基于气相色谱法的奇亚籽油脂肪酸指纹图谱构建及其掺伪鉴别

目的 基于气相色谱法(gas chromatography,GC)构建奇亚籽油的脂肪酸标准指纹图谱, 并对奇亚籽油进行掺伪鉴别。方法 以奇亚籽为研究对象,采集30批次来自多个产地的奇亚籽油作为样本,对其脂肪酸进行GC分析,通过“中药色谱指纹图谱相似度评价系统”建立奇亚籽油脂肪酸标准指纹图谱,据此鉴别掺伪量分别为10 %、20 %、30 %、40 %、50 %的菜籽油、玉米胚芽油、芝麻油、花生油、葵花仁油和大豆油的掺伪模型。结果 奇亚籽油所含脂肪酸以棕榈酸、硬脂酸、油酸、亚油酸、花生酸、γ-亚麻酸、α-亚麻酸为主;通过相似度评价30批次奇亚籽油的相似度均＞99.5 %;聚类分析结果将30批次奇亚籽油按不同产地分为6大类;利用指纹图谱可以鉴别掺伪量10%及以上菜籽油、玉米胚芽油、芝麻油、葵花仁油、大豆油掺伪模型,20%及以上花生油掺伪模型。结论 通过分析奇亚籽油脂肪酸组成并建立气相色谱脂肪酸标准指纹图谱,为鉴别纯奇亚籽油提供了一定的试验数据支撑。     

奇亚籽油的研究进展

奇亚籽油含有丰富的多不饱和脂肪酸(PUFAs),其中亚麻酸含量达60%以上,被认为是ω-3多不饱和脂肪酸的良好来源,具有抗增殖和促凋亡作用、免疫刺激剂作用、体外抗氧化和抗高血压作用以及调节血脂和肝酶等功效,食用奇亚籽油对于维持正常的生理和脑功能具有重要的意义。从奇亚籽油的提取方法及脂肪酸组成、理化性质和生物活性等方面,综述了近年来国内外有关奇亚籽油的研究报道,旨在为奇亚籽油的开发利用提供参考,并对其今后的研究重点进行展望。     

奇亚籽油的健康功效

奇亚籽是一种我国批准的新食品原料,因其含有极为丰富的多不饱和脂肪酸而受到保健食品市场的关注。奇亚籽油是以奇亚籽为原料开发的油脂产品,在全球各个国家均有生产和销售。现有研究证明,奇亚籽油具有预防心脑血管疾病、改善糖尿病、抑制肥胖等保健功效,是一种值得深入开发的油脂产品。对奇亚籽的种植及营养进行概述,主要从脂肪酸角度讨论了奇亚籽油的健康功效及原理与机制,旨在为以后关于奇亚籽油的研究提供方向及指导。     

高能电子束辐照对奇亚籽发芽率及奇亚籽毛油品质的影响

奇亚籽繁殖力超强,引入我国易形成优势种群,破坏生态系统,因此考虑对奇亚籽进行灭活后引入。探究利用辐照技术使奇亚籽丧失活力,并研究辐照对奇亚籽毛油品质的影响。结果表明:辐照处理可延缓奇亚籽开始萌发的时间,并使其发芽率降低,随着辐照剂量的增大,10 k Gy处理时奇亚籽发芽率为0;10 k Gy辐照处理与不经辐照处理的奇亚籽毛油相比,酸值显著升高(P0.05)(但仍符合亚麻籽油的一级标准),过氧化值、脂肪酸组成差异不显著(P0.05);辐照处理后奇亚籽毛油的品质高,符合亚麻籽油的一级标准。     

奇亚籽油脂肪酸乙酯的制备工艺研究

以奇亚籽油为原料,采用碱催化法制备奇亚籽油脂肪酸乙酯。对比甲醇钠、乙醇钠和氢氧化钠的催化效果,并通过单因素实验和正交实验优化奇亚籽油脂肪酸乙酯制备的工艺参数。结果表明：采用氢氧化钠为催化剂,乙酯含量和得率均最高;当酯交换温度为80 ℃、酯交换时间为1.5 h、醇油摩尔比为9∶ 1、氢氧化钠用量为油质量的0.6%时,奇亚籽油脂肪酸乙酯含量可达到89.01%。     

