微波提取香草兰豆荚中香兰素及其抗氧化活性研究

根据Box-Behnken中心组合实验设计,采用响应面分析优化了微波提取香草兰豆荚中香兰素的工艺条件,并对其抗氧化活性进行研究。得到的微波提取香草兰豆荚中香兰素的最佳提取工艺条件为:乙醇体积分数80%、料液比1:18.6 g/mL、微波时间5 min、微波温度55℃、微波功率350 W,此条件下香兰素提取率为8.883 mg/g。香兰素提取液具有较好的抗氧化活性,对DPPH自由基和羟自由基清除率分别达65.326%和89.471%,IC_(50)分别为150.538、63.271μg/mL。香草兰豆荚中的香兰素具有一定的抗氧化能力,是很有应用价值的天然食品添加剂。     

雪菊中抗氧化活性物质的提取工艺研究

通过单因素实验和正交试验,考察不同因素如提取剂浓度、提取温度、提取时间、料液比等对雪菊中抗氧化成分提取效果的影响,确定最佳提取工艺条件。结果表明:在超声提取工艺下,影响提取效果的主次因素为料液比提取温度提取溶剂提取时间,最佳提取工艺条件为料液比1∶8、提取温度65℃、提取溶剂70%乙醇、提取时间3.5h。     

响应面法优化大豆豆荚甾醇提取工艺的研究

研究大豆豆荚甾醇的乙醇溶液提取,单因素实验考察了几个因素对甾醇收率的影响,在此基础上选择液料比、乙醇体积分数、提取时间和提取温度,用响应面法以四因素三水平对大豆豆荚甾醇提取工艺进行优化,建立甾醇提取条件与收率之间的模型并进行分析,以期获得最优的工艺参数,提高甾醇的收率。结果表明:液料比、乙醇体积分数、提取时间和提取温度对收率影响均显著;所得模型显著;乙醇溶液提取大豆豆荚中甾醇的最佳工艺条件为液料比25.4 mL/g、乙醇体积分数73.5%、提取时间1.64 h、提取温度71.3℃,甾醇理论最高收率3.12 mg/g;采用该工艺,实际甾醇收率为3.08 mg/g。     

不同萃取工艺香草兰萃取物成分研究

本文利用95％乙醇和超临界CO2流体分别萃取香草兰豆荚，对萃取物的香气成分GC／MS分析，并用NIST107LIB、NIST21LIB数据库检索，分别鉴定出28种和31种化合物；用高效液相色谱测定萃取物中香兰素的含量。结果表明，两种萃取方法得到的香气物质其化学组成有较大差别。     

固相微萃取和同时蒸馏萃取法分析海南香草兰挥发性成分

对固相微萃取（solid phase micro-extraction,SPME）技术萃取香草兰中挥发性成分的萃取条件进行优化, 并采用SPME和同时蒸馏萃取（simultaneous distillation extraction,SDE）两种方法对海南地区香草兰豆荚中挥发 性成分进行检测分析。结果表明：SPME最优萃取条件为萃取头75 μm CAR/PDMS、萃取温度80 ℃以及萃取时 间20 min。2 种萃取方法共检测出105 种挥发性成分,其中利用SPME技术检测出挥发性成分73 种,SDE检测出78 种。结果表明：将SPME和SDE两种方法联合使用可以更加全面地检测出香草兰中的挥发性成分。     

香荚兰豆中香兰素葡萄糖苷的提取、分离及表征

为进一步拓展天然香兰素的开发途径,采用超声辅助溶剂萃取法从香荚兰豆中提取了香兰素葡萄糖苷粗提物,以香兰素葡萄糖苷提取率为指标,通过单因素试验和正交试验对粗提物提取工艺进行了优化,并利用制备高效液相色谱技术分离获得了香兰素葡萄糖苷单体。结果表明:①粗提物最佳提取工艺为萃取时间10 min、萃取温度65℃、固液比1∶11、萃取功率140 W,在此条件下香兰素葡萄糖苷提取率为1.88%;②当流动相中0.5%(质量分数)乙酸水溶液和甲醇比例为80∶20(体积比)时,利用制备高效液相色谱可有效分离纯化香兰素葡萄糖苷,产品得率为1.36%;③采用~1H NMR和~(13)C NMR对产品进行结构表征,进一步验证了所得产品为目标化合物香兰素葡萄糖苷。该提取分离工艺处理量较大、步骤简便、成本低廉,可为天然香兰素葡萄糖苷单体开发提供参考。     

超声波提取豆荚总黄酮优化工艺与抗氧化性研究

以大豆豆荚为原料,以超声波法提取黄酮化合物.结果表明,豆荚黄酮的最佳提取工艺条件为:乙醇浓度70%,料液比1:25(w/v)、萃取时间20 min、超声波功率270 W、浸提次数为3次.在此最佳工艺条件下进行试验,测得豆荚总黄酮得率为8.49%.豆荚总黄酮具有较强的体外抗氧化活性.     

罗汉果白酒调味液的工艺研究

以罗汉果为原料,采用冷凝回流浸提工艺生产罗汉果白酒调味液。通过单因素和正交试验研究料液比、酒精浓度、提取温度和提取时间对罗汉果甜苷提取效果的影响,获得最佳罗汉果白酒调味液的工艺条件。最佳工艺条件为:料液比1:20,酒精浓度为65%,提取温度为70℃,提取时间为3h。最佳工艺条件下生产的罗汉果白酒调味液经GC-MS分析,共鉴定出43种香气成分,主要的香气成分是亚油酸、棕榈酸和亚油酸甲酯。     

响应面法优化葵花籽中绿原酸的提取工艺

研究了向日葵籽中提取绿原酸的主要参数:乙醇浓度、液料比、提取温度、料液pH、提取时间等对绿原酸萃取率的影响。通过在单因素实验基础上进行3因素3水平的Box-Behnken实验,得到了优化的工艺条件:乙醇浓度为75%、pH为4.9、温度为40℃、液料比为1:14,提取99min的条件下提取3次,绿原酸的萃取率可达到64.73%。     

响应面优化串叶松香草总黄酮的提取工艺及其抗氧化活性研究

通过响应面法对串叶松香草中的总黄酮提取工艺进行优化。根据Box-Behnken中心组合原理,在醇提法和单因素实验法基础上将显著效应的四个单因素:液料比、提取时间、提取温度及提取液乙醇浓度进行四因素三水平的响应面设计实验,以获得串叶松香草总黄酮提取工艺参数,并测定串叶松香草中总黄酮的抗氧化活性。最优实验工艺条件为:液料比31:1 mL/g、提取时间129 min、提取温度38 ℃、乙醇浓度42%。在此条件下获得的总黄酮提取量高达(38.93±0.012) mg/g,与理论值相差0.04%。1 mg/mL的串叶松香草总黄酮(0.51 mg)对DPPH自由基的清除率为73.06%,0.6 mg/mL的串叶松香草总黄酮ABTS+自由基的清除率为100%,6 mg/mL的串叶松香草总黄酮还原力为0.188,说明串叶松香草总黄酮具有较强的自由基清除活性,具有一定还原力。     

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