基于维生素E组成的植物油掺棕榈油鉴别研究

目的 建立基于维生素E组成的植物油掺棕榈油鉴别方法。方法 采用正相高效液相色谱-荧光检测方法测定大豆油、菜籽油、葵花籽油、橄榄油、玉米油、棕榈油等植物油中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚8种维生素E组成,使用主成分分析（principal component analysis, PCA）构建植物油品种识别和掺假油鉴别模型。结果 不同种类植物油中的生育酚和生育三烯酚的组成差异很大,棕榈油中含高水平的生育三烯酚,这成为其区别于其他5种植物油的一个重要特点。结合PCA可以将棕榈油、葵花籽油、大豆油、橄榄油等相互区分开来。采用PCA建立了针对菜籽油、大豆油、橄榄油、葵花籽油、玉米油中掺棕榈油的鉴别模型,当棕榈油掺杂浓度大于等于25%时,模型可准确识别出掺假油。结论 采用正相液相色谱-荧光检测方法测定植物油中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚8种维生素E组成,结合化学计量学法,可实现对常见植物油掺棕榈油的鉴别。     

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。     

常见植物油中8种生育酚和生育三烯酚含量分析

工作采用正相液相色谱法,对13种、共计42个常见植物油样品中α-、β-、γ-、δ-生育酚和α-、β-、γ-、δ-生育三烯酚等8种维生素E组分进行了的测定。该工作对各油种按维生素E总量、生育酚总量、生育三烯酚总量和α-生育酚分别进行了排序,并对多种植物油中维生素E的组成特点进行了分析。     

几种植物油抗氧化物质的测定

不同植物油的氧化稳定性不同,储藏时间也存在很大的差异。植物油中天然抗氧化成分对油脂加工业、食用油的储藏、油脂含量高的食品加工具有重要的意义。本文采用福林酚法测定11种植物油脂中的总多酚。测定结果表明紫苏油和樟树籽油A中含有较高的总多酚(分别1.40mg/g和1.25mg/g),高于其它植物油(0.45～0.86mg/g)。采用高效液相色谱法测定这些植物油的α-生育酚、γ-生育酚、δ-生育酚3种生育酚的含量,测定结果表明:葵花籽油中含有较高的α-生育酚(21.83mg/100g),菜籽油、玉米油、樟树籽A、紫苏油、大豆油以及氢化大豆油中含有较高的γ-生育酚(15.37～42.85mg/100g),樟树籽油B中含有较多的δ-生育酚(15.48mg/100g)。     

食用植物油中生育酚和生育三烯酚检测方法的研究进展

维生素E是食用植物油中天然存在的抗氧化剂,主要包括α-、β-、γ-、δ-生育酚和相应的生育三烯酚等8种化合物。食用植物油中生育酚和生育三烯酚的组成及含量信息不仅可反映食用植物油的品质,还可用于鉴别其真伪。因此,建立食用植物油中生育酚和生育三烯酚的检测方法具有十分重要的意义。本文对食用植物油中生育酚和生育三烯酚检测方法的研究现状进行了综述,重点介绍了溶剂稀释、皂化和固相萃取等样品前处理技术,以及液相色谱、气相色谱和非水毛细管电泳等分析方法在食用植物油中维生素E测定中的应用。     

常见食用植物油中维生素E异构体含量调查研究

通过查阅国内外官方食物成分数据库,同时综合近年来国内对成品食用植物油中不同生育酚和生育三烯酚含量进行分析的文献,建立常见食用植物油维生素E异构体成分表。结果表明:国内外现有数据库中食用植物油种类及其生育酚和生育三烯酚数据均不全,且不同地区含量存在明显差异。通过对国内最新研究汇总,共收集22种合计659个常见食用植物油的α-、β-、γ-、δ-生育酚数据,同时收集17种合计183个食用植物油的α-、(β+γ)-、δ-生育三烯酚数据。生育酚广泛存在于植物油中,以α-生育酚和γ-生育酚为主,但不同植物油中含量情况存在明显差异;生育三烯酚主要存在于棕榈油、米糠油和葡萄籽油中,在其他植物油中分布很少。不同类型食用植物油的选择会明显影响人体活性VE总量和不同异构体的摄入情况,目前国内外食用植物油VE异构体数据库有地区差异且均不能覆盖目前常见的食用植物油种类,更新常见成品食用植物油VE数据库很有必要。     

