芒果皮中黄色素不同提取方法的比较

以芒果皮为原料,对其黄色素的不同提取工艺和提取效果进行了比较。通过实验得到溶剂法最佳提取条件为:提取剂为体积分数95%乙醇,料液比1∶8(g∶mL),提取温度60℃,提取时间3 h,提取次数为2次,浸提率为83.75%;超声波辅助法最佳提取条件为:提取剂为体积分数95%乙醇,料液比1∶9(g∶mL),超声波功率250W,超声波处理时间30 min,提取次数为2次,浸提率为87.68%。结果表明,超声波辅助法的浸提率较溶剂法有所增加,且超声波辅助法处理时间短,仅为溶剂法的1/6,是一种短时高效的提取方法。     

不同提取方法对辣椒红色素提取得率的比较研究

以红辣椒为原料,采用溶剂法、超声波溶剂提取法、微波溶剂提取法、超临界CO2流体萃取法得到的辣椒红色素进行了色价、产率比对,并对色素的质量进行检测.结果表明,超声波溶剂提取法、微波溶剂提取法、超临界CO2流体萃取法明显优于溶剂浸提法;超临界CO2流体萃取法提取率高于超声波溶剂提取法和微波溶剂提取法;超声波协助提取、微波溶剂提取相比,超声波协助提取不需要加热,不会破坏有用的成分,利用率高.     

超声波辅助与溶剂萃取枇杷仁油方法比较研究

以枇杷仁为原料,对2种提取枇杷仁油的工艺和效果进行比较。通过正交实验得到溶剂法提取枇杷仁油的最佳工艺条件为:溶剂选用石油醚(b.p 60~90℃),料液比1∶8(g∶mL),提取时间2 h,提取温度80℃,枇杷仁油收率为10.3%;超声波辅助法提取枇杷仁油的最佳工艺条件为:溶剂选用石油醚,料液比1∶5(g∶mL),超声温度60℃,超声时间25 min,超声功率180 W,枇杷仁油收率为12.9%。结果表明,超声波辅助法提取的枇杷仁油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度要低,是一种短时高效的提取方法。     

提取柿叶黄酮类化合物工艺研究

研究3种不同浸取柿叶黄酮类物质的工艺方法及优化工艺参数,通过正交试验,得出超声波水提法、超声波溶剂提取法和微波溶剂提取法的最佳工艺条件,3种方法在最佳工艺条件下的黄酮类物质提取量依次为5.28%、6.19%和6.15%;超声波水提法经济适用,适合生产化,超声波溶剂提取法和微波溶剂提取法所得提取黄酮类物质较高,比超声波水提法高出约0.8%。     

超声波与溶剂萃取西瓜籽油的对比研究

以西瓜籽为原料,对2种提取西瓜籽油的工艺和效果进行比较。通过正交试验得到溶剂法提取西瓜籽油的最佳工艺条件为:溶剂选用石油醚(b.p.60～90℃),料液比1∶8(g∶mL),提取时间2 h,提取温度80℃,西瓜籽油提取率为48.2%;超声波辅助法提取西瓜籽油的最佳工艺条件为:溶剂选用石油醚,料液比1∶6(g∶mL),超声温度50℃,超声时间50 min,超声功率150 W,西瓜籽油提取率为50.8%。结果表明,超声波辅助法提取的西瓜籽油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度低,是一种短时高效的提取方法。     

超声波辅助与溶剂萃取枇杷仁油的对比研究

以枇杷仁为原料,对两种提取枇杷仁油的工艺和效果进行比较。通过正交试验得到溶剂法提取枇杷仁油的最佳工艺条件为：溶剂选用石油醚,料液比1：8(g:mL),提取时间2 h,提取温度80 ℃,枇杷仁油提取率为10.3%;超声波辅助法提取枇杷仁油的最佳工艺条件为：溶剂选用石油醚,料液比1：5(g:mL),超声温度60 ℃,超声时间25 min,超声功率180 W,枇杷仁油提取率为12.9%。结果表明,超声波辅助法提取的枇杷仁油得率比溶剂法高,并且超声波辅助法比溶剂法提取的时间短、温度要低,是一种短时高效的提取方法。     

不同方法提取丝瓜籽油的工艺研究

以丝瓜籽为原料,对丝瓜籽油的不同提取工艺和提取效果进行了比较.通过正交试验得到溶剂法最佳提取条件为:提取溶剂选用石油醚(b.p.60～90℃),提取时间为3 h,料液比为1:8(g:mL),提取温度为60℃,提取次数为2次,提取率为17.93%.超声波辅助法最佳提取条件为提取溶剂选用石油醚.超声时间为40min,超声功率为120 W,料液比为1:12(g:mL),超声温度为50℃,提取次数为2次,提取率为18.76%.结果表明,超声波辅助法提取的丝瓜籽油提取率高于溶剂提取法的提取率,并且比溶剂法提取的温度低、时间短,是一种短时高效的提取方法.     

超声波提取小叶榕叶总黄酮工艺研究

以小叶榕叶为原料，用正交试验法优化小叶榕叶总黄酮的超声波提取工艺，考察超声波作用时间、超声波功率、液料比和乙醇浓度4个因素对小叶榕叶总黄酮提取率的影响，确定小叶榕叶总黄酮的优化超声波提取工艺条件为：提取溶剂60％乙醇，料液比1：30，超声波功率为240w，超声波作用时间20min。将该法与常规热提取法进行对比。结果表明，超声波提取小叶榕叶总黄酮的提取率比常规热提取的提取率要高，而且超声波提取所用提取时间短，提取溶剂用量少。     

超声波提取亚麻籽油脂工艺及其对亚麻籽微观结构影响研究

为优化亚麻籽油脂超声波辅助提取工艺,在单因素试验基础上,以提取温度、提取时间、超声功率、液料比为变量,以亚麻籽油脂得率为响应值,采用Box-Behnken试验设计方法对工艺条件进行优化,并对超声波辅助提取与溶剂提取法得到的亚麻籽油脂中脂肪酸组成差异及其对亚麻籽微观结构的影响进行了比较研究。结果表明：优化后得到的超声波辅助提取最佳工艺条件为温度66℃、时间33min、功率180W、液料比13mL?g-1,在该工艺条件下亚麻籽油脂得率为35.52%,与理论预测值无显著差异。扫描电镜(SEM)分析结果表明,与普通溶剂提取法相比,超声波提取可有效破坏亚麻籽表面结构,提高油脂浸出率,气相色谱(GC)分析结果显示溶剂提取与超声波辅助提取法得到的亚麻籽油脂脂肪酸组成结构与含量并无明显差异。     

丰年虫油的超声波辅助提取工艺

以丰年虫为原料,利用超声波辅助法进行提取,筛选提取丰年虫油的最佳溶剂,选择超声波功率、料液比、提取时间和提取温度4个因素进行单因素试验,并在此基础上进行L27(313)正交试验。结果表明：超声波辅助提取丰年虫油的理想溶剂为乙酸乙酯,最佳工艺条件为超声波功率150W、料液比1:10(g/mL)、提取时间40min、提取温度60℃,在该条件下丰年虫的出油率可达84.83%。超声波辅助提取与溶剂法相比,有提取时间短、油脂品质较好等优点。     

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.