微波法提取决明子中蒽醌工艺条件的优化研究

采用微波提取方法，微波功率为750W，以决明子中蒽醌的含量为考察指标，研究提取溶剂浓度、料液比、提取温度、提取时间等因素对蒽醌提取效果的影响。通过正交试验，确定微波提取决明子中蒽醌的最佳工艺条件为：乙醇浓度70％，料液比1：5，提取温度60℃，提取时间10min，在此条件下获得的总蒽醌提取率为65％。     

微波辅助循环萃取法脱除茶叶咖啡因研究

探讨了利用微波辅助萃取技术高选择性脱除茶叶中咖啡因的新方法,在料液比1∶50,微波功率160W,微波时间6min的条件下,以沸水为溶剂,咖啡因脱除率高达80.56%,茶多酚损失率为40.16%。优化工艺以茶叶萃取液为溶剂,采用循环萃取的方式,则可以控制茶多酚损失率降至12%。进一步探索性尝试4℃冷藏静置12h的方法进行萃取液循环利用,促使咖啡因以络合物的形式沉淀、脱除。在最优条件下,连续生产茶叶9批次后仍可保持47.02%的脱除率,并且茶多酚的损失率小于11.74%。     

微波辅助萃取蜂胶中黄酮类化合物的研究

利用微波辅助萃取法提取蜂胶中的黄酮类化合物,考察了微波提取条件（溶剂浓度、微波功率、提取时间、料液比）对蜂胶中黄酮提取率的影响,采用分光光度法测定提取液中黄酮的含量。结果表明：乙醇浓度为80%,微波提取功率为80W,提取时间为1.5min,料液比为1：4时,提取效果最佳。微波辅助法与传统提取法相比,具有提取效率高,时间短,节省溶剂用量等特点。     

微波提取山楂果中原花青素工艺的研究

采用微波提取方法,微波功率为340W,以山楂果中原花青素含量为考察指标,研究提取溶剂种类、浓度、料液比、提取时间、提取次数等因素对原花青素提取效果的影响.通过正交实验,确定微波提取山楂果中原花青素的最佳工艺条件为：提取溶剂60%乙醇,料液比1：10,提取时间210s,提取2次.     

微波辅助水蒸汽蒸馏法和无溶剂微波萃取法提取孜然精油工艺的研究

采用微波蒸馏法提取孜然精油,考察微波溶剂提取和无溶剂提取孜然精油工艺中微波提取时间、微波功率、粒度和液料比等因素对孜然精油提取率的影响。同时以枯茗醛含量作为精油品质的评价指标,并通过GC对孜然精油进行分析。研究结果表明,微波溶剂提取孜然精油的最佳工艺条件为：液料比6:1、微波提取时间90min、微波功率300W,此条件下精油提取率为3.501%,精油中枯茗醛含量为19.121%。微波无溶剂提取孜然精油的最佳工艺条件为：浸泡时间30min、微波提取时间45min、微波功率200W,此条件下精油提取率为2.461%,精油中枯茗醛含量为23.910%。     

微波辅助提取"转心乌"洋芋皮红色素的研究

采用单因素和正交试验设计,应用微波辅助溶剂浸提法提取转心乌洋芋皮天然红色素,对影响色素收率的微波功率、微波时间、提取料液比等主要因素进行了优化组合试验,以确定最佳提取条件。通过试验比较了色素收率结果表明:在微波功率、微波时间、提取料液比三因素中,微波功率对色素收率影响最大,其次是微波时间,提取料液比的影响较小。单因素和正交试验结果确定的最佳工艺组合为:1%HCl水溶液为提取溶剂,微波功率400W,微波时间15min,提取料液比为1:10(g/mL)。在此试验条件下,平行试验3次,转心乌洋芋皮红色素平均收率可达86.79%,与传统溶剂浸提法相比,红色素收率可提高15.85%,微波辅助溶剂浸提法能高效提取转心乌洋芋皮中天然红色素。     

茶叶中咖啡因提取方法的比较

茶叶是人们生活中的重要饮品,我国茶叶的产销量居世界前列。如何更好地高效利用我国每年滞销的5万多吨中低档茶叶,是广大茶叶利用研究工作者和茶农们的共同心声。而茶叶中具有许多生物生理活性物质,其中咖啡因就是当中含量较高的一种。我们以绿茶为原料,通过L16(45)正交试验考察了微波辅助提取法从茶叶中提取咖啡因的影响情况,并以传统的Soxhlet提取法为对照。正交试验表明,从茶叶中提取咖啡因的最佳提取方案为:微波功率0.2kW、提取剂80%(v/v)乙醇、料液比为1:16(m/V)、浸提时间9min(间隙式提取)、温度83±5℃、连续提取3次,使用自制复合中和沉淀剂,咖啡因提取率平均达到217.5mg/10g茶样,较Soxhlet法提取6h的144.8mg/10g茶样高50.2%,最高可达221.8mg/10g茶样,比Soxhlet法的148.8mg/10g茶样高49.1%。而且微波法所得咖啡因的纯度、外观和稳定性等质量指标明显优于Soxhlet法。这为传统的茶叶提取咖啡因工艺的升级改造提供了实验依据。     

微波法提取决明子红色素的工艺研究

以决明子红色素浸提率为指标,采用单因素试验法和正交试验法考察了提取剂的类型、料液比、微波功率、萃取时间、次数5个因素。对影响决明子红色素提取的工艺条件进行优化研究。试验结果表明：对微波提取决明子红色素的影响顺序依次为：提取时间〉微波功率〉提取次数〉料液比;优化工艺条件为提取时间4min,微波功率为320W,提取次数为3次,料液比为1：40,溶剂是乙酸乙酯。该条件下进行验证试验,决明子红色素浸提率可达91％。     

微波预处理法提取番茄皮中番茄红素的工艺研究

本实验研究了微波预处理法提取番茄皮中番茄红素的提取工艺条件,探讨了浸润溶剂用量、液料比、微波预处理时间、微波功率对番茄红素提取效果的影响。本实验最佳提取工艺条件:浸润溶剂用量为8ml,液料比为8∶1,微波功率720w,微波预处理60s。     

微波辅助提取玫瑰茄籽油工艺的研究

应用微波加热技术,对玫瑰茄籽进行干燥处理;以石油醚为溶剂,采用回流法提取玫瑰茄籽油。利用正交实验探讨微波处理温度、微波处理时间、提取时间、提取温度和料液比对玫瑰茄籽油提取得率的影响。结果表明,影响玫瑰茄籽油提取得率的因素主次顺序为：料液比〉微波处理温度〉提取温度〉微波处理时间〉提取时间;最佳提取工艺条件：料液比为1：9、微波处理温度为90℃、提取温度为50℃、微波处理时间为150s、提取时间为3h,得率为14.08%,提取率为85.5%。     

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