n-3多不饱和脂肪酸对疾病的预防与治疗作用

n-3多不饱和脂肪酸主要源于亚麻籽、胡桃仁、大豆以及海洋生物。增加n-3多不饱和脂肪酸摄取量可以促进视网膜、大脑和神经系统发育。n-3多不饱和脂肪酸通过各种途径降低人体心血管疾病和炎症的发生,降低糖尿病患者血清低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平。膳食中增加n-3多不饱和脂肪酸的含量可以对心血管疾病、糖尿病、炎症等患者有辅助治疗效果;n-3多不饱和脂肪酸可以作用于神经细胞,对注意力不集中、抑郁症、精神分裂症有一定的疗效。n-3多不饱和脂肪酸可抑制体外培养的乳腺、前列腺和结肠癌细胞增生,促进细胞凋亡。     

n-3/n-6多不饱和脂肪酸的生理功能与膳食平衡研究

多不饱和脂肪酸(PUFAs)是一种独特的生物活性物质,对人体有着重要的生理功能。其中,n-3/n-6多不饱和脂肪酸具有重要的生物学功能,它们在人体内的平衡对于维持细胞的正常生理功能、促进血清胆固醇的代谢、降低血液黏稠度以及增强记忆、活跃思维等方面起着重要作用。综述n-3/n-6多不饱和脂肪酸的生理功能及膳食平衡等研究进展,为后续研究提供理论依据。     

n-3多不饱和脂肪酸对中老年人群精神及视力影响的研究进展

通过综述n-3多不饱和脂肪酸对中老年人群疾病,特别是对中老年人群认知下降、老年痴呆、抑郁、黄斑变性等作用的研究,阐述了n-3多不饱和脂肪酸对认知下降风险的降低,以及对AMD病症发生的减缓作用。同时,n-3多不饱和脂肪酸在细胞中的含量与抑郁症发病率呈负相关性。尽管确切机理有待深入研究,但绝大部分临床研究表明,补充n-3多不饱和脂肪酸可以预防中老年人群精神及视力疾病的发生。     

n-3多不饱和脂肪酸抑制骨骼肌蛋白异常分解的研究进展

胰岛素/Akt信号通路受阻所致的骨骼肌细胞蛋白异常分解,可能是骨骼肌萎缩发生的重要原因。不同n-3多不饱和脂肪酸在骨骼肌细胞内、外作用于胰岛素/Akt信号通路上的多个位点,均有助于维持通路的正常运作。其中,植物来源n-3多不饱和脂肪酸ALA能通过活化胰岛β细胞胞膜的GPR40直接促进胰岛素分泌;海鱼来源n-3多不饱和脂肪酸EPA与DHA能有效维持骨骼肌细胞内Akt活性并增加胰岛素敏感性。本文通过对相关文献的归纳总结,阐释n-3多不饱和脂肪酸基于胰岛素/Akt信号通路抑制骨骼肌细胞蛋白异常分解的机制,为通过膳食手段干预骨骼肌萎缩提供新的思路。     

膳食中n-3多不饱和脂肪酸对2型糖尿病患者血糖和胰岛素敏感性的影响

2型糖尿病是世界上最常见的慢性疾病之一。膳食中的n-3多不饱和脂肪酸可能会减少亚洲人的2型糖尿病风险, 中国2型糖尿病患者血浆磷脂n-3不饱和脂肪酸与胰岛素敏感性呈正相关。而欧美的前瞻性研究均发现, 鱼类的摄入和n-3多不饱和脂肪酸的摄入会增加2型糖尿病的发病风险, 在西方白种人群中进行的n-3多不饱和脂肪酸干预的随机对照试验也并未发现n-3多不饱和脂肪酸能够改善患者胰岛素抵抗水平或血糖水平, n-3多不饱和脂肪酸甚至可轻微地降低患者胰岛素的敏感性。本文综述了目前n-3多不饱和脂肪酸摄入量与2型糖尿病风险之间的关系。     

