富集沙棘果油中棕榈油酸的工艺优化及脂肪酸分析

以青海沙棘果油为原料,利用化学酯交换法对沙棘果油中棕榈油酸进行富集,以棕桐油酸乙酯转化率为指标,分别研究了醇油体积比、反应温度、反应时间及KOH质量分数对沙棘果油中棕榈油酸富集的影响.再采用尿素包合法对棕榈油酸乙酯进行富集,并通过气相色谱串联质谱法对棕榈油酸富集物的组成进行分析.结果 表明:化学酯交换法的最佳工艺参数为...     

沙棘果油棕榈油酸提取物的富集及改善胰岛素抵抗活性

运用尿素包埋-分子蒸馏复合法提取沙棘果油中的棕榈油酸,在单因素试验的基础上采用响应面分析法优化提取工艺参数,并利用气相色谱法对产物脂肪酸组成进行分析。通过高浓度胰岛素诱导HepG2细胞建立胰岛素抵抗模型,探索沙棘果油提取物改善胰岛素抵抗活性。结果表明,尿素包埋和分子蒸馏两步法提取沙棘果油中的棕榈油酸最佳条件为:尿素包埋法,尿素与底物比1.98∶1(g/g)、溶剂与尿素比4.03∶1(mL/g)、包埋时间12.15 h;分子蒸馏法,进料速率0.84 mL/min、刮膜速率116.02 r/min,蒸馏温度99.75℃。采用气相色谱检测棕榈油酸含量,结果表明在最佳优化条件下棕榈油酸质量分数显著提高,达到72.19%(模型预测值为68.02%),证明所建立的方法可用于沙棘果油中棕榈油酸的富集和纯化;体外实验表明沙棘果油中棕榈油酸提取物浓度达到100μmol/L时可以明显改善糖原合成水平,达到200μmol/L时可以显著性缓解胰岛素抵抗导致的葡萄糖消耗量降低现象,证明沙棘果油棕榈油酸提取物具有改善胰岛素抵抗的功能。     

尿素包合法分离油用牡丹籽油的不饱和脂肪酸工艺优化研究

采用正交实验设计对尿素包合法富集牡丹籽油不饱和脂肪酸工艺进行优化。考察了包合反应中尿素与乙醇质量体积比、包合温度、包合时间对产品中α-亚麻酸含量的影响。结果表明:最佳工艺条件为尿素与95%乙醇质量体积比3∶9、包合温度0℃、包合时间15 h,尿素包合后α-亚麻酸含量达64.95%。尿素包合法可有效地富集牡丹籽油中的不饱和脂肪酸,并且可以提高α-亚麻酸的含量。     

超临界CO2萃取石榴籽油及石榴酸甲酯富集

采用超临界CO2 萃取技术从石榴籽中提取石榴籽油,对其脂肪酸和甘三酯组成和含量进行分析;通过单因素和正交优化试验研究尿素包合法富集石榴酸甲酯。超临界CO2 萃取技术与有机溶剂萃取相比更有利于获得高石榴酸含量的石榴籽油,石榴籽油中检测出14 种甘三酯。尿素包合法富集石榴酸甲酯的最佳工艺为尿素包合温度5 ℃、包合时间20 h、尿素与脂肪酸甲酯的质量比1∶1、尿素和95%乙醇的质量比1∶5,此最佳包合条件下获得的石榴酸甲酯的含量为78.82%。     

溶剂结晶和尿素包合法提高油酸纯度的研究

以24度精炼棕榈油水解脂肪酸为原料,通过使用溶剂结晶和尿素包合法进行分离提纯制备较高纯度的油酸。通过对实验条件的优化,得到溶剂结晶的最佳条件为:m(无水乙醇)∶m(混合脂肪酸)=2∶1,结晶温度-10℃,结晶时间10 h;尿素包合的最佳条件为:m(原料酸)∶m(尿素)∶m(无水乙醇)=1∶2∶10,包合温度10℃,包合时间6 h。通过溶剂结晶和尿素包合法得到了含量为87.56%的高纯油酸产物,油酸产物的总得率为38.65%。     

