脱臭过程对玉米油中反式脂肪酸含量的影响

研究了脱臭过程中脱臭温度、脱臭时间和脱臭塔残压对玉米油中反式脂肪酸含量的影响,从而确定最佳脱臭工艺条件,尽量减少玉米油精炼过程中反式脂肪酸的生成。     

玉米油脱臭条件对3-氯丙醇酯和缩水甘油酯影响的研究

以玉米油为原料,研究水蒸气蒸馏脱臭过程以及脱臭条件对玉米油中3-氯丙醇酯和缩水甘油酯生成的影响。结果表明:脱臭过程造成3-氯丙醇酯和缩水甘油酯含量的大幅升高,脱臭温度越高、脱臭时间越长,3-氯丙醇酯和缩水甘油酯的增加量越大,其中脱臭温度比脱臭时间对二者生成的影响更大;在脱臭温度不超过230℃时,60~120 min的脱臭时间,3-氯丙醇酯含量仅增加了0.047~2.581 mg/kg,缩水甘油酯含量仅增加了0.300~3.883 mg/kg,当脱臭温度达到250℃时,即使脱臭时间仅为60 min,3-氯丙醇酯和缩水甘油酯含量均显著升高了5.039 mg/kg和8.354mg/kg,尤其在270℃、120 min的极限脱臭条件下,3-氯丙醇酯和缩水甘油酯含量更是分别上升至13.004 mg/kg和34.864 mg/kg,达到待脱臭玉米油中其含量的4倍和15倍左右。为防范和控制玉米油脱臭过程3-氯丙醇酯和缩水甘油酯的生成,降低脱臭温度是非常必要的。     

脱臭工艺和脱臭条件对菜籽油综合品质的影响

对菜籽油进行不同温度(210℃、230℃、250℃、270℃)、不同时间(60 min、80 min、100 min、100 min)的常规脱臭及双温脱臭(190℃/50 min+230℃、240℃、250℃、260℃、270℃/30 min),检测脱臭前后菜籽油中多环芳烃(PAHs)、3-氯丙醇酯(3-MCPD酯)、缩水甘油酯(GEs)、维生素E、植物甾醇、反式脂肪酸含量,分析研究不同脱臭工艺和脱臭条件对菜籽油综合品质的影响。结果表明：在常规脱臭工艺中,随脱臭温度升高和脱臭时间延长,PAHs脱除率提高,苯并芘(BaP)脱除率10.04%~45.08%;在适度脱臭条件下(230℃、60~120min),3-MCPD酯含量升幅均在0.3 mg/kg之内(从0.5升高至0.73 mg/kg),GEs含量升幅均在0.9 mg/kg之内(从1.19升高至2.04 mg/kg);230℃/60 min维生素E损失率为13.09%,230℃/120 min甾醇损失率15.86%,反式脂肪酸含量升高0.51%。采用190℃/50 min+260℃/30 min的双温脱臭工艺,BaP脱除率为36%;190℃/50 min+230℃/30 min双温脱臭后,3-MCPD酯和GEs含量为0.74、0.87 mg/kg,维生素E和甾醇损失率分别为7.20%、3.47%,未有反式酸生成。与单温脱臭工艺相比,双温脱臭对提升菜籽油综合品质有明显优势。     

降低大豆油精炼过程反式脂肪酸含量研究

研究精炼过程对大豆油反式脂肪酸含量变化,发现在碱炼、脱色工段反式脂肪酸含量没明显变化,而在脱臭工段反式脂肪酸含量发生显著变化,表明精炼时脱臭是产生反式脂肪酸主要阶段;同时比较脱臭温度,脱臭塔结构,脱臭时间对大豆油反式脂肪酸形成影响,并根据研究结果,提出工业化降低大豆油反式脂肪酸可行性工艺。     

脱臭工艺条件对米糠油中反式脂肪酸含量的影响

研究了脱臭温度和脱臭时间对米糠油中反式脂肪酸含量的影响。结果表明,脱臭温度和脱臭时间对米糠油中反式油酸含量的影响很小;脱臭温度对米糠油中反式亚油酸含量影响显著,脱臭时间对其影响的显著性次之;在一定的脱臭时间下,不同脱臭温度下米糠油中总反式脂肪酸含量最多的约为最少的30-40倍,在250℃以下米糠油中总反式脂肪酸的形成速度缓慢、相对含量低;在一定的脱臭温度下,不同脱臭时间时米糠油中总反式脂肪酸含量最多约为最少的8倍,且在250℃和270℃时,脱臭时间在40 min以下米糠油中总反式脂肪酸的形成速度缓慢、相对含量低。     

