新型婴儿配方乳粉脂肪酸母乳化研究

通过参考母乳营养成分及脂肪酸模式、国家标准及中国居民膳食营养素参考摄入量,进行新型婴儿配方奶粉的设计和生产;通过选用玉米油、大豆油和棕榈油进行油脂的复配,在满足婴儿配方乳粉脂肪质量分数的同时,从脂肪酸的角度上模拟母乳,使饱和与不饱和脂肪酸、亚油酸与亚麻酸的质量分数及比例更加接近母乳。应用气相色谱-质谱联机对制得的新型婴儿配方乳粉进行脂肪酸组分的分析,并使用毛细管气相色谱法测定样品中的亚油酸质量分数,以检验饱和脂肪酸与不饱和脂肪酸的比例,以及亚油酸与亚麻酸的质量分数和比例。最后确定了添加油脂比例为:大豆油6.0%,玉米油7.0%,棕榈油1.20%;不饱和脂肪酸占总脂肪酸质量分数的59.352%,饱和脂肪酸占总脂肪酸质量分数的40.649%,不饱和脂肪酸与饱和脂肪酸的比例为1.4601,符合资料报道的1~1.5∶1的理想比例,亚油酸与亚麻酸的比值为10.2865,符合8~11∶1的理想比例,亚油酸质量分数为24.60 mg/g。     

气相色谱-质谱联用法测定植物油中脂肪酸组成

建立气相色谱-质谱联用法测定植物油中脂肪酸组成的方法。选用硼化氟-甲醇体系对样品进行甲酯化处理,再通过气相色谱-质谱技术对脂肪酸组成进行分析和鉴定。共分离出11种脂肪酸,结果表明:植物油中的脂肪酸以油酸、亚油酸、棕榈酸、硬脂酸为主,其中油酸和亚油酸含量均达70%以上,不饱和脂肪酸含量与饱和脂肪酸含量的比值:玉米油5.9%,菜籽油17.6%,葵花籽油11.7%,花生油3%,调和油5%。植物油中不饱和脂肪酸含量远远高于饱和脂肪酸含量。     

几种常用植物油在婴儿配方乳粉中的应用研究

以几种常用植物油为主要研究对象,对植物油和牛乳脂肪的脂肪酸组成进行检测。依据国标对婴儿配方乳粉中脂肪含量的规定并参考母乳脂肪含量,对牛乳脂肪和植物油中的油酸、亚油酸、亚油酸与α-亚麻酸的比值、饱和脂肪酸的含量等进行了详细分析。根据这些脂肪酸的特点将植物油进行了分类,从脂肪酸含量入手对几种常用植物油在婴儿配方乳粉中的应用进行了研究。     

10种小宗植物油的脂肪酸组成及氧化稳定性

考察山茶籽油、乳木果油、亚麻籽油、牡丹籽油、核桃油、葡萄籽油、玫瑰果油、紫苏籽油、石榴籽油和甜杏仁油10种植物油的脂肪酸组成、酸价、过氧化值（POV）、硫代巴比妥酸（TBA）值和油稳定性指数（OSI）。结果显示：10种植物油中,除乳木果油不饱和脂肪酸含量偏低,为50.41%（质量分数）,其余植物油不饱和脂肪酸含量均较高（84.34%~92.47%,质量分数）。亚麻籽油和牡丹籽油的主要脂肪酸为α-亚麻酸,山茶籽油和乳木果油主要脂肪酸含量为油酸＞亚油酸＞α-亚麻酸,剩余6种植物油则为亚油酸＞油酸＞α-亚麻酸。根据酸价,山茶籽油、玫瑰果油与紫苏籽油品质最好,亚麻籽油则相反,新鲜度最低。综合POV和TBA值两个指标,亚麻籽油主要处于深度氧化阶段,核桃油虽已深度氧化但仍主要为初级氧化产物,乳木果油与葡萄籽油更易发生深度氧化,剩余植物油氧化程度不高。乳木果油的OSI最高,核桃油最低,且10种植物油的OSI与多不饱和脂肪酸质量分数、不饱和脂肪酸质量分数呈显著负相关,与饱和脂肪酸质量分数、饱和脂肪酸/不饱和脂肪酸比例呈显著正相关。研究结果为进一步开发我国植物油产品提供依据。     

瓜蒌籽油与不同植物油脂肪酸的分析比较

建立了甲酯化-毛细管气相色谱法测定植物油脂肪酸,选用KOH-甲醇法甲酯化,色谱柱选用DB-wax毛细管柱。对瓜蒌籽油和11种植物油进行了脂肪酸组成分析比较及聚类分析。结果表明,在植物油中瓜蒌籽油的不饱和脂肪酸含量(93.11%)最高,且含有特有的共轭亚麻酸,瓜蒌酸(24.34%)、α-桐酸(3.82%)及梓树酸(1.23%)。植物油中脂肪酸组成均含有棕榈酸(C_(16︰0))、油酸(C_(18︰1))、亚油酸(C_(18︰2))及花生酸(C_(20︰0)),以油酸和亚油酸的含量居高。瓜蒌籽油与葵花籽油、核桃油、大豆油、芝麻油、玉米油及红花油归为一亚类,又因特有的共轭亚麻酸独为一类。     