7种食用植物油物性及氧化稳定性评价

对国内7种食用植物油的脂肪酸组成、总酚、生育酚、植物甾醇、苯并(a)芘、黄曲霉毒素B1、3-氯丙醇酯含量、氧化稳定性指数(OSI)等指标进行测定分析。结果表明:这7种食用植物油不饱和脂肪酸含量均较高(78.29%~91.92%),但不同油的脂肪酸组成比例各不相同,不饱和脂肪酸、其中单不饱和脂肪酸、多不饱和脂肪酸含量最高的分别为菜籽油(91.92%)、油茶籽油(80.44%)和葵花籽油(61.18%);微量活性成分中,菜籽油的总酚含量最高,为139.83 mg/kg;大豆油、菜籽油、玉米油中γ-生育酚含量较高,葵花籽油、米糠油中α-生育酚含量较高,大豆油生育酚含量最高,为1 129.21 mg/kg;不同油中植物甾醇均以β-谷甾醇为主,米糠油、玉米油中植物甾醇含量较高,分别为10 705.8 mg/kg和8 596.7 mg/kg;危害因子中,只有少数食用植物油检出苯并(a)芘和黄曲霉毒素B1,且含量均符合国家相关标准规定;菜籽油、葵花籽油、大豆油、花生油中3-氯丙醇酯总量较低,均小于1.0 mg/kg;菜籽油、大豆油的氧化稳定性指数(OSI)较高,葵花籽油、油茶籽油的较低,且与总酚含量呈极显著正相关。     

不同原料产地大豆油中维生素E含量的研究

<正>维生素E是一种脂溶性的维生素,易溶于脂肪和乙醇等有机溶剂,不溶于水,在空气中会缓慢氧化,紫外线照射可使其分解[1]。维生素E共有8种组分,包括4种生育酚(α-、 β-、 γ-、 δ-生育酚)和4种生育三烯酚(α-、 β-、 γ-、 δ-生育三烯酚)。研究表明,维生素E在抗氧化、抑制胆固醇合成及肿瘤细胞生长、改善动脉粥样硬化及预防心血管疾病等方面具有优越的生理功能[2-4]。大豆油是市场销售油品中维生素E含量较高的植物油,     

4种油脂煎炸过程中维生素E组分含量变化的研究

用米糠油、大豆油、棕榈油、米糠调和油进行连续煎炸油条试验,通过对不同煎炸时间所取油样中维生素E各组分含量及酸值、羰基价、极性组分含量的检测,分析研究这4种油脂在煎炸过程中维生素E各组分含量的变化及其对油脂煎炸稳定性的影响。结果表明:4种油脂初始维生素E含量大小依次为大豆油米糠油米糠调和油棕榈油,生育三烯酚含量占维生素E总量大小依次为米糠调和油米糠油棕榈油大豆油;随着煎炸时间延长,4种油脂中维生素E含量均持续快速降低,至煎炸32 h结束时,维生素E损失率为大豆油77.12%、米糠油97.93%、棕榈油100%、米糠调和油93.86%;米糠油虽不如大豆油的维生素E含量高(为大豆油的51.13%),但因富含生育三烯酚(为大豆油的7.2倍),使其极性组分含量及羰基价增幅均小于大豆油,表现出良好的煎炸稳定性。     

8种不同植物油的脂肪酸组成及抗氧化性比较

以紫苏籽油、芝麻油、胡麻油、青花菜籽油、大豆油、花生油、玉米油、葵花籽油8种植物油为研究对象,比较不同种类植物油的脂肪酸组成、多酚含量和抗氧化性。结果表明：8种植物油脂肪酸组成比例各不相同,其中花生油中油酸含量最高,为43.98%,葵花籽油中亚油酸含量最高,为6500%,紫苏籽油中亚麻酸含量最高,为63.89%;8种植物油的DPPH自由基清除能力强弱顺序为芝麻油>大豆油>玉米油>青花菜籽油>胡麻油>花生油>紫苏籽油>葵花籽油,与其多酚含量一致;8种植物油的铁离子还原能力从大到小依次为芝麻油＞大豆油＞青花菜籽油＞花生油＞胡麻油＞玉米油＞紫苏籽油＞葵花籽油。     

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.     

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.     

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.     

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.     

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.     

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.     

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.