功能性n-3多不饱和脂肪酸的研究进展

脂肪酸是生命代谢活动中一种重要化合物，根据脂肪酸碳链数上的双键数将脂肪酸分为饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸三类。文章对n-3多不饱和脂肪酸来源、合成过程、n-3和n-6多不饱和脂肪酸的结构差异以及生物活性进行综述，为n-3多不饱和脂肪酸在功能保健食品、医学药用领域及基础研究进一步探索与全面开发提供理论依据。     

n-6/n-3多不饱和脂肪酸比例对HepG2细胞脂代谢的影响

本文研究了不同比例n-6/n-3多不饱和脂肪酸对HepG2细胞影响,通过体外培养细胞60μM不同比例LA/ALA培养24 h,通过反转录PCR研究不同比例LA/ALA对HepG2细胞SREBP-1、FAS、HMG-CR、LDLr和Apo B蛋白等脂代谢相关基因及蛋白表达量的影响。结果表明在组1(LA)、组2(10:1 LA/ALA)、组3(5:1 LA/ALA)、组4(1:1 LA/ALA)、组5(1:5 LA/ALA)、组6(1:10LA/ALA)和组7(ALA)7组比例中,1:1 LA/ALA比例处理细胞效果最佳,此比例脂肪酸通过下调HepG2细胞SREBP-1和FAS基因的表达来降低细胞TG的含量;下调HMG-CR基因的表达,上调LDLr基因的表达来降低细胞TC和LDL-C含量;通过上调SR-B1基因表达增加胆固醇逆转运,从而实现对HepG2脂代谢的有效调控。此多不饱和脂肪酸体外营养评价模型,为n-6/n-3多不饱和脂肪酸最佳营养比例推荐及食用植物油中多不饱和脂肪酸比例营养评估提供理论依据。     

高n-3多不饱和脂肪酸鸡蛋的开发研究进展

介绍了n-3多不饱和脂肪酸类别、营养功能及使用哪些饲料原料可以生产高n-3多不饱和脂肪酸鸡蛋,分析了鸡蛋中多不饱和脂肪酸的沉积规律和影响因素,并概述了高n-3多不饱和脂肪酸鸡蛋特点,以及存在的问题和解决途径,为开发高n-3多不饱和脂肪酸鸡蛋提供依据。     

膳食中多不饱和脂肪酸营养与生理功能的研究进展

概述了多不饱和脂肪酸的种类、来源、营养和生理功能的相关研究，包括n-6系列多不饱和脂肪酸、n-3系列多不饱和脂肪酸。阐述了膳食合理比例的n-6/n-3多不饱和脂肪酸是保持身体健康的关键。     

n-3多不饱和脂肪酸对结肠癌细胞HCT116抗增殖作用

目的:研究n-3多不饱和脂肪酸在结肠癌细胞内的代谢与转化,深入探究脂肪酸代谢调节因子LTB₄、PGE₂、LXA₄对结肠癌细胞HCT116的毒性作用。方法:选用结肠癌细胞HCT116为研究对象,采用不同浓度n-3多不饱和脂肪酸(ALA、EPA、DHA)和阳性药物5-氟尿嘧啶(以下简称5-FU)处理细胞,检测细胞存活率、细胞凋亡、细胞脂滴聚积、细胞脂肪酸组成变化,研究代谢因子LTB₄、PGE₂、LXA₄表达水平及其对细胞增殖影响。结果:ALA、EPA、DHA和5-FU对HCT116细胞的生长具有显著的抑制作用和诱导凋亡作用(p<0.05),ALA(200 μmol/L)、EPA(160 μmol/L)、DHA(120 μmol/L)诱导凋亡率分别为7.9%、21.8%、29.2%。ALA、EPA、DHA促进HCT116细胞内脂滴积聚状态,提高不饱和脂肪酸比例,降低LTB₄积累,提高LXA₄/PGE₂比率,使癌细胞趋向于抗炎状态。结论:n-3多不饱和脂肪酸(ALA、EPA、DHA)可通过促进抗炎因子LXA₄分泌,抑制促炎因子LTB₄生成,进而对HCT116细胞产生杀伤作用。     

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.     

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%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press