气相色谱-质谱联用法分析茶枝柑籽油脂肪酸和不皂化物组成

目的研究茶枝柑籽油的脂肪酸和不皂化物成分。方法采用气相色谱-质谱联用(gas chromatographymass spectrometry,GC-MS)法对茶枝柑籽油脂肪酸和不皂化物成分进行分析和鉴定。结果共分离鉴定出13种脂肪酸,不饱和脂肪酸占67.62%,其中最主要的脂肪酸为亚油酸和油酸,相对含量分别为36.93%和26.91%。茶枝柑籽油的不皂化物以植物甾醇、生育酚和萜类化合物为主,其中β-谷甾醇含量最高,达2544.73mg/kg。结论本研究为茶枝柑籽油作为功能性油脂的开发利用提供了基础数据。     

刺槐籽油中脂肪酸组成和不皂化物的GC—MS分析

用正己烷抽提刺槐籽油,样品经皂化和甲酯化后,用气相色谱-质谱联用法（GC—MS）测定了刺槐籽油的脂肪酸和不皂化物组成,共鉴定出7种脂肪酸和15种不皂化物,其中不饱和脂肪酸相对含量较高,主要为亚油酸和亚麻酸,其相对含量分别为62．99％和21．88％。刺槐籽油不皂化物中植物甾醇含量很高,γ-谷甾醇含量达40．33％。     

青藏高原狭果茶藨子籽油成分分析及原油三脱工艺优化

以青海地区狭果茶藨子籽油为研究对象,对其不皂化物及脂肪酸组成进行分析,同时借助单因素及响应面试验对籽油水化脱胶、吸附脱色、吸附脱酸工艺进行优化,并对籽油精炼前后理化指标进行对比,以明确青海地区狭果茶藨子籽油成分及较优的精炼工艺,扩大青海地区狭果茶藨子籽油的开发应用。结果表明,狭果茶藨子籽油中含有植醇、谷甾醇、新植二烯等不皂化物,其中植醇占8.78%;共检测出脂肪酸8种,其中不饱和脂肪酸占88.89%,油酸和亚油酸含量相对较高,分别为37.09%和50.80%。响应面试验结果表明:最佳脱胶工艺条件为水化时间:16 min,磷酸添加量:0.3%,加水量:3.0%,脱胶温度:50 ℃;最佳脱色工艺条件为脱色时间:20 min,脱色剂添加量:7.0%,脱色温度:51 ℃;最佳脱酸工艺条件为脱酸时间:87 min,微晶纤维素添加量:2.0%,脱酸温度:40 ℃;此条件下狭果茶藨子籽油脱胶率、脱色率、脱酸率分别为80.48%、66.48%、71.30%。精炼后,狭果茶藨子籽油的酸价和光密度下降较大,碘值和皂化值也有轻微下降,过氧化值轻微上升,精炼前后所有指标测定值均在国标范围内浮动,说明此精炼工艺对油脂营养价值产生一定影响,但能提升狭果茶藨子籽油的感官品质,有利于油脂贮藏,可用于狭果茶藨子籽油的精制。     

樟树籽油抗氧化能力及物质基础研究

植物油中天然抗氧化成分对油脂的加工、货架期及营养品质具有重要影响。为研究樟树籽油抗氧化活性及物质基础,本文分别对其脂肪酸组成、不皂化物含量、总酚含量和DPPH自由基清除率进行测定,分析总多酚及不皂化物对樟树籽油抗氧化活性的贡献率,明确樟树籽油抗氧化活性物质基础。结果表明,樟树籽油中主要为中链脂肪酸癸酸和月桂酸,二者含量占总脂肪酸的94.80%,不皂化物含量为0.55±0.01% ,总多酚含量为33.07 ±0.63 mg.kg_^-1。樟树籽油对DPPH自由基清除率的IC₅₀值为0.13 g.mL_^-1。相同质量浓度的樟树籽油、不皂化物和总多酚对DPPH自由基清除率分别为98.92±1.58%、38.49±0.66%、49.60±3.78%。因此,不皂化物及总酚对樟树籽油抗氧化贡献率分别为38.91%、50.14%。研究结果表明樟树籽油具有较强的抗氧化能力,其抗氧化活性物质主要为多酚类成分和不皂化物,二者对樟树籽油抗氧化能力的总贡献率高达89.05%。本研究初步明确了樟树籽油的抗氧化活性成分,可为樟树籽油的开发利用奠定基础。     

番茄籽油不皂化物成分分析与分离

采用GC-MS分析番茄籽油不皂化物成分,并通过薄层层析(TLC)对不皂化物进行初步分离。通过GC-MS从番茄籽油不皂化物中分离出42个峰,鉴定出29种物质,主要成分为β-谷甾醇、胆甾醇、豆甾醇、环菠萝烷醇、羊毛甾醇、γ-生育酚、(3β,5α)-胆甾-7-烯-3-醇、γ-谷甾醇、麦角甾醇、二十九烷、角鲨烯,其中β-谷甾醇含量最高,为15.68%;以正己烷与氯仿(7:3,V/V)为展开剂,通过TLC分离番茄籽油不皂化物,得到6条色带,利用紫外-可见光对分离物进行扫描,6种分离物最大吸收峰均不相同。     

