响应面法优化金柚核中类柠檬苦素的 提取工艺

在单因素试验的基础上,选择超声时间、超声温度和料液比为自变量,柚核中柠檬苦素类物质的提取率为响应值,进行Box-Benhnken中心组合试验设计,运用响应面分析法优化梅州金柚核柠檬苦素类物质的提取工艺。结果表明,梅州金柚核柠檬苦素类物质超声提取最佳工艺为提取温度50℃,料液比1∶20(g/m L),超声时间20 min。此工艺下柠檬苦素类物质提取率为0.491 mg/g(RSD=1.13%,n=3),与理论值0.487 mg/g偏差很小。     

常山胡柚皮柠檬苦素提取工艺

利用高效液相色谱法对常山胡柚皮中柠檬苦素的含量进行测定,比较了有机溶剂提取、水提取、超声波辅助提取条件下,常山胡柚皮中柠檬苦素的提取得率。结果表明:用乙醇提取时,提取温度50℃,料液比1∶20(g/m L),提取时间60 min,柠檬苦素得率为2.97 mg/g;用水提取时,提取温度80℃,料液比1∶25(g/m L),提取时间90 min,柠檬苦素得率为2.42 mg/g。超声辅助提取时,以乙醇作为提取溶剂,柠檬苦素得率为3.32 mg/g;以水作为提取溶剂,柠檬苦素得率为2.87 mg/g。     

陈皮柑橘籽中柠檬苦素类物质提取工艺的比较研究

为探索新会陈皮柑橘籽中柠檬苦素类物质的适合提取方法,本实验采用有机溶剂(丙酮)提取法和水溶助剂(水杨酸钠)提取法分别对其中的柠檬苦素类物质的提取工艺进行优化研究,并比较两者的提取率。结果表明:有机溶剂提取法最优条件为:时间3.2h,温度68.2℃,料液比1∶64.8,此条件下的提取率为4.97mg/g;水溶助剂提取法的最优提取条件为:时间5.6h,温度51.8℃,料液比1∶8,水杨酸钠浓度2mol/L,此条件下的提取率为5.19mg/g。两种提取方法的比较:水溶助剂法提取率更高,但是操作较繁琐,有机溶剂法操作简单,提取率相对较低。     

响应面法优化橘核中3种柠檬苦素类成分的超声辅助提取工艺

研究橘核中3种柠檬苦素类成分的超声提取辅助工艺。根据单因素试验结果,采用响应面法对提取工艺进行优化。结果显示优化提取工艺为甲醇作提取溶剂、提取时间40 min、提取温度33℃、液料比13∶1(mL/g),在此条件下柠檬苦素类成分总得率为11.804 5 mg/g,与模型预测值11.756 9 mg/g基本一致,该方法可用于提取橘核中的柠檬苦素、诺米林和黄柏酮。     

索氏法提取柚籽中柠檬苦素工艺优化研究

目的 通过响应面优化得到索氏法提取柚籽中柠檬苦素的最佳工艺。方法 样品粉碎过60目筛, 在一定体积的乙醇水溶液中索氏提取一定时间, 高速冷冻离心机离心得到提取液, 稀释、加样、显色, 在491 nm下测定吸光度, 计算安江香柚籽中柠檬苦素的含量。结果 乙醇浓度、提取时间、液料比对安江香柚籽中柠檬苦素的提取均有显著影响; 响应面优化后的提取工艺为: 乙醇浓度90%、提取时间2.2 h、液料比40:1 (mL/g), 得到柠檬苦素提取率最大值11.36 mg/g。结论 利用索氏法提取安江香柚籽中的柠檬苦素方法可行, 效果明显。     

响应面法优化柑橘皮柠檬苦素提取工艺

为优化柑橘皮中柠檬苦素的提取工艺,在单因素试验基础上,采用响应面分析法研究了提取时间、提取温度和液料比对柑橘皮柠檬苦素得率的影响,建立具有良好预测性能的数学模型,通过响应面分析法确定柑橘皮中柠檬苦素最优提取工艺条件。试验结果表明,提取温度和液料比对柑橘皮柠檬苦素得率的影响显著,最优提取条件为:提取时间20h,提取温度为51.5℃和液料比为96∶3(mL/g)。     

酸性水提取柑橘皮渣柠檬苦素工艺

以使用硫酸调节纯水得到的酸性水为溶剂,采用高效液相色谱测定柠檬苦素含量,浸提柑橘皮渣中柠檬苦素。在热浸提时间、温度及料液比单因素试验的基础上,利用三元二次旋转组合试验设计优化提取条件,建立三因素与柠檬苦素得率之间的数学模型。结果表明,酸性水提取柑橘皮渣中柠檬苦素的最佳工艺条件为提取时间2.6h、温度61.2℃、料水比1:19.2(g/mL)、酸性水提取液pH4。在此工艺条件下,柠檬苦素的得率为0.117mg/g。     

脐橙皮中柠檬苦素的双水相提取及显色研究

以低温烘干的脐橙皮为原料,利用乙醇-硫酸铵双水相体系提取脐橙皮中的柠檬苦素。利用分光光度计法,研究显色温度等因素对柠檬苦素显色性质的影响,得出最合适的显色温度为30℃。在此基础上,建立柠檬苦素的标准曲线,并通过单因素试验和正交试验考察了乙醇浓度、料液比、硫酸铵用量、提取温度和提取时间对提取率的影响。结果表明:当乙醇体积浓度为60%,料液比为1∶20(g/m L),硫酸铵用量为12 g,提取温度为50℃,提取时间为4 h时,提取率最高。在此条件下作了5次平行试验,平均得率可达0.345 3%,而且试验重现性好。     

甜橙皮渣中柠檬苦素类似物提取工艺研究

以硫酸调节的酸性水为提取剂,采用单因素实验和正交实验探讨了料液比、提取温度、时间和提取剂pH对甜橙皮渣中柠檬苦素类似物提取的影响,并确定了最佳的工艺参数为温度65℃、时间1.5h、提取剂pH为4、料液比1∶12,在该工艺路线下提取柠檬苦素类似物的得率为1.19mg/g(鲜重)。     

陈皮中柠檬苦素的响应面提取及其抗炎作用研究

以陈皮为原料,研究陈皮柠檬苦素超声辅助提取工艺及其抗炎作用。采用超声提取陈皮柠檬苦素,利用响应面分析法优化其提取工艺,并对陈皮柠檬苦素对小鼠植入棉球致肉芽肿和小鼠扭体产生抑制作用进行分析。表明陈皮柠檬苦素萃取最佳工艺条件为:液料比32∶1(m L/g)。超声功率为265.1 W,超声提取时间为30 min,乙醇体积分数为85.3%。对小鼠植入棉球致肉芽肿研究表明陈皮柠檬苦素有较强的抗炎作用。     

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