天然维生素E油中PAH4连续脱除工艺研究北大核心CSCD

建立了一种天然维生素E油连续通过颗粒活性炭的固定床吸附工艺,从而实现有效脱除其中含有的微量多环芳烃(PAHs)。通过单因素实验分别考察了料液比、体系温度、物料在填料中的吸附时间对PAH4(苯并(a)芘、苯并(a)蒽、苯并(b)荧蒽、䓛)脱除效果的影响,并通过正交实验进行了工艺条件优化。同时,考察了PAH4脱除过程对天然维生素E含量的影响。结果表明:以95%乙醇为溶剂,料液比(天然维生素E油与溶剂比)1∶3,体系温度40℃,在以颗粒活性炭为填料的固定床内吸附4 h的条件下,可使天然维生素E油中PAH4的残留量降至7.3μg/kg(其中苯并(a)芘含量为1.8μg/kg),符合欧盟标准要求的苯并(a)芘含量小于或等于2μg/kg,PAH4含量小于或等于10μg/kg的限量标准,且采用该PAH4脱除工艺后维生素E的含量没有受到明显影响。     

吸附法脱除油脂中多环芳烃的效果研究

以花生油为原料,以吸附剂种类、吸附剂用量、吸附温度和吸附时间为单因素试验考察因素,通过单因素试验和正交试验研究吸附法对油脂中多环芳烃的脱除效果及最佳脱除条件。结果表明,不同种类吸附剂对花生油中多环芳烃的脱除效果依次为:Norit-8015活性炭WY2号活性炭WY1号活性炭Kermel活性炭活性白土凹凸棒土。综合考虑对花生油中B(a)P、HPAHs、PAH4、LPAHs和PAH16的脱除率以及对花生油香味的保留和生产成本,优化的脱除条件为:WY2号活性炭用量1.0%,吸附时间35min,吸附温度110℃。在此条件下,花生油中B(a)P、HPAHs、PAH4、LPAHs及PAH16的残留量分别为0.06、0.69、1.74、95.11μg/kg及80.90μg/kg,脱除率分别为99.74%、99.28%、98.65%、85.75%及89.41%,若仅考虑B(a)P、PAH4的残留量达到欧盟标准(分别为≤2μg/kg和≤10μg/kg),WY2号活性炭的添加量为0.5%就可满足要求,此时B(a)P和PAH4的残留量分别为0.53μg/kg和6.64μg/kg,脱除率分别为97.79%和94.86%。     

葵花籽油中多环芳烃及色泽的吸附脱除研究

利用混合吸附剂对葵花籽油中16种多环芳烃(PAH16)及色泽进行吸附脱除。通过单因素试验考察了活性白土、活性炭、混合吸附剂用量、吸附温度、吸附时间对葵花籽油中PAH16及色泽脱除效果的影响,并采用正交试验对吸附脱除条件进行了优化。结果显示,在混合吸附剂用量为活性白土3%+活性炭1%、吸附温度110℃、吸附时间35 min的最优条件下,葵花籽油中BaP(苯并[a]芘)、PAH4(欧盟限定的4种多环芳烃)、HPAHs(6种重质多环芳烃)、LPAHs(10种轻质多环芳烃)、PAH16的脱除率分别为99.88%、95.49%、97.63%、83.63%、85.71%,残留量分别为0.02、2.09、0.83、42.18、43.01μg/kg,BaP和PAH4残留量达到并明显优于出口欧盟的要求,同时油脂脱色率为79.43%,达到了一级油的色泽指标。     

GC-MS法测定多种食用油中的多环芳烃

多环芳烃是一类常见的环境有机污染物,随着人们对其毒性研究逐步深入,各国相继制定限量要求。随机选取市面上不同种类的食用油,采用GC-MS法进行多环芳烃的测定,评估其食品安全风险。结果表明, 15种食用油中苯并[a]芘含量在0.00～9.20μg/kg之间,苯并[a]芘、苯并[a]蒽、苯并[b]荧蒽和苯并菲的含量之和在0.00～28.74μg/kg之间, 16种多环芳烃总量在0.00～72.47μg/kg之间。对随机网上购买食品安全风险较高的10份芝麻油进行测定,苯并[a]芘含量在0.00～6.76μg/kg之间,苯并[a]芘、苯并[a]蒽、苯并[b]荧蒽和苯并菲的总量在0.00～9.64μg/kg之间,16种多环芳烃总量在0.00～16.18μg/kg之间。植物油中多环芳烃含量水平相差较大,部分存在一定的食品安全风险,出口企业还应关注苯并[a]芘、苯并[a]蒽、苯并[b]荧蒽和苯并菲含量的水平。     