中国大豆脂肪酸组成状况的研究

本文报导了1983—1985年3年间从中国19个省(区)收集的348份中国大豆样品的脂肪酸组成的测定结果。此结果表明,大豆中脂肪酸含量在1%以上的脂肪酸为棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸;3年测定出的饱和脂肪酸总量分别为14.9%、14.7%和14.5%,不 饱和脂肪酸总量分别为85.0%、85.1%和85.4%。饱和脂肪酸如棕榈酸和硬脂酸含量较为稳定,而不饱和脂肪酸中的油酸、亚油酸及亚麻酸含量变化幅度较大,且存在明显的相关关系,其相关系数 r 分别为;油酸与亚油酸-0.93—-0.96;油酸与亚麻酸-0.72—-0.79;亚油酸与亚麻酸0.47—0.62,显著性水平均为0.01。同时、分析结果还表明,上述三种脂肪酸的含量明显受气温的影响,油酸与大豆开花鼓荚期平均气温间的相关系数为0.34-0.40;亚油酸为-0.23—-0.30;亚麻酸为-0.56—-0.61,显著性水平<0.05。此外,本文根据中国大豆脂肪酸状况对大豆脂肪的利用进行了讨论。     

香薷籽油脂肪酸组成分析

为开发利用香薷籽资源 ,对香薷籽油物理化学性质和脂肪酸组成进行了分析测定。结果表明 ,香薷籽含油率为 4 2 .38% ,香薷籽油脂肪酸组成中α -亚麻酸的含量为 5 8.0 6 % ,亚油酸为 2 0 .70 % ,油酸为 11.70 % ,棕榈酸为 6 .93% ,硬脂酸为 2 .6 0 %。香薷籽油不饱和脂肪酸含量高达 90 .4 6 % ,是不饱和脂肪酸含量极高的植物油之一。     

火麻油总脂肪酸及sn-2位脂肪酸组成分析

采用气相色谱法测定火麻油中总脂肪酸和sn-2位脂肪酸的组成和含量,并与其他9种常见植物油进行对比,旨在为火麻油的营养价值研究提供基础数据。结果表明,3种不同品牌火麻油主要由软脂酸（C16∶ 0）、硬脂酸（C18∶ 0）、油酸（C18∶ 1n9c）、亚油酸（C18∶ 2n6c）、α-亚麻酸（C18∶ 3n3）组成,其中多不饱和脂肪酸含量为70.57%~78.73%,sn-2位多不饱和脂肪酸含量为77.61%~83.74%,说明以亚油酸和α-亚麻酸为主的多不饱和脂肪酸更易连接在甘三酯结构的sn-2位上。另外,对比其他9种常见植物油,火麻油总脂肪酸和sn-2位脂肪酸中油酸含量均最低,亚油酸和亚麻酸含量较高;多不饱和脂肪酸含量均最高,分别为77.90%和83.74%;n-6系脂肪酸与n-3系脂肪酸比例分别为3.7∶ 1和4.2∶ 1。研究结果表明,火麻油是一种不饱和脂肪酸含量较高且易于被人体吸收代谢的植物油。     

气相色谱-质谱法定性定量测定糜子中的脂肪酸

采用气相色谱-质谱法对糜子中脂肪酸进行定性、定量分析。结果共鉴定出14 种脂肪酸,相对含量为96.9%,其中不饱和脂肪酸8 种（64.533%）,主要有亚油酸（12.371%）、油酸（44.157%）、亚麻酸（1.173%）等。可见糜子中脂肪酸主要以不饱和脂肪酸为主,是优质脂肪酸。通过回归方程计算得出：糜子中棕榈酸、油酸、硬脂酸、亚油酸、亚麻酸的含量分别为100.261、165.309、23.402、52.181、17.516 mg/100 g。通过与其他杂粮进行比较,结果表明糜子和小米、高粱、小麦、燕麦、水稻一样均含有硬脂酸、油酸、亚油酸、亚麻酸和棕榈酸等,不饱和脂肪酸含量高,富含亚油酸和亚麻酸;本研究可为糜子品质的进一步开发和研究提供理论依据。     

中国大豆脂肪酸组成状况的研究

本文报道了1983—1985年三年间从中国19个省(区)收集的348份中国大豆样品的脂肪酸组成的测定结果。此结果表明,大豆中脂肪酸含量在1％以上的脂肪酸为棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸;三年测定出的饱和脂肪酸总量分别为14.9％、14.7％、14.5％,不饱和脂肪酸总量分别为85.0％、85.1％、85.4％。饱和脂肪酸如棕榈酸和硬脂酸含量较为稳定,而不饱和脂肪酸中的油酸、亚油酸及亚麻酸含量变化幅度较大,且存在明显的相关关系,其相关系数r分别为:油酸与亚油酸之间-0.93—-0.96;油酸与亚麻酸之间-0.72—-0.79;亚油酸与亚麻酸之间0.47—0.62,显著性水平均为0.01。同时,分析结果还表明,上述三种脂肪酸的含量明显受气温的影响,油酸与大豆开花鼓荚期平均气温间的相关系数为0.34—0.40;亚油酸为-0.23—-0.30;亚麻酸为-0.56—0.61,显著性水平<0.05。此外,本文根据中国大豆脂肪酸组成状况对大豆脂肪的利用进行了讨论。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.