利用餐饮废油制备生物柴油的研究

本文报道了利用餐饮废油和乙醇,在催化剂的作用下进行酯交换反应生成废油乙酯即生物柴油的试验研究,通过正交试验考察了反应条件如醇/油摩尔比、催化剂用量、反应温度、反应时间等对产率的影响,找出了餐饮废油酯交换反应的最佳反应条件.所生产的生物柴油符合美国ASTM生物柴油(B100)标准.     

复合碱性离子液体催化餐饮废弃油制备生物柴油北大核心CSCD

根据油脂的结构特点,研制了复合碱性离子液体催化剂;以三油酸甘油酯与甲醇的酯交换反应为模型,对酯交换反应的油醇摩尔比、反应时间、反应温度以及催化剂循环使用性进行了考察,并研究了该催化剂催化餐饮废弃油制备生物柴油的效果。结果表明:在油醇摩尔比为1∶9、反应时间为5 h、反应温度为120℃、催化剂用量为5%的条件下,三油酸甘油酯转化效果最佳,油酸甲酯产率高达96.2%;催化剂循环使用7次后油酸甲酯产率仍然保持在80%以上;在相同反应条件下,餐饮废弃油转化为生物柴油的产率最高可达93.6%。     

复合碱性离子液体催化餐饮废弃油制备生物柴油

根据油脂的结构特点,研制了复合碱性离子液体催化剂;以三油酸甘油酯与甲醇的酯交换反应为模型,对酯交换反应的油醇摩尔比、反应时间、反应温度以及催化剂循环使用性进行了考察,并研究了该催化剂催化餐饮废弃油制备生物柴油的效果。结果表明:在油醇摩尔比为1∶9、反应时间为5 h、反应温度为120℃、催化剂用量为5%的条件下,三油酸甘油酯转化效果最佳,油酸甲酯产率高达96.2%;催化剂循环使用7次后油酸甲酯产率仍然保持在80%以上;在相同反应条件下,餐饮废弃油转化为生物柴油的产率最高可达93.6%。     

稀土基磷钨酸催化大豆油与甲醇合成生物柴油及其工艺优化

以系列稀土改性磷钨酸为催化剂,大豆油与甲醇为原料进行酯交换反应制备生物柴油,考察各因素对生物柴油产率的影响,并通过响应面分析法优化制备工艺。研究表明,部分取代的稀土基磷钨酸催化剂具有较好的催化酯交换反应活性,其中Ce_(2/3)H_(1.0)PW_(12)O_(40)催化剂显示最好的生物柴油产率(94.4%)和重复使用性能,催化剂中Br?nsted酸中心和Lewis酸中心间的协同效应是其具有高催化性能的原因。响应面分析法优化生物柴油合成的最佳条件为:醇油物质的量比30∶1,催化剂量为大豆油质量的6.3%,反应时间20 h,反应温度148℃,该条件下生物柴油的产率为96.6%,该结果与模型预测值基本符合。实验结果对以植物油、高酸值餐饮废弃油脂等为原料制备生物柴油提供了一定的理论基础与实践经验。     

鸡油制备生物柴油的研究

采用鸡油在催化剂KOH的作用下与甲醇发生酯交换反应制备生物柴油,研究了醇油摩尔比、催化剂用量、反应时间、反应温度对反应产率的影响。实验结果表明:醇油摩尔比为7∶1、KOH质量分数为1.0%、反应时间为50min、反应温度为60℃为最优操作条件。在此条件下生物柴油的收率可达97.0%。制得的生物柴油与我国0#柴油和德国生物柴油的主要性能指标接近。     

花椒籽油乙酯生物柴油的制备

以花椒籽油和乙醇为原料,采用酯交换法制备花椒籽油乙酯生物柴油。采用单因素实验研究了催化剂种类和用量、醇油摩尔比、反应温度、反应时间对生物柴油转化率的影响。依据响应面法中的中心组合设计对酯交换反应制备花椒籽油乙酯生物柴油的工艺条件进行了优化。结果表明,花椒籽油乙酯生物柴油制备的最优工艺条件为:以乙醇钠为催化剂,催化剂用量1. 7%,醇油摩尔比11. 5∶1,反应时间120 min,反应温度73℃。在最优条件下,生物柴油转化率达到97. 95%。     

双低油菜籽制备生物柴油的工艺研究

以双低油菜籽为原料,在索氏提取器中加入甲醇和油脂萃取剂混合液来实现菜籽油的提取和酯交换制备生物柴油。试验中考察了5种不同溶剂的浸提效果,以及反应时间、反应温度、醇油摩尔比和催化剂浓度对生物柴油得率的影响。结果表明环己烷为最佳浸提溶剂,得出最佳工艺条件为:醇油摩尔比6∶1,催化剂浓度0.8%,反应时间30 min,反应温度70℃。     

双核酸性离子液体催化餐饮废油制备生物柴油的研究

合成了5种新型咪唑类和吡啶类双核酸性离子液体,并考察了其催化餐饮废油酯交换制备生物柴油的性能。实验表明,咪唑类双核酸性离子液体具有很好的催化活性,其中[MIM]2C3[HSO4]2催化活性最好。在以[MIM]2C3[HSO4]2为催化剂条件下,通过单因素实验和正交实验考察了醇油摩尔比、反应温度、反应时间和催化剂用量对酯交换反应的影响,并考察了双核酸性离子液体的稳定性。结果表明:在醇油摩尔比45∶1、反应温度170℃、反应时间2 h和催化剂用量为餐饮废油质量8%的条件下,生物柴油产率可达95.8%,并且该双核酸性离子液体的稳定性良好,循环使用6次后其催化活性没有明显降低。     

凹土负载KF/CaO复合固体碱催化废油脂合成生物柴油

采用浸渍法制备了凹土负载KF/CaO复合固体碱催化剂,以XRD、SEM、EDS等手段对催化剂进行了表征,并将其用于催化废油脂与甲醇酯交换制备生物柴油,对反应条件进行了优化。结果表明:KCaF3为该复合固体碱催化剂的主要活性成分;在催化剂用量为废油脂质量的7%、醇油摩尔比9∶1、反应温度65℃的条件下,催化反应1.5 h,制备的生物柴油收率可达97.3%。凹土负载KF/CaO复合固体碱重复使用5次后,相同条件下催化废油脂制备生物柴油的收率仍在80%以上。     

蓖麻油制备生物柴油及其性能研究

本文对蓖麻油酯交换制备生物柴油的工艺进行了研究,得出在醇油摩尔比为6∶1,反应时间为6h,反应温度为45℃,催化剂用量为蓖麻油重的0.8%的条件下,生物柴油的产率可达到96%.通过与矿物柴油理化性能指标的比较,生物柴油的多项指标均优于矿物柴油.     

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