尿素包合分离核桃油中亚油酸工艺优化

对尿素包合分离核桃油中亚油酸的工艺进行了优化,在单因素实验基础上,利用响应面法优化包合温度(℃)、包合时间(h)、m1(混合脂肪酸)∶m2(尿素)、V(95%乙醇)∶m2(尿素)四个因素对亚油酸纯度和得率的影响。结果表明尿素包合核桃油中亚油酸最佳工艺参数为:包合温度-10℃、包合时间24h、m1(混合脂肪酸)∶m2(尿素)为0.3、V(95%乙醇)∶m2(尿素)为4。在此条件下,经过一次尿素包合,亚油酸的纯度可由原来的52.1%上升到80.20%。     

尿素包合法纯化玉米油中亚油酸的研究

研究了尿素包合过程中回流时间、包合时间、包合温度、尿素与溶剂配比等主要条件与纯化得到的亚油酸纯度和得率的关系.结果表明,尿素与溶剂配比是影响亚油酸纯度和得率的主要因素.当尿素/乙醇为1:2(W/V)时,亚油酸的纯度和得率均较高,当混合脂肪酸/尿素/乙醇为1:3:6(W/W/V)时,在室温下,通过一次尿素包合就能使亚油酸的纯度从44.48%提高到95.68%,得率为72.41%.     

山桐子油中亚油酸的纯化工艺及体外抗氧化性研究

利用高效液相色谱法,在单因素试验基础上结合响应面法对尿素包合纯化的亚油酸纯度和得率进行分析,并进行抗氧化活性分析。结果表明:纯化亚油酸的最佳工艺条件为尿素/混合脂肪酸质量比2:1、包合温度-5℃、包合时间10 h,在此条件下亚油酸纯度为87.952%、得率为87.951%,并且对DPPH和ABTS⁺自由基具有一定的清除效果。     

脲包法富集高纯度红花油亚油酸甲酯的研究

以亚油酸含量 81 74 %的红花油为原料 ,采用先碱性醇解 ,后尿素包合的方法 ,从红花油中富集亚油酸。通过正交试验 ,确定了尿素一次包合法富集高纯度亚油酸甲酯的最佳工艺条件 :混合脂肪酸甲酯∶尿素∶甲醇为 1 0 4∶1∶4 (W/W /V) ,包合温度 - 10℃ ,包合时间 2 4h ,亚油酸甲酯得率 72 95 % ,纯度 99 2 7%。     

尿素包合法纯化葡萄籽油中亚油酸的研究

利用尿素包合法对葡萄籽油中亚油酸的分离纯化进行研究.分析了包合温度、包合时间、甲醇尿素质量比、混合脂肪酸尿素质量比4个因素对亚油酸纯度及得率的影响,并在单因素实验的基础上通过正交实验确定最佳工艺条件.结果表明:在包合时间12h,包合温度-4℃,甲醇尿素质量比5∶1,混合脂肪酸尿素质量比1∶1的条件下,亚油酸纯度最高为89.9％.     

尿素包合法纯化棉籽油中亚油酸的研究

利用尿素包合法对棉籽油中亚油酸进行纯化研究.通过正交试验确定其最佳提取条件,结果表明:尿素/甲醇为3:1,脂肪酸,尿素用量为0.8:1,包合时间为24 h,包合温度为-5 ℃,在此条件下亚油酸纯度达到90.7%.     

尿素包合法对葵花籽油中亚油酸的富集研究

本文以葵花籽油为原料,以制备多不饱和共轭亚油酸及尿素包合法纯化亚油酸的工艺进行了研究,重点考察了皂化温度、稀硫酸的浓度、离心转速、离心时间、95%乙醇与尿素配比(v/w)、尿素与脂肪酸配比(w/w)以及尿素包合时间对富集效率的影响。结果表明:最佳分离纯化工艺条件为皂化温度80℃、稀硫酸浓度20%、离心转速3 000r/min、离心时间10min、95%乙醇尿素比为3∶1、尿素脂肪酸比为1.5∶1和尿素包合时间12h。     

华山松籽油亚油酸的富集纯化及降血脂活性研究

以华山松籽油为原料,通过皂化酸解得到混合脂肪酸,再通过尿素包合法富集纯化亚油酸,研究了包合温度、包合时间、混合脂肪酸与尿素质量比值、95%乙醇与尿素体积质量比值4个因素对亚油酸纯度和得率的影响。然后采用不同剂量的纯化亚油酸对高脂模型小鼠进行灌胃,研究其降血脂功能。通过单因素试验确定富集纯化亚油酸的最佳工艺条件为:包合温度-10℃,包合时间24 h,混合脂肪酸与尿素质量比值0.4,95%乙醇与尿素体积质量比值5。在最佳条件下,经一次尿素包合,得到的亚油酸纯度为80.57%。降血脂功能研究结果表明:由华山松籽油富集纯化得到的亚油酸具有降低高脂血症小鼠体重、肝脏重及肝脏指数、小鼠血清甘油三酯(TG)及总胆固醇(TC)水平,提高小鼠血清高密度脂蛋白胆固醇(HDL-C)水平,降低动脉硬化指数(AI)及低密度脂蛋白胆固醇(LDL-C)水平的功能。由华山松籽油富集纯化得到的亚油酸可降低高脂血症小鼠血脂水平,改善其因摄入过多脂质而导致的肝脏脂肪堆积和动脉粥样硬化。     

尿素包合法提纯油茶籽油中油酸的工艺研究

用尿素包合法对油茶籽油中的油酸进行包合。采用浸出法、直接酸解法和浸出后酸解法分离包合物固相中的油酸。实验结果表明,选用直接酸解法效果较好。尿素包合条件为脂肪酸/尿素/甲醇(W/W/V)比例1∶4∶10,通过包合,油酸的纯度从包合前的66.99%提高到77.96%。     

尿素包合法纯化火棘籽油亚油酸与鲨烯工艺

以火棘籽油为原料,采用尿素包合法对其亚油酸进行纯化,并在此基础上通过柱层析分离出鲨烯。通过单因素试验、正交试验和气相色谱-质谱联用(gas chromatography-mass spectroscopy,GC-MS)分析方法,研究尿素包合过程中包合时间、包合温度及火棘籽油、尿素和乙醇之间的配比等因素对亚油酸纯度和回收率的影响。结果表明：火棘籽油在原料:尿素:乙醇＝1:2:6(g/g/mL)、－5℃条件下包合12h,其亚油酸纯度从38.40%提高到68.55%,回收率达72.23%;纯化后的火棘籽油再经柱层析分离得到鲨烯,纯度达98.16%。     

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