高纯度磷脂酰肌醇的提取工艺研究

以低磷脂酰胆碱(PC)含量大豆粉末磷脂为原料,建立以碱性乙醇为溶剂结合冷冻纯化制备高纯度磷脂酰肌醇(PI)的方法。在单因素实验的基础上利用响应面优化实验确定PI的最佳提取条件为:冷冻时间17 h,冷冻温度-20℃,提取温度40℃,料液比1∶27,98%乙醇与25%氨水体积比100∶4,提取时间40 min,提取次数3次。在最佳条件下,产物PI含量为82.62%,得率为14.29%。     

大豆磷脂酰乙醇胺的分离及纯化

以提取卵磷脂(PC)后的大豆粉末磷脂为原料,以碱性乙醇为溶剂提取磷脂酰乙醇胺(PE),并进行冷冻纯化。在单因素实验的基础上,以PE得率为指标,响应面优化实验确定了PE的最佳提取条件为:提取温度45℃,料液比1∶20,乙醇碱浓度V(无水乙醇)∶V(25%氨水)=100∶2,提取时间50 min,提取次数2次。在最佳条件下,PE得率为79.53%,含量为48.42%;当冷冻温度为-15℃,冷冻时间为8 h时,PE含量提升到72.73%,得率为66.71%。     

注射级大豆磷脂提取工艺的研究

采用乙醇加热提取和冷冻纯化的方法,从大豆粉末磷脂提取PC含量在72%~85%,PE含量在5%~10%范围内的大豆磷脂产品。考察了乙醇体积分数、料液比、提取温度、提取时间、冷冻温度、冷冻时间对产品得率和PC、PE含量的影响,在PC、PE含量符合要求的情况下以得率最高为优。结果表明理想提取工艺为乙醇体积分数95%,料液比1∶4,提取温度60℃,提取时间45 min,冷冻温度-15℃,冷冻时间30 min。在该条件下产品的得率为22.26%,PC含量为77.02%,PE含量为8.63%。     

脱糖大豆粉末磷脂中磷脂酸的分离

以低磷脂酰胆碱(PC)含量的脱糖大豆粉末磷脂为原料,建立了使用酸性乙醇为溶剂分离高纯度磷脂酸的方法。探讨了提取温度、料液比、提取时间、提取次数、酸醇比和pH等因素对磷脂酸提取效果的影响,并在单因素实验的基础上通过响应曲面优化实验进行分析,得到分离磷脂酸的最佳工艺条件为:提取温度42℃,料液比1∶37(m/m),酸醇比1.2∶100(V_(25%HCl)∶V_(无水乙醇)),提取时间70min,沉淀pH为8。在最佳条件下,产物的HPLC分析表明,产品中PA含量为80.96%,回收率为70.53%。     

低PC含量大豆粉末磷脂脱糖工艺研究

以低PC含量大豆粉末磷脂为原料,在单因素实验基础上利用正交实验对磷脂脱糖工艺进行优化。研究结果表明,最佳工艺条件为:温度为30℃、时间为70 min、V(正己烷)∶V(乙醇)为1∶2、乙醇体积分数为50%、萃取次数为2次,此时脱糖率为89.7%,粗糖中糖的含量为89.2%。利用高效液相色谱法对提取的糖种类进行鉴定,结果表明这些糖为水苏糖、蔗糖、棉籽糖,其含量分别为71.1%、17.3%、6.6%。     

芝麻卵磷脂提取工艺条件研究

以芝麻浓缩磷脂为原料,利用丙酮提取除油得到芝麻粉末磷脂,再采用乙醇提取法对其中的卵磷脂(磷脂酰胆碱(PC))进行提取分离。通过单因素试验和正交试验得到最佳提取分离条件为:乙醇体积分数95%,料液比1∶12,提取温度50℃,提取时间20 min。在最佳条件下,卵磷脂提取率为27.92%,产品中PC含量为53.31%。     

α-亚麻酸乙酯的富集纯化及工艺研究

亚麻籽油经乙酯化得到混合高级脂肪酸乙酯,采用冷冻结晶法和尿素包合法对混合高级脂肪酸乙酯进行纯化,得到高纯度的α-亚麻酸乙酯。考察了尿素包合过程中尿素的用量、溶剂乙醇的用量、结晶温度、结晶时间等单因素对纯化效果的影响。并由正交试验确定了包合过程的最佳工艺条件。研究发现：当m（脂肪酸乙酯）∶m（尿素）∶V（乙醇）为1.5∶4∶6、结晶温度0℃、结晶时间16 h时,α-亚麻酸乙酯的含量可以提高到89%以上,得率可以达到60%以上。     

乙醇冷冻提取法纯化磷脂酰胆碱(PC)的工艺研究

为了得到纯度较高的磷脂酰胆碱,对乙醇冷冻提取法纯化磷脂酰胆碱的工艺进行了研究.采用高效液相色谱法测定磷脂酰胆碱的含量,通过正交实验设计考察了乙醇浓度、料液比和提取时间等因素在不同水平下对磷脂酰胆碱含量的影响,对试验结果进行了方差分析和显著性检验.结果显示乙醇冷冻提取法最佳工艺组合为A2B3C3,即93%乙醇溶液,料液比1：3,冷冻条件下提取8.5 h,在选定的最佳工艺条件下得到的磷脂酰胆碱的含量由原来的33%提高到了75%,可见乙醇冷冻提取法能有效地纯化磷脂酰胆碱.     

乙醇冷冻法纯化分离大豆磷脂酰胆碱研究

以大豆粉末磷脂为原料,结合乙醇萃取和乙醇冷冻纯化两个步骤提取纯化磷脂酰胆碱;重点探讨乙醇冷冻纯化步骤工艺条件,考察冷冻时间、冷冻温度、料液比、乙醇浓度等因素对乙醇冷冻纯化效果影响,并在单因素试验基础上进行正交试验,确定最佳冷冻纯化工艺为:冷冻时间6h,冷冻温度-12℃,料液比1:8,乙醇浓度97.5%,在此条件下纯化分离,磷酯酰胆碱含量由45.8%提高至70.5%、得率为81.2%。     

脂肪酶Bakezyme LFP水解大豆粉末磷脂研究

以酸值为指标,通过单因素实验和正交实验确定了脂肪酶Bakezyme LFP在水相中水解大豆粉末磷脂的最佳工艺条件为:反应温度为50℃,反应时间为8h,p H为5.0,加酶量为8%,底物质量浓度为25mg/m L。在该工艺条件下,大豆磷脂水解产物酸值为65.2mg KOH/g。利用气相色谱-质谱联用仪分析了水解前后大豆磷脂的脂肪酸组成,结果表明水解后饱和脂肪酸含量明显下降,不饱和脂肪酸含量明显增加,说明脂肪酶Bakezyme LFP主要水解大豆磷脂1位上脂肪酸,具有磷脂酶A1的特性。利用高效液相色谱分析水解前后大豆磷脂的磷脂酰乙醇胺(PE)和磷脂酰胆碱(PC)含量,结果表明大豆磷脂中PE、PC发生水解,生成溶血磷脂。     

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