正交设计优选婆婆针中聚炔苷的提取工艺研究

目的探讨提取婆婆针中聚炔苷的工艺。方法以聚炔苷含量为指标,采用正交设计优选最佳提取工艺。结果最佳提取工艺为70%乙醇,10倍量,回流提取1 h,提取3次。结论乙醇提取法优于水提取法。乙醇浓度对婆婆针中聚炔苷溶出量影响显著。     

乙醇处理对食荚豌豆保鲜效果的影响

研究了不同浓度的外源乙醇(1、2和3ml／kg)采后处理对食荚豌豆低温贮藏期间主要生理指标、腐烂和品质的影响c结果表明，1ml／kg的外源乙醇可有效抑制食荚豌豆贮藏期间的呼吸强度、乙烯释放和蒸腾失水，延缓了豆荚中叶绿素含量的下降及纤维素和木质素含量的上升，降低豆荚贮藏中腐烂的发生，从而较好地保持豆荚的食用品质，延长贮藏期。2和3ml／kg乙醇处理促进了食荚豌豆的衰老进程和腐烂发生，这可能与高浓度乙醇对豆荚产生伤害有关。     

大蒜精油的提取及微胶囊化的工艺研究

文章采用大蒜为原料，采用纤维素酶进行酶解，以95％的乙醇为溶剂，经浸渍和连续浸提所得的蒜素为心材，以食用胶为壁材，经均质、喷雾干燥而得大蒜油树脂微胶囊。通过正交试验获得微胶囊化的最佳工艺条件，最佳工艺条件为心材：壁材为1：3，进风温度150℃，进料速度为1．56L／h，进料浓度为35％。     

燃料乙醇精馏工艺的模拟优化与节能研究

将工业乙醇生产的一级精馏系统和燃料乙醇生产的加盐萃取精馏系统合并,在差压精馏节能技术的基础上,利用过程系统模拟软件ProII对蒸馏工艺进行模拟优化.醪塔:最佳理论塔板数为15块,塔顶压力为50kPa;精馏塔:最佳理论塔板数为30块,塔顶压力为200kPa,回流比为3.4;萃取精馏塔:塔顶产品乙醇体积浓度为99.8%(优级纯)时,所需最佳理论塔板数为30块,回流比为0.4,萃取剂和酒精质量比为1:2:1;萃取剂回收塔:在塔釜液含水量为0.2%(w/w)的前提下,最佳理论塔板数为10块,回流比为0.5.另外,采用热能耦合、闪蒸技术、设置中间再沸器等一系列节能措施,结合燃料乙醇生产的蒸煮工段,对热量进行充分利用,使冷却水以及加热蒸汽的用量大大减少.     

低沸点溶剂萃取八角油树脂的工艺研究

探讨了不同溶剂、pH值、料剂比、提取时间、八角果的颗粒度、乙醇浓度对八角油树脂提取率的影响，并时工艺条件料剂比、提取时间、八角果直径、乙醇浓度进行了四因素三水平的正交优化试验。结果表明最佳工艺条件为：料剂比（g／mL）15：100，八角果直径0．105mm（即100目），用95％乙醇回流3h，提取率可达40．14％。     

含水乙醇蒸汽脱水的生物质吸附性能研究

使用恒温固定吸附床对乙醇蒸汽脱水的生物质吸附剂的吸附性能进行研究。考查了床层温度、进料浓度、表观气速和吸附剂粒径对吸附性能的影响。实验结果表明,在87％（w／w）乙醇／水蒸汽,吸附剂对乙醇的吸附量最小。降低床层温度,接近蒸汽冷凝点温度;减小粒径,增大吸附剂单位比表面积;减小进料速度,增大停留时间都将有利于吸附操作。在吸附剂吸附量一定的情况下,进料浓度提高,水的吸附量增大。     

从芹菜中提取黄酮类物质的研究

本文以西芹为原料,针对芹菜的生理特点,采用乙醇提取,用分光光度法测定的方法,进行了从芹菜中提取黄酮类物质的研究,发现预处理对芹菜叶和芹菜茎有不同的作用。分别考察了从芹菜叶和芹菜茎中用乙醇回流法提取黄酮类化合物的最佳条件:芹菜叶的提取是在 85～90℃、回流时间6h、物料比1:40、乙醇浓度95% 。芹菜茎的提取是在75～80℃、回流时间4h、物料比1:60、乙醇浓度80% 。     

柿叶中黄酮提取工艺的研究

本文主要研究了柿叶黄酮的醇法提取工艺.首先就乙醇浓度、回流时间、回流温度及固液比进行了单因素实验.然后结合单因素的实验结果,设计了四水平三因素正交试验,最终得到柿叶总黄酮的最佳提取工艺为回流温度90℃,乙醇浓度55%,回流时间6h,提取工艺固液比为120.     

苦瓜黄酮的提取条件及其抗氧化活性研究

本研究以乙醇为溶剂,以乙醇浓度、回流时间、回流温度等做L9(33)正交试验研究苦瓜中黄酮类物质的最优提取工艺,并比较了各提取液的抗氧化能力。实验结果表明:在乙醇浓度为70%,回流温度为40℃,回流时间为3h的条件下苦瓜中黄酮类物质的提取率最高126.56mg/100g,且其对·OH的清除率也最好75.37%,接近于VC对·OH的清除率80.10%。     

金银花中绿原酸提取工艺的优化

对金银花中绿原酸的提取方法进行了比较研究,探讨了乙醇回流法的最佳提取方法和最佳工艺条件,并采用微波和酶液处理金银花以改进乙醇回流法.乙醇回流法最佳条件是加10倍量75%乙醇,回流提取1.5 h.对于乙醇回流法的改善,微波筛选的最佳工艺条件是:在600W微波功率下,样品预浸时间24 h,辐射时间2min.纤维素酶处理的酶用量为0.5%浓度2mL,最适温度为40℃～50℃,最佳时间为3.0h.试验表明:优选得到的工艺简单、稳定、可行,微波及酶液处理均能显著提高绿原酸的得率.     

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.     

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.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the