油橄榄果渣中多酚提取工艺的优化

采用加热回流提取法,研究了浸提温度、乙醇浓度、料液比和浸提时间对油橄榄果渣多酚提取得率的影响。在单因素试验的基础上,通过正交试验对提取条件进行了优化,得到了油橄榄果渣中多酚的最优提取工艺:浸提温度为60℃、乙醇浓度为75%、料液比为1:13、浸提时间为4 h,油橄榄果渣多酚提取得率为0.2469%。     

蔗梢多酚提取工艺及抗氧化活性研究

植物多酚具有独特的生理活性和药理活性的天然产物,甘蔗的蔗梢部分多酚含量很高,但一般作为燃料直接燃烧,研究多酚的提取方法并研究其活性有一定的研究价值。在单因素试验的基础上采用正交试验得到了蔗梢多酚的最佳浸提工艺:浸提溶剂为60%乙醇,以1∶4固液质量比在60℃提取2h,在此条件下,蔗梢多酚浸提率为183mg/100g蔗梢。抗氧化活性实验表明,蔗梢多酚对花生油的抗氧化活性与VE接近。VC对其有明显增效作用,添加少量VC后,蔗梢多酚的抗氧化活性明显优于VE。     

正交实验法优选花椒多酚的超声波辅助提取工艺

采用超声波辅助提取法浸提花椒中的多酚类化合物,分别利用单因素实验和正交实验设计优化花椒多酚的浸提工艺参数条件。结果表明:提取剂(乙醇)的浓度对花椒多酚的提取具有显著性影响,花椒多酚超声辅助提取的最佳工艺条件为乙醇浓度60%,料液比1∶40,提取温度60℃,提取时间60min,按照此工艺参数条件浸提花椒多酚,多酚提取率高达(7.05±0.03)%。验证实验表明:正交实验法优化得到的花椒多酚超声波辅助提取工艺稳定可行,可作为花椒多酚提取的一种有效手段。     

拐枣枝多酚提取工艺优化及其抗氧化活性研究

采用响应面法优化拐枣枝多酚提取工艺,并研究其抗氧化活性,为拐枣枝多酚的应用提供理论依据。以拐枣枝为试验材料,在单因素试验的基础上选取浸提溶剂、料液比、浸提温度、浸提时间4个影响因素进行响应面优化试验;同时通过测定拐枣枝多酚对羟自由基、ABTS自由基、DPPH自由基的清除率来评估其抗氧化性。结果表明:拐枣枝多酚的最佳提取工艺为以无水乙醇为浸提剂,在料液比为1∶84(g/mL),浸提温度为60℃的条件下,浸提2.56 h,拐枣枝多酚的提取率为7.089%;拐枣枝多酚对羟自由基、ABTS自由基、DPPH自由基的最大清除率分别为90.97%、93.99%、97.19%。     

正交设计优化油橄榄果渣多酚提取工艺

以丙酮为溶剂,采用加热回流提取法,通过单因素试验考察了浸提温度、丙酮浓度、料液比和浸提时间对油橄榄果渣多酚提取率的影响,并在此基础上,通过正交试验设计得到了油橄榄果渣中多酚的最优提取工艺:浸提温度为60℃,丙酮浓度为75%,料液比为1∶13(g/m L),浸提时间为4 h,优选工艺提取的多酚含量为0.244 8%。     

油茶籽多酚的提取研究

研究从油茶籽中提取多酚的最佳工艺条件。设计溶剂对比试验,并在溶剂浓度、提取温度、时间、料液比、浸提次数这5个单因素试验的基础上,进行了正交试验,用FC法测定了油茶籽多酚的含量。油茶籽的最佳工艺条件：甲醇浓度50％,温度50℃,时间60min,料液比1：15（W：V）。     

响应面分析法优化龙眼核中多酚物质提取工艺

目的：利用响应面法对龙眼核中多酚物质的提取工艺进行优化。方法：在单因素试验基础上选取试验因素与水平,根据Box-Behnken Design(BBD)试验设计原理采用三因素三水平的响应面分析法,依据回归分析确定各工艺条件的影响因素,以龙眼核多酚物质含量为响应值作响应面和等高线图。结果：在分析各个因素的显著性和交互作用后,得出龙眼核多酚物质浸提的最佳工艺条件为乙醇体积分数70%、浸提温度77.4℃、浸提时间4h、料水比1:20(g/mL)、浸提2次,以焦性没食子酸为标准品,龙眼核多酚物质一次提取含量可达21.7079mg/g。结论：曲面回归方程与实验结果拟合性好,此模型合理可靠,可用于实际预测。     

荔枝果肉多酚的提取与分离

以荔枝果肉为试验材料,以多酚含量为评定参数,提取分离其中的多酚物质。以乙醇溶液为提取溶剂,通过单因素试验和正交试验,考察了浓度、提取时间、料液比、提取温度、浸提次数等影响提取率的几个重要因素,得出影响果肉中多酚提取的因素由大到小依次为,提取时间料液比乙醇浓度提取温度,最佳工艺条件为,乙醇浓度70%,料液比1∶11,浸提时间6 h,浸提温度40℃,浸提2次,而且荔枝果肉多酚主要以多酚的多聚体为主,其次是低聚体和单体。     

葡萄酒渣多酚的提取工艺优化

葡萄酒加工会产生大量的废弃物即葡萄酒渣,酒渣富含多酚类化合物等生物活性物质.通过单因素试验和正交试验,对葡萄酒渣多酚的浸提工艺进行了优化,确定最佳提取工艺条件为:以60 ％vol乙醇水溶液作为提取剂,料液比为1∶10,提取温度为70℃,提取时间为30 min,在此条件下多酚提取量可达39.56 mg/g.     

沙棘叶多酚在苹果汁保鲜中的应用

以沙棘叶为原料,多酚提取率作为考察指标,通过单因素及正交试验确定超声波辅助提取法提取沙棘叶多酚的最佳工艺条件,同时研究了沙棘叶多酚对天然苹果汁VC 保存的影响。结果表明,超声波辅助提取法最佳工艺条件为乙醇体积分数60%、浸提时间25min、料液比1:16。在此最佳工艺条件下,沙棘叶多酚提取量为7.385mg/g。沙棘叶多酚在苹果汁中的添加量为0.10%(质量分数)时,保鲜作用显著。     

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