超临界CO2流体萃取小麦胚芽油工艺的研究

本文根据超临界流体萃取的基本原理,分析了影响超临界CO2流体萃取小麦胚芽油的主要因素,它们包括萃取压力、温度、时间、CO2流量、小麦胚芽水分含量及粒度等,通过正交试验和单因素试验研究了小麦胚芽油的萃取量与各因素之间的关系并确定了最佳的试验条件即为:萃取压力为32～36MP,温度为45～50℃、时间为6h,CO流量为15～20kg/ h,小麦胚芽水份含量为5.0%,粒度为10～15目。     

超临界CO_2流体萃取小麦胚芽油最佳工艺条件研究

本文根据超临界流体萃取基本原理,分析影响超临界ＣＯ２流体萃取小麦胚芽油主要因素,包括萃取压力、温度、时间、ＣＯ２流量、小麦胚芽水分含量及粒度等,通过正交试验和单因素试验研究了小麦胚芽油萃取量与各因素之间关系并确定最佳试验条件,即:萃取压力为 ３２~３６ＭＰａ,温度为 ４５~５０℃、时间为６小时,ＣＯ２流量为 １５~２０ｋｇ/ｈ,小麦胚芽水份含量为５．０%,粒度为１０~１５目。     

不同萃取条件对麦胚中天然维生素E的SFE-CO_2提取的影响

研究以小麦胚芽为试验材料 ,利用超临界流体萃取技术从麦胚中提取了天然维生素E。结果表明 :麦胚中天然维生素E的超临界CO2 适宜萃取条件为萃取压力 2 8～ 35MPa、萃取温度 40～ 45℃、CO2 流量 2mL/min、萃取时间 90min。     

麦胚中天然维生素E的SFE-CO_2最佳提取工艺的研究

本研究以小麦胚芽为原料 ,利用超临界流体萃取技术从麦胚中提取天然维生素E。将萃取压力、萃取温度和CO2 流量作为中心组合旋转设计的变量 ,进行响应曲面分析 ,确定了其最佳工艺参数和条件。结果表明 :麦胚中天然维生素E的超临界CO2 提取的最佳工艺参数为萃取压力为2 9 1MPa ,萃取温度为 316K ,CO2 流量为 2ml/min。     

麦胚中天然维生素E的SFE—CO2最佳提取工艺的研究

本研究以小麦胚芽为原料,利用超临界流体萃取技术从麦胚中提取天然维生素E。将萃取压力、萃取温度和CO2流量作为中心组合旋转设计的变量,进行响应曲面分析,确定了其最佳工艺参数和条件。结果表明：麦胚中天然维生素E的超临界CO2的取的最佳工艺参数为萃取压力为29.1MPa,萃取温度为316K,CO2流量为2ml/min。     

超临界CO2流体萃取小麦胚芽油工艺研究

研究了超临界二氧化碳萃取小麦胚芽油的工艺,分别讨论了萃取时间、萃取温度、萃取压力和二氧化碳流量对小麦胚芽油萃取得率的影响。结果表明：萃取小麦胚芽油的最佳工艺条件为萃取时间为3h、萃取温度为50℃、萃取压力30MPa、CO2流量8L／h,出油率为10．5％。     

超临界CO2萃取不同筋度小麦胚芽油及其脂肪酸成分分析

采用超临界CO2萃取技术,以高、中、低筋小麦胚芽为原料,通过正交试验分析方法,主要研究超临界CO2萃取小麦胚芽油的萃取压力、萃取温度和萃取时间3个因素对于小麦胚芽油萃取率的影响。结果表明,在萃取压力30MPa、萃取温度50℃、萃取时间2h的条件下萃取效果最佳,萃取率为11.05%。运用气相色谱技术分析不同筋度小麦胚芽油的脂肪酸成分组成,其中低筋小麦胚芽萃取出的小麦胚芽油中亚油酸相对含量高达58.23%。     

小麦胚芽VE营养油制备方法的比较研究

本课题对不同方法直接萃取小麦胚芽油及用超临界CO2流体精馏麦胚油的方法进行了比较研究。结果表明:用乙醚提取的小麦胚芽油中维生素E的含量比用乙醇(90%)提取的要高;用超临界CO2萃取在压力为33MPa,温度为45℃时有最高的维生素E含量;用超临界CO2精馏在压力为19MPa,温差为△t=9℃时有较好的维生素E浓集效果。     

大豆胚芽油的超临界CO2萃取研究

通过超临界CO2流体萃取大豆胚芽油的实验,探讨了萃取压力、萃取温度、萃取时间和CO2流量对大豆胚芽油萃取率的影响。结果表明,最适宜的萃取条件为萃取压力30MPa、萃取温度45℃、萃取时间120min、CO2流量25kg/h,在此条件下萃取率为91.38%;超临界CO2法得到的大豆胚芽油不饱和脂肪酸含量为84.2%,其中亚麻酸和亚油酸占74%,碘值为152gI/100g。     

玉米胚芽油的超临界CO2萃取

研究了超临界CO2流体萃取玉米胚芽油的条件,着重研究了萃取压力、温度、萃取时间和CO2流量对油脂萃取率的影响,优化了萃取工艺条件;萃取压力35MPa,温度50℃,时间3h,CO3流量34kg/h,并利用GC／MS分析了最佳条件下萃取的玉米胚芽油成分组成。并比较了超临界CO2萃取的玉米胚芽油样和乙醚萃取油样的理化性质。     

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.