尿素包合法富集文冠果油中神经酸的研究

以文冠果籽为原料,低温压榨制取文冠果油,对文冠果油脂肪酸组成进行分析;采用尿素包合法对文冠果油中的神经酸进行富集,以神经酸含量和回收率为考察指标,通过单因素实验和正交实验优化工艺条件。结果表明:文冠果油中含量在1%以上的脂肪酸共有8种,主要脂肪酸为油酸(27.76%)和亚油酸(44.87%),神经酸含量为2.59%;最佳尿素包含富集文冠果油中神经酸工艺条件为尿脂比1∶1、料液比1∶10、包合温度10℃、包合时间8 h,在此条件下神经酸回收率为74.01%,油脂中神经酸含量为9.49%,较未包合前提高约3倍,比稀缺的元宝枫籽油中神经酸含量(约5%)高出近1倍,是一种典型的功能性油脂。     

低温溶剂分提与分子蒸馏复合法富集沙棘果油棕榈油酸的工艺研究

以沙棘果油水解后的混合脂肪酸为原料,在正己烷-丙酮(体积比1∶1)与粗制混合脂肪酸体积比1∶1、分提温度-5℃、分提时间12 h下采用低温溶剂分提法富集棕榈油酸,再采用分子蒸馏法对低温分提混合脂肪酸进行富集,以达到富集沙棘果油棕榈油酸的目的。通过单因素试验对分子蒸馏条件进行优化,得到最佳的分子蒸馏工艺条件为真空度5 Pa、蒸馏温度95℃、进料速度1 mL/min、刮膜器转速220 r/min。在最佳条件下进行二次分子蒸馏,棕榈油酸含量从沙棘果油的30. 74%提高到72. 56%,轻相得率为30. 90%。进一步将产物进行低温溶剂分提后,棕榈油酸含量可达78. 30%。     

沙棘果油中棕榈油酸分离方法的研究

棕榈油酸对糖尿病和心脑血管疾病等具有生理调节作用,但由于棕榈油酸来源较为稀少,限制了其开发利用。经研究发现沙棘果油中含有较为丰富的棕榈油酸,可作为棕榈油酸原料,但其分离工艺还未见报道。以沙棘果油为原料,对比CO_2超临界萃取法、尿素包埋法和分子蒸馏法3种方法分离棕榈油酸,建立了一种高效从沙棘果油中分离棕榈油酸的方法,即尿素包埋与分子蒸馏复合法,使用此方法可以将棕榈油酸含量从先前的占果油脂肪酸得30%提高到70%,此方法也为沙棘的高值化利用和棕榈油酸的工业化生产提供参考。     

响应面法优化黑加仑籽油中γ-亚麻酸富集工艺

采用响应面优化尿素包合法富集黑加仑籽油中γ-亚麻酸的最佳工艺。在单因素试验基础上,选择包合温度、尿素/混合脂肪酸配比、95%乙醇/尿素配比(mL/g)、包合时间为考察因素,进行四因素三水平的Box-Behnken中心组合设计,采用响应面法分析4个因素对籽油中γ-亚麻酸含量的影响。结果表明,尿素包合法富集黑加仑籽油中γ-亚麻酸的最佳工艺为包合温度-20℃、尿素/混合脂肪酸配比3.5∶1、95%乙醇/尿素配比2.5∶1(mL/g)、包合时间21h,在此条件下,包合后籽油中γ-亚麻酸含量平均值为24.27%。     

尿素包合法富集苦瓜籽油中α-桐酸的工艺优化北大核心CSCD

以超临界CO;萃取的苦瓜籽油为原料,经皂化酸解法制得混合脂肪酸,再采用尿素包合法富集其中的α-桐酸。在单因素试验的基础上,采用正交试验对富集工艺条件进行优化。结果表明,α-桐酸的最佳富集工艺条件为:采用95%乙醇作为尿素溶剂,混合脂肪酸与尿素质量比1∶3,尿素与95%乙醇质量比1∶5,包合温度4℃,包合时间24 h。在最佳工艺条件下,α-桐酸纯度从苦瓜籽油中的28.83%提高至60.03%,产物中共轭亚麻酸相对含量达到71.28%。     

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