3种油脂在煎炸过程中维生素E组分及理化指标变化研究

研究了葵花籽油、菜籽油、花生油在连续煎炸油条过程中维生素E含量及酸值、过氧化值、碘值等理化指标的变化情况。结果表明:3种油脂在32 h煎炸过程中维生素E含量皆随时间的延长而降低,煎炸初始时维生素E总量的排序为菜籽油(48.50 mg/100 g)葵花籽油(32.33 mg/100 g)花生油(19.56 mg/100 g),损失率分别为86.5%、64.9%及95.7%,不同油脂中维生素E的特征组分不同,葵花籽油的特征组分为α-生育酚、α-生育三烯酚和β-生育酚;菜籽油的特征组分为α-生育酚、γ-生育酚和δ-生育酚;花生油的特征组分为α-生育酚、β-生育酚和γ-生育酚;3种油脂的酸值随时间的延长而升高,碘值随时间的延长而降低;葵花籽油和花生油的过氧化值随时间的延长呈现出先升高后降低的趋势,而菜籽油的过氧化值逐渐升高。     

不同食材煎炸过程极性组分与聚甘油酯变化的研究

利用花生油对油条、薯条、豆腐和鸡翅4种食材分别进行间歇性煎炸(每天早、中、晚各煎炸1 h,连续5 d,累计煎炸15 h),通过对所取油样极性组分(PC)与甘油三酯聚合物(TGP)的检测分析表明,不同食材煎炸过程中PC与TGP均呈明显的增加趋势。4种煎炸油脂的PC值从初始的3.34%分别增加至煎炸结束时的20.29%、23.84%、14.67%和26.27%,TGP值从初始的0.43%分别增加至10.86%、15.29%、5.68%和15.75%,增幅顺序均为鸡翅薯条油条豆腐。煎炸结束时,4种油脂中PC含量均未超出我国标准限量(27%),但煎炸油条、薯条和鸡翅油脂中TGP已达到欧盟国家如比利时和捷克规定≤10%的限量。此外,不同食材煎炸油的PC与TGP均存在着极显著的相关性,即可根据相关性方程通过PC值快速地判断出TGP的大致含量。     

食用植物油中EU15+1PAHs污染情况及精炼过程对其含量的影响

采用气相色谱-三重四级杆串联质谱法对4种食用植物油(菜籽油、花生油、芝麻油、茶籽油)共150份样品进行欧盟优控的15+1种多环芳烃(PAHs)检测,分析比较不同油种和不同级别油的污染情况,并对稻米油的精炼过程的样品检测,分析探讨食用植物油中PAHs污染的关键环节,为科学合理提出控制其健康风险的管理措施提供依据。结果显示:我国市售食用植物油不同程度地受到PAHs的污染,检出率在5%~90%之间,平均污染水平范围0.30~4.72μg/kg;PAH4为主要污染物,平均含量12.50μg/kg,其中污染最为严重,检出率90%,平均含量4.72μg/kg;苯并(a)芘作为食用植物油的重要卫生指标,平均含量2.27μg/kg;4种食用植物油中花生油污染最为严重;稻米油精炼过程中脱酸和脱色工序显著降低了PAH4的含量,成品油苯并(a)芘含量小于2μg/kg,∑PAH4含量小于10μg/kg,达到了良好的品质。     

焙炒条件对油菜籽中多环芳烃含量影响的研究

对油菜籽进行不同条件的焙炒,检测其中多环芳烃(PAHs)含量的变化,研究浓香菜籽油生产中焙炒条件对PAHs含量的影响。结果表明:随着焙炒温度升高(160、180、200、220、240、260℃)和焙炒时间延长(10、20、30、40、50、60 min),油菜籽中PAHs含量呈明显的上升趋势;在40 min的焙炒时间内,随温度升高,苯并[a]芘(BaP)、4种多环芳烃(PAH4)、16种多环芳烃(PAH16)含量增幅的差异不显著,超过40 min之后,含量增幅的差异性突显;在260℃、60 min的极限试验条件下,油菜籽中BaP、PAH4、PAH16含量分别从0.15、5.80、30.89μg/kg增加至3.53、21.95、186.75μg/kg;采用160℃、30 min的焙炒条件,油菜籽中BaP、PAH4、PAH16含量分别增加至0.78、8.30、70.58μg/kg,BaP和PAH4含量均未超出欧盟限量(2μg/kg和10μg/kg),同时菜籽油也呈现较好的香味;此外,焙炒过程轻质多环芳烃(LPAHs)含量增幅远大于重质多环芳烃(HPAHs)。     