奇亚籽油的品质评价及其在魔芋糕中对小鼠血糖调节作用的影响

该文通过分析螺旋压榨奇亚籽油的理化性质、脂肪酸组成评价其品质,将奇亚籽油加入到魔芋糕中利用小鼠饲喂实验评价其降血糖效果。结果表明,奇亚籽油折光系数1.480 6,碘值194 g/100 g,皂化值190.1 mg KOH/g,不溶性杂质<0.01%,酸值0.55 mg KOH/g,过氧化值6 mmol/kg;奇亚籽油脂肪酸组成中α-亚麻酸和亚油酸分别占59. 35%、19. 59%且PUFA/SFA=7. 07。通过比较2组不同饲喂条件下(奇亚籽油魔芋糕组、不含奇亚籽油魔芋糕组)小鼠的体重、空腹血糖的指标,得出2组产品对小鼠体重调节作用无显著性差异(P>0.05),对小鼠空腹血糖调节作用存在显著性差异(P <0.05),饲喂后2组小鼠空腹血糖值分别为5. 98、6. 84 mmol/L(模型组为7. 99 mmol/L)。表明奇亚籽油魔芋糕对小鼠血糖调节作用更好,可为制备奇亚籽油及魔芋粉新型产品提供理论依据。     

微波预处理对奇亚籽出油率及油脂品质的影响

采用微波技术对奇亚籽进行预处理后低温压榨制油,测定奇亚籽油理化指标、营养及抗氧化指标,探讨微波预处理条件对奇亚籽出油率以及奇亚籽油品质的影响。结果表明：原料的水分含量、微波时间、微波功率对奇亚籽出油率和奇亚籽油的理化指标、黄酮含量、多酚含量及DPPH·和O-2·清除能力均有一定的影响,对奇亚籽油脂肪酸相对含量影响较小。经单因素实验和正交实验得出：微波预处理奇亚籽的适宜工艺条件为奇亚籽水分含量12%、微波时间3 min、微波功率600 W,在该条件下奇亚籽出油率可达到21.05%,奇亚籽油酸价（KOH）0.52 mg/g、过氧化值0.44 mmol/kg、黄酮含量318.25 mg/kg、多酚含量28.00 mg/kg,DPPH·和O-2·清除率分别为2479%和26.84%。     

超临界CO_2萃取奇亚籽油工艺优化及抗氧化活性的研究

为高效地提取奇亚籽油,采用单因素及正交实验优化超临界CO_2萃取奇亚籽油最佳工艺条件,考察物料粒度、萃取压力、萃取温度以及萃取时间4个因素对奇亚籽油萃取率的影响,并对奇亚籽油进行抗氧化活性的测定。结果表明:超临界CO_2萃取奇亚籽油最佳工艺条件为物料粒度60目、萃取压力25 MPa、萃取温度50℃、萃取时间2.5 h,奇亚籽油萃取率为85.50%。奇亚籽油中富含不饱和脂肪酸,占总脂肪酸的88.22%,其中亚麻酸高达69.86%。抗氧化实验表明,奇亚籽油对DPPH自由基和ABTS~+自由基具有较强的清除作用,对超氧阴离子自由基也显示出一定清除效果。     

烘烤条件对奇亚籽油理化性质及脂肪酸组成的影响

对奇亚籽进行烘烤、压榨取油,测定不同烘烤条件(温度、时间)下奇亚籽油的理化性质及脂肪酸组成,探讨烘烤温度和时间的影响。结果表明:随着烘烤温度的升高和烘烤时间的延长,奇亚籽油色泽加深,酸价、过氧化值、K_(232)、K_(268)均呈现上升趋势,且180℃烘烤50 min以上较其他条件下显著升高(p0.05);烘烤条件对脂肪酸组成无影响。故烘烤奇亚籽不宜在高温下进行,若采用180℃烘烤时,则时间不应超过50 min。     

奇亚籽油的提取工艺、生物活性及开发前景的研究进展

奇亚籽油含有丰富的不饱和脂肪酸,其中含有60%以上的α-亚麻酸,是一种良好的不饱和脂肪酸,具有抗氧化、降血脂、抗肿瘤与促凋亡、免疫刺激以及增强骨骼等生物活性。此外,奇亚籽油中有甾醇、生育酚、角鲨烯、多酚等多种有效成分,被认为是一种天然抗氧化剂。本文从奇亚籽油的提取工艺、生物活性等方面总结近年来国内外关于奇亚籽油的研究进展,展望奇亚籽油未来的开发前景,为其油料的进一步开发和应用提供依据。     

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.     

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.     

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