海金沙组培苗水溶性多糖和总黄酮综合提取工艺优化

研究了热水浸提海金沙组培苗水溶性多糖和总黄酮综合提取工艺的优化。在单因素实验的基础上,选定提取温度、提取时间及料液比进行3因素3水平中心组合实验,建立水溶性多糖和总黄酮的总得率二次回归方程,通过响应面分析得到较优的综合提取工艺参数为提取时间2.1h、提取温度80.6℃和料液比1∶26.2（g/mL）。在此优化条件下得到海金沙组培苗中水溶性多糖提取得率为13.241%,总黄酮得率为3.211%,二者总得率为16.452%。     

花菇多糖的提取工艺优化

采用中心组合实验对花菇水溶性和碱溶性多糖的提取工艺进行了优化。实验结果表明：花菇水溶性多糖的最佳提取条件为提取温度94．34℃，提取时间为3．5h，料液比为1：61．88，在此条件下花菇中水溶性多糖得率最高达到6．78％；花菇碱溶性多糖的最佳提取条件为碱NaOH浓度为1．816mol／L，提取时间为1．7h，料液比为1：60，此时花菇中碱溶性多糖得率最高可达到3．95％。     

挤压法提取竹叶多糖和黄酮的研究

采用挤压法提取竹叶中水溶性多糖和总黄酮,研究其对多糖相对分子质量的影响,并与传统方法作比较。试验结果表明,用挤压法提取的竹叶水溶性多糖和总黄酮质量浓度分别达2.969、1.266mg/mL。与传统方法相比,多糖相对分子质量几乎没有变化,说明采用挤压法提取水溶性多糖和总黄酮是可行的,具有提取时间短、迅速的特点。     

油菜蜂花粉多糖和黄酮的提取研究

对油菜蜂花粉多糖和总黄酮的提职工艺进行了研究.通过单因素和正交试验确定了油菜蜂花粉多糖和总黄酮的最佳提取工艺条件.结果表明:在温度为90℃、pH值为5、料水比1:8(m/V)时提取1.0h,油菜蜂花粉多糖得率为25.12%,提取率为81.55%;选用95%乙醇作为溶剂,料液比1:7(m/V),在70℃水浴中提取1.5 h,油菜蜂花粉总黄酮得率为3.32%,提取率为94.80%.本研究采用方法工艺简单,提取率高.     

鸡腿菇菌柄多糖提取工艺的研究

将鸡腿菇子实体的菌柄与菌盖分离后,分别进行干燥,得鸡腿菇菌柄干粉。本文以鸡腿菇菌柄粉为材料,对菌柄水溶性多糖和碱溶性多糖的提取工艺条件进行了研究。通过单因素实验和响应面中心组合实验设计,确定了菌柄水溶性多糖的最佳提取工艺条件:料液比1∶40、温度81℃、时间2.5h、提取2次,水溶性多糖得率为12.65%,多糖含量为70.50%。通过单因素实验确定了菌柄碱溶性多糖的最佳提取工艺条件:料液比1∶10,4%NaOH溶液,80℃提取2h,提取2次,碱溶性多糖得率为20.14%,多糖含量为38.51%。     

固体发酵蜜环菌多糖提取工艺的研究

研究了从固体发酵蜜环菌菌丝体中提取水溶性多糖的工艺。通过比较,证明了冷冻能提高多糖的提取效率;通过单因素实验,确定水溶性多糖的提取工艺;正交试验进一步优化提取工艺：即浸提时间2．5h、浸提90℃、固液比1：5为最佳提取条件。     

草珊瑚水溶性粗多糖提取及抗氧化性能研究

研究了草珊瑚水溶性粗多糖的提取工艺及抗氧化性能。采用单因素试验和L9(34)正交试验设计,考察了提取温度、时间、料液比、提取次数等因素对提取率的影响,并采用水杨酸法考察草珊瑚粗多糖抗氧化性能。结果表明,温度是影响粗多糖提取的重要因素。优化工艺条件为:提取温度95℃、提取时间4h、料液比1:20、提取三次。抗氧化实验表明草珊瑚粗多糖有较好的抗氧化活性。     

洋葱水溶性多糖的提取工艺研究

通过正交试验设计以期获得洋葱中水溶性多糖的最佳提取工艺.以新鲜洋葱为原料,采用水提法提取洋葱水溶性多糖,以提取温度、提取时间、料液比扣提取次数为考查因素,比较各因素对洋葱水溶性多糖提取率的影响.结果表明:水提法提取洋葱水溶性多糖的最佳工艺参数为提取时间3.0h,提取温度80℃,液料比1∶12(m∶V),提取次数3次.在该提取条件下洋葱水溶性多糖提取率可达到3.697％.     

中国板党中硒多糖提取分离技术研究

本研究以富含硒元素的恩施药材--中国板党为原料,对党参含硒多糖的分离提取技术进行了初步研究。实验采用水浸提、乙醇醇析提取、Sevage脱蛋白、干燥等方法研究中国板党含硒多糖的提取工艺,并用蒽酮比色法和原子吸收法对多糖含量、硒含量分别进行了测验。结果表明:板党水溶性含硒多糖最佳提取条件为:提取2次、加料液比为1:20、提取时间2h、提取温度为95℃。水溶性多糖含量为5.50%,多糖硒的含量为0.259μg/g。     

小花八角多糖提取优化工艺及自由基清除作用研究

小花八角多糖是一种水溶性天然多糖,本文研究了小花八角多糖的提取工艺及其清除自由基的能力。通过单因素实验和正交实验,结果表明,小花八角水溶性多糖的最佳提取工艺条件为:提取温度75℃、料液比1∶14、提取时间2h、超声波功率300W,水溶性小花八角多糖的得率为0.83%。进行清除自由基活性研究,结果显示,小花八角多糖具有清除自由基的作用。     

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.