萃取法制备透明浓缩磷脂的工艺研究

本实验对用萃取方法制得透明浓缩磷脂的工艺进行了深入研究。选取正己烷、乙醇作为萃取剂,除无机杂质最佳工艺条件为：正己烷1.5ml/g,静止时间1.5h;脱除糖类物质最佳工艺条件为：无水乙醇1ml/g,搅拌温度25℃,时间4min,搅拌速度100r/min。制得浓缩磷脂含糖量1.15%,得率90%,其无机杂质0.05%、丙酮不溶物62.06%、水分及挥发物1.0%,外观澄清透明。     

超临界CO2从大豆粗磷脂中萃取分离磷脂

以大豆粗磷脂为原料,通过超临界CO2萃取进行了提纯磷脂的研究。考察了萃取温度、萃取压力、萃取时间对萃取效果的影响,并通过正交实验对萃取磷脂工艺条件进行了优化。实验结果表明,最佳工艺参数为:萃取压力35 MPa,萃取温度50℃,萃取时间5.5 h。在最佳条件下,提纯磷脂中丙酮不溶物达98.2%。     

芝麻油浓缩磷脂提取工艺条件的研究

以水代法和机榨法制取的芝麻毛油静置沉淀后的底部沉淀物（即芝麻油脚）为原料,利用正己烷萃取除杂、水化浓缩及絮凝分离的方法从中提取芝麻油浓缩磷脂,并对水化浓缩和絮凝分离的工艺条件进行了研究。结果表明：正己烷萃取除杂（条件为料液比1∶8、时间6 h、温度25℃）后芝麻油脚中固体不溶性杂质含量从21.25%降低至0.04%;水化浓缩的最佳条件为水与萃取除杂油脚质量比4.5∶1、水化时间40 min、水化温度85℃,水化浓缩后丙酮不溶物含量从3.41%提高至45.87%;絮凝分离的最佳条件为预热温度40℃、反应温度90℃、NaCl添加量3%、反应时间20 min,所得浓缩磷脂的丙酮不溶物含量为56.82%。     

丙酮萃取蛋黄磷脂工艺研究

研究了以磷脂酰胆碱萃取率为指标,利用正交试验优化丙酮萃取蛋黄磷脂工艺中料液比、萃取温度、萃取时间等参数,并考察了超声对磷脂酰胆碱萃取率的影响。得到最佳萃取条件:不超声,萃取温度20℃,料液比1∶7,萃取时间70 min。在最佳条件下,PC萃取率可达96.955%。     

溶剂萃取技术制备粉状大豆磷脂

以膏状大豆磷脂为原料，用丙酮为溶剂制备了粉状磷脂。对萃取参数进行了优化，研究了洗涤次数，溶剂与膏状磷脂的比，丙酮中水的含量及萃取时的温度对粉状磷脂的纯度的影响。用正交设计优化工的萃取条件。在12℃，洗涤5次，膏状磷脂（g）：溶剂（ml）=30：250，萃取2min可得纯度为98．5％的粉状磷脂。     

超临界CO2萃取粉末磷脂的研究

本文以非转基因大豆浓缩磷脂为原料,利用溶剂及吸附剂去除杂质及多环芳烃得到精制大豆浓缩磷脂,经超临界CO2萃取得到大豆粉末磷脂,并通过实际生产到得到超临界CO2萃取大豆粉末磷脂。精制大豆浓缩磷脂的条件为,正己烷添加量为1.5 mL/g,凹凸棒添加量为5%,时间3 h,温度50 ℃,搅拌速度1 500 r/min,精制大豆浓缩磷脂含杂质量为0.05%,多环芳烃量为2.29 μg/kg。经超临界CO2萃取条件为,萃取压力35 MPa,萃取温度50 ℃,萃取时间130 min,得到的粉末磷脂含杂质量为0.03%,多环芳烃量为1.83 μg/kg。通过实际生产,精制大豆浓缩磷脂含杂质量为0.08%,多环芳烃量为2.97 μg/kg。超临界CO2萃取粉末磷脂含杂质量为0.06%,多环芳烃量为2.45 μg/kg,HLB值可以达到8。     

芝麻油渣中磷脂的超临界提取及分析研究

以芝麻油渣为原料提取芝麻磷脂,参照GB/T 5537-2008《粮油检验磷脂含量的测定》,采用优化的钼蓝比色法建立了磷脂的分析方法,并对芝麻油渣中磷脂含量进行测定,研究超临界CO_2提取芝麻磷脂过程中萃取压力、萃取温度、萃取时间对出油率的影响,确定最佳提取工艺条件。试验结果表明,采用优化的钼蓝比色法测定分析芝麻油渣中磷脂含量,测定快速,准确度较高,试验范围内得到的最佳提取工艺条件为CO_2流量10 L/h,原料粒径范围20目~40目,萃取压力18 MPa,萃取温度45℃和萃取时间120 min,在此条件下油脂萃取率达到12.5%。将超临界萃取得到的油脂进行水化脱胶,离心分离得到磷脂富集层,用正己烷溶解并用丙酮沉淀,得到芝麻磷脂,磷脂的提取率为35.58%,所得磷脂的纯度为65.90%。     

高纯度大豆粉末磷脂制取工艺的研究

本项目以大豆浓缩磷脂为原料 ,丙酮为溶剂 ,采用溶剂比为 1∶12～ 18(浓缩磷脂 :丙酮 )的量 ,连续投料 ,高效混合 ,循环萃取的方法脱油 :脱油后的磷脂混合液在密闭的条件下离心分离 ;分离出的混合油经蒸发、冷凝回收毛油及丙酮 ,若丙酮含水高则经精馏塔精馏后再循环使用 ,含溶固体物在真空度 75 0mmHg、温度 6 0℃、时间约 2h的工艺技术条件下干燥 ,制得丙酮不溶物含量大于 95 %以上的高纯度大豆粉末磷脂产品。不但产品质量达到国内外指标 ,而且显示出良好的亲水性能 ,成为优良的天然食品添加剂和保健品     

膜过滤法制备食品级浓缩磷脂

以粗大豆浓缩磷脂为原料,采用无机膜过滤方式制取高质量浓缩磷脂.研究了膜孔径、溶料比、膜过滤温度、物料流速和水分含量对膜通量、丙酮不溶物含量和磷脂得率的影响.实验结果表明,水分含量0.1%,膜孔径0.20μm,溶料比6:1,过滤温度50 ℃,物料流速3 m/s为最佳工艺条件.在最佳条件下,产品中丙酮不溶物含量可达到60%以上,最高可达65%以上;且乙醚不溶物含量可以稳定地控制在0.05%以下.     

山杏内种皮磷脂类化合物提取工艺研究

研究利用微波法辅助提取山杏内种皮磷脂类化合物的最佳工艺。以总磷脂得率为评价指标,单因素实验考察萃取温度、萃取时间、微波功率、料液比对磷脂得率的影响,正交实验优化提取条件。山杏内种皮磷脂类化合物最佳提取工艺为:萃取时间15 min,微波功率400 W,料液比1:25(g/mL),萃取温度45 ℃。在此条件下总磷脂得率为0.0977%±0.0015%。高效液相色谱法分离测定磷脂类化合物,测得磷脂酰乙醇胺(PE)含量为(0.3936±0.0082) mg/g。该法为山杏资源的充分利用提供了一定的数据支撑。     

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.     

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.     

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.     

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.     

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.