不同脱臭工艺和条件对菜籽油综合品质的影响

为研究脱臭工艺和脱臭条件对菜籽油综合品质的影响,对菜籽油分别进行不同温度(210、230、250、270℃)、不同时间(60、80、100、120 min)的常规脱臭及双温脱臭(低温阶段190℃,50 min,高温阶段230、240、250、260、270℃,30 min),检测脱臭前后菜籽油中多环芳烃(PAHs)、3-氯丙醇酯(3-MCPD酯)、缩水甘油酯(GEs)、维生素E、植物甾醇、反式脂肪酸含量,分析研究不同脱臭工艺和脱臭条件对菜籽油综合品质的影响。结果表明:在常规脱臭工艺中,随脱臭温度升高和脱臭时间延长,PAHs脱除率提高,苯并芘(BaP)脱除率10.04%～45.08%;在适度脱臭条件下(230℃、60～120min),3-MCPD酯含量升幅均在0.3 mg/kg之内(从0.5升高至0.73 mg/kg),GEs含量升幅均在0.9 mg/kg之内(从1.19升高至2.04 mg/kg);230℃/60 min维生素E损失率为13.09%,230℃/120 min甾醇损失率15.86%,反式脂肪酸含量升高0.51%。采用190℃/50 min+260℃/30 min的双温脱臭工艺,BaP脱除率为36%;190℃/50 min+230℃/30 min双温脱臭后,3-MCPD酯和GEs含量分别为0.74、0.87 mg/kg,维生素E和甾醇损失率分别为7.20%、3.47%,未有反式酸生成。与单温脱臭工艺相比,双温脱臭对提升菜籽油综合品质有明显优势。     

脱臭工艺条件对花生油中反式脂肪酸含量的影响

研究了脱臭温度和脱臭时间对花生油中反式脂肪酸含量的影响。结果表明:脱臭温度和脱臭时间对花生油中反式油酸含量的影响很小;脱臭温度对花生油中反式亚油酸含量影响显著,脱臭时间对其影响的显著性次之;在脱臭温度255℃以下和脱臭时间40 min以下花生油中总反式脂肪酸的形成速度缓慢,相对含量低;在脱臭温度255℃以上和脱臭时间40 min以上花生油中总反式脂肪酸的形成速度快,相对含量高,其最高含量为4.081%。     

脱臭工艺条件对猪油中反式脂肪酸含量的影响

研究了脱臭温度和脱臭时间对猪油中反式脂肪酸含量的影响.结果表明:脱臭温度和脱臭时间对猪油中反式油酸含量的影响相对较小;脱臭温度对猪油中反式亚油酸含量影响相对显著,脱臭时间对其影响的显著性次之;在脱臭温度250℃以下和脱臭时间40 min以下猪油中总反式脂肪酸的形成速度缓慢、相对含量低;在脱臭温度250℃以上和脱臭时间40 min以上猪油中总反式脂肪酸的形成速度快、相对含量高,其最高含量为1.238%.     

脱臭工艺条件对棕榈油中反式脂肪酸含量的影响

研究了脱臭温度和脱臭时间对棕榈油中反式脂肪酸含量的影响.结果表明:脱臭温度和脱臭时间对棕榈油中反式油酸含量的影响很小;脱臭温度对棕榈油中反式亚油酸含量影响显著,脱臭时间对其影响的显著性次之;在脱臭温度255℃以下和脱臭时间40 min以下棕榈油中总反式脂肪酸的形成速度缓慢,相对含量低;在脱臭温度255℃以上和脱臭时间40 min以上棕榈油中总反式脂肪酸的形成速度快,但生成量相对较少,其最高含量为0.637％.     

脱臭工艺条件对牡丹籽油反式脂肪酸形成及品质的影响

以牡丹籽毛油为原料,经过水化脱胶、碱炼脱酸和吸附脱色后,于160、190、250℃和270℃下脱臭处理,气相色谱法分析不同脱臭时间下牡丹籽油反式脂肪酸含量变化,考察各脂肪酸的反化率,同时检测其酸值、过氧化值、色泽和气味指标变化。结果表明:脱臭温度对牡丹籽油反式脂肪酸含量影响最显著,脱臭时间次之,即脱臭温度越高、脱臭时间越长反式脂肪酸含量越多;就脂肪酸反化率而言,亚麻酸亚油酸油酸;且反式脂肪酸的形成没有位置选择性,即Sn-1,3与Sn-2位的不饱和脂肪酸的反化率相似;牡丹籽油适合的脱臭温度为190℃、脱臭时间为60 min,在此条件下得到的脱臭牡丹籽油总反式脂肪酸含量小于1%,所测定品质指标均符合二级大豆油国家标准。     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.     

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%.