玉米中的过敏原及物理加工对食品致敏性的影响研究进展

随着食用玉米的人群越来越广泛,玉米过敏问题日渐凸显。对玉米过敏的有效防御被人们所重视,加工通过改变过敏原的蛋白结构可以使过敏原致敏性降低。其中食品加工对过敏原致敏性的研究主要集中在热处理方面;然而各种非热方法,如微波、超高压等食品加工新技术,在降低食品的致敏性方面也有广阔的应用前景。相比来说非热方法通常是有利的,它们能够保留在热处理过程中经常改变的感官特性,如营养成分和风味。本文综述了玉米过敏原研究现状,总结了玉米中的过敏原,描述了对食物进行热处理和非热处理在改变食物过敏原反应性方面的作用,并且提出多种加工方式联合使用来降低玉米过敏原致敏性的未来研究方向,为玉米过敏的防御提供参考。     

柑橘属果实中过敏原几丁质酶的表达和B细胞抗原表位的预测

I类植物的几丁质酶(chitinase)是许多植物性食品中一种非常重要的过敏原,与乳胶-水果综合症有着密切的关系。大部分致敏性植物中的几丁质酶对人体的健康有着潜在的危害。本文以柑橘属中的过敏原几丁质酶为研究对象,通过比较柑橘属中不同来源的果实,如琯溪蜜柚、甜橙和温州蜜柑中的几丁质酶基因表达含量,得到温州蜜柑果实的表达量最高。通过Genebank搜索得到几丁质酶的氨基酸序列,采用同源比对说明在不同的物种中可能会导致交叉过敏的现象。最后利用DNAStar软件预测得到几丁质酶的二级结构,当氨基酸的二级结构是β-转角和无规则卷曲,同时抗原指数0、柔韧性0、表面可及性1和亲水性0的氨基酸区域时,形成B细胞抗原表位的可能性较大。综合这些参数结果表明几丁质酶的B细胞抗原表位结合氨基酸序列的可能区域是在62~69、96~100、126~133、145~149、155~159、169~172、179~182、189~190、256~262,通过预测氨基酸的区域,为制备相应的抗体、培育低过敏品种等后续研究提供一定的理论依据。     

植物几丁质酶纯化、测定及应用研究进展

植物几丁质酶是植物体中能够水解几丁质多聚体的一种致病性相关蛋白(Pathogenesis-relatedproteins)。近年来对于几丁质酶的研究报道中,大量新型的植物几丁质酶被分离纯化,并建立了不同的酶活测定方法,在几丁质酶的结构及分类方面也逐步有了系统的研究。从几丁质酶的结构及分类,分离纯化以及已建立的酶活测定方法等方面取得的新进展进行了综述,并展望了几丁质酶在农业、食品生产及药用领域的应用前景。     

水果过敏原及其致敏性消减技术研究进展

水果含有丰富的维生素、多酚等抗氧化物质,可延缓衰老,促进人体健康,然而水果过敏造成的食品安全问题日益突出。概述了常见的水果过敏原与交叉过敏反应,水果致敏性消减技术的原理与研究进展。常见的7大类水果过敏原主要包括类甜蛋白、Bet v 1同源蛋白、脂质转移蛋白、抑制蛋白、几丁质酶、半胱氨酸蛋白酶和β-1,3-葡聚糖酶。交叉过敏反应是引发水果过敏的主要原因之一,当多种过敏原含有相似的结构序列或决定簇时可引发明显的交叉过敏反应。其中,花粉中的Bet v 1最容易与常见的水果引起交叉过敏反应。高温、高压、脉冲电场、超声波、辐照等物理加工技术可通过二硫键的断裂与重排、氢键的增强或削弱、肽链的断裂或交联等作用直接破坏水果过敏蛋白质的结构;碱液或酶处理等化学消减技术可通过破坏过敏原的蛋白结构,降解过敏原致敏性表位。目前水果致敏性消减技术的研究较少,其效果也不够理想。未来可通过分子动力学模拟、新型食品加工方法等多技术联合,精准靶向控制水果致敏性;生物育种和基因编辑等新技术培育脱敏水果新品种,从根本上解决水果致敏性难题,为低敏或脱敏水果产品的开发与产业化应用提供科学依据。     

花生致敏性评估方法及食品加工对其致敏性影响的研究进展

花生是“8大类”过敏原食物之一，因其诱发严重的临床症状及日益上升的发病率而受到广泛关注。文章概述了花生过敏原(Ara h 1-18)的结构特性、免疫特性及体内和体外评估方法，总结了不同食品加工对花生致敏性的研究进展，并展望了未来食品加工技术对消减花生致敏性的研究方向。     