冬枣核油的营养成分和抗氧化能力分析

对冬枣核油的脂肪酸组成和营养成分进行分析,并测定了其中极性成分与非极性成分的抗氧化能力。结果表明:冬枣核油含有11种脂肪酸,不饱和脂肪酸含量为74. 79%,其中油酸与亚油酸的含量较均衡,分别为39. 34%和33. 74%;冬枣核油中含有14种不皂化物,其中含有在普通植物油中不常见的γ-谷甾醇,占总不皂化物的53. 11%;冬枣核油中共检出3种生育酚和2种生育三烯酚,其中γ-生育酚含量(106. 34 mg/kg)最高,其次为α-生育酚(31. 48 mg/kg);冬枣核油中非极性成分抗氧化能力高于极性成分,其清除DPPH自由基和ABTS自由基的能力分别为114. 95mgTE/kg和207. 8 mgTE/kg。     

马蔺籽油的索氏提取工艺、成分分析及抗氧化活性研究

以石油醚为提取溶剂,选取提取时间、提取温度、料液比作为考察因素,在单因素实验的基础上,以马蔺籽油得率为响应值,进行响应面优化实验以确定马蔺籽油最佳提取工艺条件。对马蔺籽油的理化性质、脂肪酸组成及不皂化物成分进行分析,同时研究了马蔺籽油的抗氧化活性。结果表明,马蔺籽油索氏提取最佳工艺条件为提取时间6 h、提取温度70 ℃、料液比1∶ 26。在最佳条件下,马蔺籽油得率达到11.20%。马蔺籽油在265 nm处的吸光度为4.667,呈现黄色透明状。马蔺籽油不皂化物含量1.37%,皂化值(KOH)185.2 mg/g,酸价（KOH）0.038 mg/g,碘值（I）113.7 g/100 g,过氧化值5.159 mmol/kg。GC-MS分析结果显示,马蔺籽油不饱和脂肪酸含量为8471%,脂肪酸组成主要为亚油酸（45.32%）、油酸（38.42%）、棕榈酸（6.88%）及硬脂酸（238%）。不皂化物中甾醇类化合物总含量高达66.19%,其中β-谷甾醇725.87 mg/kg、菜油甾醇410.50 mg/kg、豆甾醇1 231.55 mg/kg,另外还含有高浓度的抗氧化剂豆甾-5,24(28)-二烯-3β-醇。马蔺籽油具有良好的抗氧化活性,DPPH自由基清除率IC50值为19.86 mg/mL,FRAP法测定其在质量浓度为280 mg/mL时总抗氧化能力为0.202 4 mmol/L。     

香榧籽油的脂肪酸及不皂化物组成分析

香榧为我国特产的名贵干果,试验对其籽油的脂肪酸及不皂化物采用GC/MS进行了定性定量分析,结果确定香榧籽油脂肪酸组成以亚油酸与油酸为主,质量分数分别为39.60%与35.40%,其次为棕榈酸(10.24%)。一种特殊脂肪酸,金松酸(顺5,11,14-二十碳三烯酸),质量分数达8.65%。另外,香榧籽油的不皂化物组成以β-谷甾醇和β-生育酚为主,含量分别为1.10 mg/g和0.51 mg/g。本研究为香榧籽油作为高档功能性油脂的开发利用提供了基础数据。     

苦瓜籽油脂肪酸成分的GC-MS分析

利用索氏抽提法提取苦瓜籽油,对苦瓜籽油的碘值、皂化值、不皂化物、熔点等理化性质进行了测定,并用氢氧化钾-甲醇室温酯化法对苦瓜籽油甲酯化,通过GC-MS对其脂肪酸成分进行分析.结果表明,苦瓜籽脂肪含量(36.81%)和蛋白含量(43.05%)都较高,苦瓜籽油常温下呈蜡状白色固体,同时有特殊的刺鼻苦涩气味.熔点为53℃,不...     

省沽油种仁油脂肪酸及不皂化物分析

采用GC-MS分析省沽油种仁油中脂肪酸和不皂化物的组成与含量。结果表明:省沽油种仁油中不饱和脂肪酸含量达86.68%,主要为油酸、亚油酸和亚麻酸;油中不皂化物共鉴定出6种植物甾醇、3种烯烃、1种维生素和12种烷烃类化合物,其中γ-谷甾醇、角鲨烯和维生素E含量最高,分别为411.21、257.72 mg/kg和151.94 mg/kg,经质谱离子碎片对比分析,省沽油种仁油中的维生素E为α-生育酚。     

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.     

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.     

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.     

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.