大豆油精炼过程中多环芳烃的迁移规律

明确大豆油精炼过程多环芳烃（polycyclic aromatic hydrocarbons,PAHs）风险成分的迁移规律,以便于食品中PAHs的风险防范和控制。通过对大豆油精炼生产中脱胶油、脱酸油、脱色油、脱臭油和对应加工助剂磷酸、烧碱、活性白土以及精炼副产物油脚、皂脚、废白土、脱臭馏出物样品中PAHs组分含量的检测,分析PAHs在大豆油精炼生产中的迁移规律。结果显示：大豆油精炼用加工助剂中均含有PAHs,磷酸、烧碱和活性白土中苯并[a]芘（benzo[a]pyrene,BaP）含量分别为0.95、1.84?μg/kg和0.71?μg/kg,欧盟限量控制的4?种PAHs（PAH4）（苯并[a]蒽、?、苯并[b]荧蒽和BaP）含量为2.81、16.81?μg/kg和8.85?μg/kg,美国优先控制的16?种PAHs（PAH16）含量为26.18、112.61?μg/kg和111.85?μg/kg;在大豆油水化脱胶、碱炼脱酸、蒸馏脱臭过程BaP的脱除率分别为7.57%、23.57%、91.65%,水化脱胶、碱炼脱酸、吸附脱色、蒸馏脱臭过程PAH4的脱除率分别为15.93%、10.41%、19.31%、50.91%,PAH16的脱除率分别为15.45%、11.59%、6.66%、52.99%;大豆油精炼副产物油脚、皂脚、废白土、脱臭馏出物中BaP含量分别为0.45、0.90、0.52、12.49?μg/kg,PAH4含量分别为10.14、7.39、9.69、300.50?μg/kg,PAH16含量分别为261.60、434.49、156.29、2?775.15?μg/kg。     

液相色谱-串联质谱法检测食用油脂中多环芳烃

建立了有机溶剂萃取、硅胶固相萃取柱净化、液相色谱-串联质谱法(LC-MS/MS法)测定食用油脂中EPA 16种多环芳烃的检测方法。EPA 16种多环芳烃的定量限分别为0.02~0.43μg/kg,回收率为86.5%~104.6%,日内精密度小于6%,日间精密度小于5%。在40个受测油脂样品中,EPA 16种多环芳烃的含量范围为11.68~146.06μg/kg。对照我国GB 2716规定,所有受测样品中苯并(a)芘含量均不超过≤10μg/kg的限量标准。然而,8个油样的苯并(a)芘含量超过了欧盟≤2μg/kg的限量标准,10个油样的PAH4含量超过了欧盟≤10μg/kg的限量标准。     

冷冻除脂-气相色谱-串联质谱法检测食用植物油中30 种多环芳烃

建立冷冻除脂--气相色谱-串联质谱检测食用植物油中30?种多环芳烃（polycyclic aromatic hydrocarbons,PAH）的方法。选用6?种氘标记PAH为内标,样品经乙腈--丙酮溶液（4∶1,V/V）于离心管中涡旋提取,10?000?r/min离心5?min,－80?℃对油脂冷冻固化,倾出提取液,再经减压浓缩和氮气吹干,以二氯甲烷复溶,气相色谱--串联质谱多反应监测方式进行检测。结果表明,在相应质量浓度范围内30?种PAH均有良好线性（R2＞0.998）,检出限为0.10～1.83?μg/kg,定量限为0.35～6.11?μg/kg,在5、20?μg/kg和50?μg/kg添加水平下的回收率为67.77%～119.28%,相对标准偏差为1.18%～12.47%。采用本方法对市售11?类38?个食用植物油样品的检测显示,萘、1-甲基萘、2--甲基萘、联苯、2,6--二甲基萘、苊烯、苊、2,3,6--三甲基萘、芴、二苯并噻吩、菲、蒽、1-甲基菲、荧蒽、芘、环戊烯[c,d]芘、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[e]芘和苯并[a]芘的检出率均为100%;5--甲基屈、苝、茚并[1,2,3--c,d]芘、二苯并[a,h]蒽、苯并[g,h,i]苝和二苯并[a,l]芘的检出率分别为86.84%、63.16%、81.58%、21.05%、81.58%和26.32%;二苯并[a,e]芘和二苯并[a,h]芘未检出;PAH总量为92.56～905.16?μg/kg,其中苯并[a]芘含量为1.94～7.40?μg/kg,依据食品安全标准限量,PAH处于较安全水平。     