酶解法在鸡蛋脱敏中的应用研究进展

鸡蛋是联合国粮农组织(FAO)认定的八大类主要过敏食品之一,选用合适的加工方法可以降低鸡蛋的致敏性,其中酶解法是最有效的方法。本文论述鸡蛋中的4种主要过敏原,并详细阐述酶解对鸡蛋中主要过敏原结构和致敏性的影响,以期为开发低致敏性或无致敏性蛋制品提供一定的科学依据。     

低致敏食品制备技术及其工业化应用研究进展

食物过敏是联合国粮农组织和世界卫生组织认定的全球性食品安全问题之一。在食品加工多元化的背景下,食物过敏患者要完全避免过敏原十分困难,研发低致敏食品对食物过敏患者的安全膳食至关重要。总结了低致敏食品制备技术的加工技术原理;以蒸煮、微波和烘烤为主的热加工技术通过加热诱导蛋白质变性的方式破坏致敏性构象性表位;高压、脉冲电场、脉冲光、低温等离子体、辐照和超声等非热加工技术可以通过过敏原蛋白结构修饰、多肽链断裂、新化学键的产生等方式直接破坏致敏性表位;酶水解、酶交联、糖基化、微生物发酵等其他加工方法则通过改变蛋白质构象或将蛋白质与糖类物质结合,破坏或隐藏过敏原致敏性表位。另外,对工业化低致敏蛋白配料的加工方法和生产现状进行了阐述分析。基于酶法水解的部分水解乳蛋白和深度水解乳蛋白已经可以工业化生产,其他消减食物致敏性的方法以及其他低致敏蛋白配料值得进一步研究。希望可以为工业化生产低致敏食品提供参考。     

发酵法对降低食品过敏原的作用

食物过敏已经成为了一个同时挑战消费者和食品加工厂的公共卫生问题。随着生物技术与工程食品的快速发展,如何脱除食物中的过敏原,制造低致敏性食品已经成为食品科技工作者的研究课题。发酵法能够降低食品中的过敏原,但是,目前发酵法在食物脱敏上的应用还不够广泛。通过查阅文献资料,总结了前人的一些实验成果,从大豆、牛乳等几个方面予以阐述。通过选用合适的菌株对这些食品进行发酵,可以降低其致敏性,但是并不能完全脱除致敏性。选择合适的菌株种类,调整其配比,在最适菌株生长的条件下进行发酵才能够将食品的致敏性降至最低。     

食品中过敏原及其检测方法的研究进展

近年来食物过敏作为食品安全的热点问题在全球引起了广泛关注。目前食物过敏仍无有效的根治方法,严格避免摄入致敏食品仍是过敏性疾病防治的最有效方式。因此,食品中过敏原的识别鉴定、性质分析及检测方法的研究至关重要。本文针对八大类过敏食物,从分子结构、免疫学特性等方面介绍了常见食物过敏原的研究进展;归纳了现阶段用于食品中过敏原分析的常规检测方法,以及在此基础上发展而来的新兴检测丰富,并比较分析了不同检测技术方法的优缺点。相比于植物源性过敏原,动物源性过敏原的相关研究有待深入,尤其是蛋白家族的确定及空间结构解析等是未来动物源性过敏原研究的重要方向;目前食品中常见过敏原的常规检测方法及新兴检测方法依然存在检测效率和准确性不高、成本昂贵等局限性,建立高效、准确、低成本的过敏原检测方法仍是该研究领域发展的重要趋势。     

芝麻过敏原及其致敏性消减技术研究进展

芝麻是新的“8大类”过敏食物之一,芝麻过敏反应由于其潜在危害性及其日益上升的发病率而越来越引起全世界的普遍重视,因此研究芝麻致敏性消减技术在保障食品安全方面具有重要意义。概述了芝麻主要过敏原(Ses i 1～Ses i 7)的结构和免疫特性,及其致敏性消减技术原理和研究进展;已报道的芝麻过敏原有7种,属于2S白蛋白、7S类豌豆球蛋白、油质蛋白和11S球蛋白,其中11S球蛋白和2S白蛋白是主要的过敏原蛋白。利用热加工技术消减芝麻致敏性,主要通过煮沸、微波、烘焙等工艺引起过敏原的解聚、变性进而破坏致敏表位;高压、辐照、发酵、酶解等非热加工技术通过氢键、疏水键等化学键的变化、多肽链的断裂引起蛋白结构变化,从而掩盖或直接降解致敏表位。另外,结合其他食品过敏原,对芝麻过敏原的潜在消减技术,包括脉冲电场、冷等离子体、超声波、脉冲光、糖基化改性和复合加工技术等进行了阐述分析。未来需要进一步研究芝麻不同过敏原的致敏表位、不同加工工艺对过敏原结构及致敏性影响、开展血清学、细胞和动物模型等致敏性评价等,以明确芝麻致敏性消减的主要机制,以期为生产低敏或脱敏芝麻产品奠定理论依据与科学指导。     

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