八角和八角残渣总黄酮提取工艺优化

目的：确定八角和八角残渣中总黄酮的最佳提取工艺。方法：采用乙醇热回流法提取八角和八角残渣中的黄酮类化合物,通过单因素试验和正交试验,考察乙醇体积分数、料液比、提取时间、提取次数对八角和八角残渣中总黄酮提取率的影响。结果：八角总黄酮提取最佳条件为：80% 乙醇、料液比1:30、提取时间120min、提取次数3 次。八角残渣总黄酮最佳提取条件为：乙醇体积分数50%、料液比为1:10、提取时间120min、提取次数3 次。结论：在最佳工艺条件下,八角总黄酮提取率为23.61%,八角残渣总黄酮提取率为16.81%。     

香菜总黄酮的超声提取工艺研究

确定香菜总黄酮的优选超声提取工艺条件。采用正交试验法，考察溶剂浓度、超声时间、料液比、提取次数对提取率的影响，用分光光度标准曲线法测定含量。所考察的因素中，香菜总黄酮的提取影响程度为：溶剂浓度〉提取次数〉超声时间〉料液比。超声提取的最佳条件为95％乙醇，超声30min，料液比1：20，提取4次。与常规的提取方法相比，具有提取时间短、简单、收率高无需加热等优点。     

骨碎补总黄酮水提工艺的优化

目的:优化骨碎补总黄酮的水浸提提取工艺。方法:以总黄酮提取率为指标,在单因素预试验基础上,通过正交实验设计对影响总黄酮提取率的提取时间、料液比、提取次数等因素进行优化。结果:骨碎补水浸提提取最佳工艺为提取时间1h、料液比1∶10、提取次数3次。在此工艺条件下,骨碎补总黄酮提取率为1.04%。结论:优化的骨碎补总黄酮水浸提提取工艺稳定可行,为骨碎补总黄酮的开发利用提供实验依据。     

回归正交法优化杜仲叶中总黄酮提取工艺的研究

以杜仲叶为原料,采用索氏提取法对其有效成分总黄酮进行提取.以正交实验考察了提取过程中的各影响因素,再以回归正交实验优化了提取工艺.结果表明:影响杜仲叶总黄酮提取率的因素顺序为:乙醇浓度>料液比>提取时间>提取次数>提取温度>pH;最佳工艺条件为:提取时间38.66min、料液比1:12.09、乙醇浓度67.14%,在最佳工艺条件下提取率可达1.55%.     

微波提取藏茵陈总黄酮的工艺

本文用微波提取法提取出了藏茵陈中总黄酮,通过化学方法对藏茵陈中总黄酮进行了定性鉴定,设计了正交试验考察影响总黄酮提取率的4个因素,设计单因子试验确定了这四大因素的最佳提取条件。结果表明：藏茵陈提取液中含有黄酮类化合物;微波提取藏茵陈中总黄酮的4个因素对提取效果影响的次序为乙醇浓度〉微波功率〉微波提取时间〉料液比,最佳的提取工艺为料液比1∶35,乙醇浓度70%,微波功率700W,微波提取时间8min,该工艺条件下总黄酮提取率达5.56%     

超声波提取桑葚果渣黄酮工艺研究

本文研究了超声波辅助提取的温度、时间和料液比对桑椹果渣总黄酮的提取的影响,经单因素以及正交试验,表明在使用甲醇∶乙醇=3︰1的浓度为70%的混合醇作为提取液时,最佳的提取条件为提取时间60min、提取温度70℃、料液比1︰35;各因素对提取率的影响为：温度〉料液比〉时间。     

瓜馥木总黄酮提取工艺研究

优选瓜馥木总黄酮提取工艺。采用传统乙醇溶剂热回流提取黄酮,利用紫外分光光度法测定黄酮含量。通过单因素实验考察温度、乙醇浓度、料液比、提取时间和提取次数对黄酮提取率的影响规律,并通过正交实验确定各因素对黄酮提取率的影响。黄酮最佳提取工艺条件为温度75℃,乙醇浓度60%,料液比1:25,提取时间4.0 h,提取次数5次,平均黄酮提取率为6.805%。     

海红果中总黄酮提取工艺研究

以海红果为原料,在单因素试验的基础上,采用二次回归正交旋转组合设计,研究了提取海红果中总黄酮的最佳工艺参数。结果表明,4个参试因素对海红果中总黄酮的提取率影响大小顺序依次为：料液比〉乙醇浓度〉提取时间〉提取温度;其最佳提取工艺条件为乙醇浓度60%、料液比1∶50、提取温度40℃、提取时间150min。在此优化条件下,提取的海红果中总黄酮含量可达0.2900%。     

纤维素酶提取冬枣叶中总黄酮工艺的研究

采用纤维素酶提取冬枣叶中的总黄酮.以芦丁为标准品,采用分光光度法测定冬枣叶中总黄酮的含量,通过单因素实验研究提取温度、提取时间、酶用量和料液比对提取率的影响,再利用正交实验优化最佳提取工艺条件.结果表明,纤维素酶提取冬枣叶中总黄酮的最佳工艺条件为:料液比1:50(g/mL),提取温度55℃,提取时间90min,酶用量4mg/g.在最佳提取工艺条件下,提取率可达2.45％.同时得到各影响因素对总黄酮提取率的显著性影响顺序为:提取温度＞提取时间＞酶用量＞料液比.     

煮制加工对绿豆中黄酮含量的影响

煮制过程是绿豆饮料加工的重要步骤,试验分别考察了料液比、煮制温度、煮制时间和p H值对绿豆煮制液中黄酮含量的影响,在单因素试验基础上通过正交试验对影响黄酮含量的因素进行了优化研究。试验结果表明:煮制温度和p H值对煮制液黄酮含量影响显著。最佳的煮制工艺参数为:p H值为7.5,煮制温度80℃,煮制时间1.6 h,料液比为1∶10(g/m L)。在此条件下,煮制液中黄酮含量为1.90 mg/m L。     

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