玉米油中黄曲霉毒素B_1的吸附脱除效果研究

以玉米油中黄曲霉毒素B_1(AFB_1)脱除率为主要考察指标,研究不同吸附剂、吸附剂添加量以及吸附时间、吸附温度对玉米油中AFB_1的脱除效果和最佳脱除条件。结果表明:当吸附剂添加量为油质量的2%时,活性白土、凹凸棒石、WY1活性炭、WY2活性炭及普通活性炭对玉米毛油中AFB_1的脱除率分别为98.04%、97.66%、94.35%、95.72%和75.71%,AFB_1含量由39.28μg/kg分别降至0.77、0.92、2.22、1.68、9.54μg/kg,明显优于GB 2716—2005《食用植物油卫生标准》中规定的AFB_1含量小于等于20μg/kg的限量指标;在玉米油吸附脱色的精炼过程中,选用活性白土或凹凸棒石或WY2活性炭、添加量2%、吸附时间25 min、吸附温度100℃的工艺条件,可将玉米毛油中AFB_1含量降至欧盟要求的小于等于2μg/kg的限量指标;若综合考虑AFB_1脱除、吸附剂成本及油脂损耗,可适当降低吸附剂添加量,当WY1和WY2活性炭添加量为1%时,可将玉米毛油中AFB_1含量分别降至3.07、2.15μg/kg。     

吸附法脱除花生油中苯并（a）芘的效果研究

为了降低花生油中的苯并（a）芘含量,同时兼顾花生油色泽,采用活性炭和活性白土复合吸附剂对花生油中苯并（a）芘进行吸附脱除,通过单因素实验研究了活性炭种类、复合吸附剂添加量、复合吸附剂配比、吸附温度和吸附时间对花生油中苯并（a）芘脱除效果的影响,并采用正交实验对吸附工艺条件进行优化。结果表明：活性白土和FC1X活性炭复合对花生油中的苯并（a）芘具有最好的脱除效果,最优工艺条件为复合吸附剂添加量2%、活性白土与FC1X活性炭质量比20∶1、吸附时间20 min、吸附温度130℃,在最优条件下花生油中的苯并（a）芘含量降至0.12 μg/kg,远小于欧盟限量2 μg/kg,色泽为Y10、R0.7。复合吸附剂能有效吸附脱除花生油中99%以上的苯并（a）芘,且花生油呈淡黄色、澄清透明,满足企业生产要求。     

气相色谱-质谱法评定紫苏油中多环芳烃类不确定度

目的：为降低紫苏油多环芳烃PAH4检测过程的不确定度,提高实验室检验检测结果的准确性。方法：采用气相色谱-质谱法对紫苏油中多环芳烃PAH4测定含量进行不确定度评定,通过建立数学模型,分析测定过程的主要不确定度来源,评估各个分量。结果：该法中苯并[a]蒽含量测定结果（1.14±0.31）μg/kg,k=2;?含量测定结果为（0.47±0.22）μg/kg,k=2;苯并[b]荧蒽含量测定结果为（4.62±0.79）μg/kg,k=2;苯并[a]芘含量测定结果为（3.90±1.19）μg/kg,k=2。结论：该检测方法影响检测结果不确定度的主要因素为标准物质、校准曲线、气相色谱-质谱联用仪及样品处理,其他因素影响相对较小,在检测过程应加以控制。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.