条件;并采用红外光谱及DPPH·、ABTS⁺·及·OH清除能力研究纯化后色素的特征结构和抗氧化性。结果:AB-8大孔树脂纯化美味牛肝菌色素效果最好,最佳纯化工艺条件为:样液质量浓度1.5 mg/mL、pH 2.0、上样流速3.0 mL/min、乙醇体积分数70%、解吸流速2.0 mL/min,该条件下,美味牛肝菌色素的纯化效率是269%。纯化后美味牛肝菌色素清除DPPH·、ABTS⁺·及·OH的IC₅₀值分别达到(0.081±0.001),(0.017±0.011),(0.119±0.001)mg/mL,其中清除·OH能力超过维生素C。结论:AB-8大孔树脂适用于美味牛肝菌色素的分离纯化,纯化后色素具有良好的抗氧化活性。     

淡竹叶多酚的提取纯化工艺优化、组分分析及体外抗氧化活性研究

目的 确定淡竹叶多酚提取纯化工艺,分析主要成分及体外抗氧化活性。方法 采用超声辅助提取淡竹叶多酚,通过响应面实验确定最佳提取条件。选取适合淡竹叶多酚纯化的大孔树脂,对纯化工艺参数进行优化。通过高效液相色谱-质谱法(high performance liquid chromatography-mass spectrometry, HPLC-MS)鉴定淡竹叶多酚的主要成分,并评价其体外抗氧化活性。结果 淡竹叶多酚的最佳提取工艺参数为:乙醇体积分数60%、超声功率500 W、料液比1:25 (g/mL)、超声时间24 min及超声温度59℃,该条件下淡竹叶多酚提取量为8.01 mg/g。淡竹叶多酚纯化工艺参数为:上样质量浓度6 mg/mL、pH 4、流速2 mL/min、解吸液为70%乙醇、解吸体积90 mL,纯化后的淡竹叶多酚纯度由12.86%提高到76.18%。通过HPLC-MS鉴定出16种酚类成分,且纯化后多酚有较高的抗氧化活性。结论 本研究得到了淡竹叶多酚提取纯化工艺,得到的多酚纯化物有明显的抗氧化活性。     

文冠果果壳皂甙的分离纯化及其抗氧化活性研究

采用AB-8大孔树脂对文冠果果壳皂甙进行纯化,研究了上样液质量浓度、乙醇体积分数、洗脱液流速和氢氧化钠质量分数对纯化效果的影响,进一步通过正交实验获得最佳工艺条件。实验结果表明,当上样液质量浓度为30 g/L,乙醇体积分数为70%,洗脱液流速为2.0 BV/h,氢氧化钠质量分数为0.20%时,纯化后的文冠果果壳皂甙纯度为67.81%,回收率为64.04%,并具有较强的抗氧化活性,能够有效清除DPPH自由基。     

大孔吸附树脂分离纯化薰衣草总黄酮

研究大孔树脂分离纯化伊犁薰衣草总黄酮的工艺条件与方法。结果表明:AB-8型大孔树脂对薰衣草总黄酮有较好的吸附和解吸效果,其最佳纯化工艺为:上样液pH6.0,粗提物溶液上样液总黄酮质量浓度0.5mg/mL,吸附流速2.00mL/min,用体积分数90%乙醇溶液以1.00mL/min的速率洗脱,解吸率94.53%,黄酮平均回收率109%。     

异丙醇-硫酸铵双水相体系分离甜玉米芯多糖

以甜玉米芯为原料,采用超声波辅助异丙醇-硫酸铵双水相体系分离甜玉米芯多糖。对影响分离甜玉米芯多糖的主要因素:异丙醇体积分数、硫酸铵用量和超声时间进行单因素研究,以多糖回收率作为响应值进行响应曲面设计分析,建立二次回归模型,优化分离条件。结果表明超声波辅助双水相体系分离甜玉米芯多糖的最佳工艺条件为:异丙醇体积分数36%、硫酸铵浓度0.25 g/m L、超声处理时间25 min。在最佳的优化条件下,甜玉米芯多糖回收率为98.98%。异丙醇-硫酸铵双水相体系分离甜玉米芯多糖具有较好的脱蛋白和脱色效果,可用于甜玉米芯多糖的分离纯化。     

AB-8大孔树脂纯化绿豆皮黄酮工艺优化及纯化前后抗氧化能力比较

采用AB-8大孔树脂初步分离纯化绿豆皮黄酮。分别对上样条件和洗脱条件进行优化,考察上样液质量浓度、上样液pH值、上样流速、以及洗脱剂体积分数、洗脱剂用量、洗脱流速对吸附解吸性能的影响,最终确定AB-8大孔树脂的分离纯化绿豆皮黄酮工艺为上样液质量浓度1.5?mg/mL、上样液pH5.0、上样流速1.0?mL/min;洗脱液乙醇体积分数70%、洗脱剂用量225?mL、洗脱流速2.0?mL/min,在此条件下分离纯化,绿豆皮黄酮纯度由27.95%提高到62.38%。经紫外-可见光谱扫描,出现黄酮类化合物特征峰带,经红外光谱扫描,光谱具备黄酮类物质特征官能团,验证了黄酮类物质的存在;利用扫描电镜对纯化前后黄酮类物质进行微观分析,得出被包裹的片状和粉粒状颗粒大部分被释放出来,这可能是导致纯化后黄酮类化合物纯度增高的原因。纯化后的绿豆皮黄酮与粗提物相比具有较高的抗氧化能力。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.