水洗脱除生物柴油中甘油的工艺研究

甘油是生物柴油生产过程中的主要副产物。生物柴油中甘油含量多少是评价生物柴油质量好坏的重要指标之一。通过水洗可以很容易去除粗生物柴油中的游离甘油,采用单因素试验研究影响水洗脱除甘油的因素,再用正交法优化工艺条件。结果表明：水洗脱除甘油的最优条件为：水洗温度40℃、水洗次数4次、搅拌时间25min、搅拌速度250r/min,此时的甘油脱出率85.49%。生物柴油经最佳工艺条件水洗,其甘油残留量为0.0065%,符合美国ASTMD6751-02的标准规定。     

从生物柴油副产物甘油中分离磷脂的研究

以生物柴油副产物甘油为原料,用丙酮为溶剂分离得到丙酮不溶物(粗磷脂).研究了液料比、提取分离温度、提取分离时间和搅拌速度对提取率的影响.用响应面法进行优化,最佳分离条件为:V(无水丙酮):m(甘油)为12:1,提取分离温度16℃,提取分离时间13 min,搅拌速度372r/min.经验证实验,提取率达到98.9%.     

生物柴油副产品粗甘油中甾醇的提取研究

本文介绍了生物柴油副产品甘油中甾醇的提取工艺,通过单因素试验得出最佳皂化条件为碱浓度1mol/L,皂化时间45min,并通过正交试验设计得出植物甾醇的最佳萃取工艺条件：萃取剂用量308mL、萃取时间25min、搅拌速度313r/min、萃取温度35℃,植物甾醇的提取率达到4.02mg/g。     

活化稻壳灰在生物柴油纯化中的应用研究

对稻壳灰进行活化,并比较了活化稻壳灰与几种常见吸附剂对生物柴油的吸附纯化效果.选择活性白土与活化稻壳灰复配对生物柴油进行吸附纯化,确定最佳配比为2∶3,吸附剂添加总量为0.5％.并在吸附温度、吸附时间、搅拌速度等单因素试验结果的基础上,通过正交试验优化了吸附纯化生物柴油的最佳工艺参数为:吸附温度70℃,吸附时间60 min,搅拌速度1 600 r/min.     

β-环糊精脱除猪油中胆固醇的研究北大核心CSCD

为脱除猪油中胆固醇、提高猪油品质,研究以猪油为原料,选择β-环糊精包合法、硅胶吸附法和分子蒸馏法对猪油进行胆固醇脱除,分析了3种方法脱除胆固醇效果和对猪油酸值、过氧化值的影响。结果表明,β-环糊精包合法优于另外两种方法。然后对β-环糊精脱除猪油中胆固醇的工艺条件进行优化,以胆固醇脱除率为指标,考察β-环糊精添加量、水油比、搅拌时间对胆固醇脱除率的影响,通过单因素实验和响应面实验分析得到β-环糊精脱除猪油中胆固醇最佳工艺条件为β-环糊精添加量2.8%、水油比1.2∶1、搅拌时间41 min、搅拌温度50℃、搅拌速度1 000 r/min,在最佳工艺条件下胆固醇脱除率为67.54%。回收β-环糊精重复利用5次胆固醇脱除率为61.9%,仍具有很高的脱除效率。     

β-环糊精脱除猪油中胆固醇的研究

为脱除猪油中胆固醇、提高猪油品质,研究以猪油为原料,选择β-环糊精包合法、硅胶吸附法和分子蒸馏法对猪油进行胆固醇脱除,分析了3种方法脱除胆固醇效果和对猪油酸值、过氧化值的影响。结果表明,β-环糊精包合法优于另外两种方法。然后对β-环糊精脱除猪油中胆固醇的工艺条件进行优化,以胆固醇脱除率为指标,考察β-环糊精添加量、水油比、搅拌时间对胆固醇脱除率的影响,通过单因素实验和响应面实验分析得到β-环糊精脱除猪油中胆固醇最佳工艺条件为β-环糊精添加量2.8%、水油比1.2∶1、搅拌时间41 min、搅拌温度50℃、搅拌速度1 000 r/min,在最佳工艺条件下胆固醇脱除率为67.54%。回收β-环糊精重复利用5次胆固醇脱除率为61.9%,仍具有很高的脱除效率。     

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%.     

化学法生物柴油生产工艺改进研究

以棉籽油为原料,探讨了化学法制取生物柴油过程中以吸附剂处理替代水洗干燥的精制工艺.通过正交试验研究了吸附剂处理对生物柴油质量的影响.结果表明:在吸附剂用量、混合时间和吸附温度3个因素中,吸附剂用量影响最大,其次为混合时间,吸附温度的影响最小.用1.5%和2%吸附剂在70 ℃下搅拌处理20～25 min后的产品质量明显强于吸附剂其他处理方式得到的生物柴油产品质量,主要指标能达到中国生物柴油国家标准<柴油机燃料调合用生物柴油(BD100)>的相关要求.     

响应面法优化生物柴油的氧化脱色工艺

脱色环节是生物柴油精炼的一个重要部分。以废动植物油制备的生物柴油为脱色对象,通过氧化脱色研究了脱色剂种类、脱色剂用量、脱色温度、脱色时间、搅拌速度对生物柴油脱色率的影响。以脱色率为考察指标,在单因素试验的基础上,采用中心组合试验设计及响应面法优化了生物柴油的脱色工艺。结果表明:过氧化苯甲酰的脱色效果最好,在脱色温度80.8℃、脱色时间45 min、过氧化苯甲酰用量为生物柴油质量的32.1%、搅拌速度200 r/min条件下,生物柴油脱色率达到45.31%。     

内部沸腾法提取葡萄皮花色苷研究

采用单因素试验和正交试验对内部沸腾法提取葡萄皮花色苷工艺进行研究,探讨乙醇体积分数、提取温度、提取时间和水料比对葡萄皮花色苷提取的影响。确定最佳提取工艺参数为:乙醇体积分数90%、提取温度85℃、提取时间5 min、提取水料比30 m L/g。按此优化条件,提取效果最佳,试验重现性好。     

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