煎炸油中极性组分与多环芳烃相关性研究

对大豆油、棕榈油及米糠油分别进行连续的油条煎炸操作,研究煎炸时间对油脂中多环芳烃(PAHs)和极性组分(PC)的影响,并探讨PAHs与PC之间的相关性。结果表明:随着煎炸时间延长,3种油脂中的苯并(a)芘(BaP)、PAH4、PAH16和PC含量都呈现出明显的上升趋势;煎炸油中PC的增量与PAHs的增量间存在着极显著的关系:大豆油中Ba P、PAH4、PAH16与PC间的判定系数R2分别为0.953 7、0.949 7、0.968 8;棕榈油中Ba P、PAH4、PAH16与PC间的判定系数R~2分别为0.776 0、0.752 7、0.978 6;米糠油中BaP、PAH4、PAH16与PC间的判定系数R2分别为0.757 4、0.860 4、0.955 6。因此,可根据PC的含量快速预测PAHs的含量,简化检测过程的同时亦能多方面比较油脂中有害物质存在情况,从而为选择最适煎炸油废弃时间提供依据。为了确保煎炸油脂的安全性,避免长时间的高温煎炸至关重要。     

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。     

煎炸不同食材的花生油中极性组分与氧化甘三酯聚合物含量的相关性研究

利用花生油分别对油条、薯条、鸡翅、豆腐4种食材进行32 h连续煎炸,对每隔2 h所取煎炸油样进行极性组分、氧化甘三酯聚合物含量的检测,并与不加任何食材的空白煎炸油脂进行对比,分析研究花生油连续煎炸不同食材过程中极性组分、氧化甘三酯聚合物及其他指标的综合变化。结果表明:随煎炸时间的延长,煎炸油中极性组分、氧化甘三酯聚合物含量升高,煎炸油酸值升高、色泽加深,反式脂肪酸含量升高,经32 h连续深度煎炸,油条、薯条、鸡翅、豆腐、空白5种煎炸油中极性组分从初始的3.34%分别增至32.98%、30.61%、15.50%、29%、47.02%,其中油条、薯条、鸡翅、空白煎炸油中极性组分含量分别在32、24、30、16 h时超出27%的国标限量。氧化甘油三酯聚合物含量从初始的0.43%分别增至18.97%、23.68%、6.52%、16.92%、38.83%。煎炸油中极性组分与氧化甘油三酯聚合物含量间存在极显著的线性相关(P0.01),R2分别为0.996 4、0.993 7、0.9972、0.974 0、0.991 2。经32 h连续煎炸,5种煎炸油的酸值从初始的0.17 (mgKOH/g)的分别增至7.15、2.24、2.39、2.75、2.18(mg KOH/g);反式酸含量从初始的0.17%增加至0.34%、0.28%、0.39%、0.38%、3.54%。     

不同油脂对油炸食品中苯并(a)芘含量的影响

以薯条、油条和鸡块为研究对象,探究花生油、大豆油、菜籽油、24°棕榈油、42°棕榈油5种煎炸油对油炸食品中苯并(a)芘含量的影响,以期在今后的油炸烹饪过程中控制油炸食品中苯并(a)芘的含量。采用5种煎炸油176℃油炸薯条(165 s)、油条(150 s)和鸡块(210 s),并用液相色谱法分析不同油脂对油炸食品中苯并(a)芘含量的影响。结果表明:随煎炸批次的增加,不同油脂煎炸食品中苯并(a)芘含量也逐渐增加。花生油煎炸的食品中苯并(a)芘含量最高,薯条为1.64μg/kg,油条为1.73μg/kg,鸡块为1.15μg/kg;42°棕榈油煎炸的食品中苯并(a)芘含量最低,薯条为0.04μg/kg,油条为0.10μg/kg,鸡块为0.05μg/kg。综上所述,42°棕榈油煎炸的食品中苯并(a)芘含量较低,煎炸稳定性较好。     

油脂煎炸过程中多环芳烃含量的变化

对大豆油、米糠油和棕榈油进行油条煎炸试验,之后对不同煎炸时间油脂中多环芳烃含量进行检测分析,研究煎炸时间对油脂中多环芳烃含量的影响。结果表明:随着煎炸时间的延长,3种油脂中Bap、PAH4、PAH16的含量都呈现明显上升趋势。在32 h的煎炸过程中,大豆油Bap、PAH4、PAH16的含量(μg/kg)分别从原油的1.58、6.88、18.73增加至3.93、10.35;56.10,米糠油Bap、PAH4、PAH16的含量分别从原油的2.52、6.50、25.53增加至3.10、10.34、100.71;棕榈油Bap、PAH4、PAH16的含量分别从原油的1.67、8.60、25.23增加至2.26、10.95、59.98。在高温煎炸过程中,多环芳烃各组分含量的增幅是不同的。大豆油中增幅最大的组分是苊,增幅最小的是苯并(b)荧蒽;米糠油中增幅最大的也是苊,增幅最小的是苯并(g,h,i)苝;棕榈油中增幅最大的是芴,增幅最小的是苯并(a)蒽;3种油脂中轻质多环芳烃含量及增幅都要远多于重质多环芳烃。     

棕榈油在面制品煎炸过程中的品质变化

以棕榈油作为煎炸用油,面制品为原料,在连续无添加新油的油炸模拟体系中,探究不同油炸温度和油炸时间对煎炸油中极性组分(PC)含量、酸价(AV)、甘油三酯聚合物(TGP)含量、脂肪酸组分、多环芳烃(PAH4)含量影响及相关性进行研究.结果 表明,随着煎炸时间延长,AV、TGP含量、PAH4含量、PC含量和饱和脂肪酸(SFA...     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press