不同质量分数NaCl和CaCl2盐溶液解冻对金枪鱼品质的影响

采用不同质量分数NaCl和CaCl2溶液对金枪鱼鱼块进行解冻,测定并分析解冻时间、a*值、盐溶性蛋白含量、质构等指标,并对解冻后金枪鱼鱼肉的微观组织结构进行观察比较,研究不同质量分数盐溶液解冻对金枪鱼品质的影响。结果表明：对于同类盐溶液,随着盐溶液质量分数增加,金枪鱼鱼块的解冻速率和渗盐量增加。经质量分数3%?CaCl2解冻后的金枪鱼鱼肉保水性、盐溶性蛋白含量较高,质构最理想,微观组织结构最完整。综上,采用质量分数3%?CaCl2解冻,能够减轻解冻过程对金枪鱼鱼肉的影响,维持金枪鱼的新鲜度。?     

抗氧化剂对金枪鱼肉冻藏过程中组胺的抑制作用

利用C18柱、紫外检测器的高效液相色谱建立快速准确检测金枪鱼鱼肉中组胺含量的方法和技术,并对抗氧化剂对金枪鱼储藏过程中组胺产生的抑制作用进行研究。对不同部位的鱼肉采用不同抗氧化剂浸泡处理,检测不同储藏时间下组胺含量的产生和变化。结果表明：该方法的线性回归方程为Y=5.3748X＋11.42,线性范围为10～1000μg/mL,相关系数为0.9986,加标回收率为92.0%～111.3%,检出限为3.684μg/mL,用于实际样品测定操作简单、准确灵敏、适用性强、结果满意;经抗氧化剂处理的金枪鱼鱼肉中组胺含量明显低于未经处理的,其中异VC钠和柠檬酸钠混合溶液的浸泡效果最好、VC钠次之、柠檬酸钠最差。抗氧化剂既可以防止金枪鱼鱼肉氧化变黑,又可有效降低组胺的产生。     

金枪鱼解冻方法及其品质评价的研究进展

金枪鱼具有高蛋白、低脂肪的特点,被誉为现代人不可多得的营养美食,其鱼肉品质与解冻方式有着直接的关系。综合国内外对金枪鱼解冻方法的研究——包括传统的空气解冻、冷藏库解冻、温盐水解冻,以及新兴的微波解冻、低频解冻等,并归纳、对比了这几种解冻方法的优缺点。同时通过对鱼肉品质判定指标的综述,为我国金枪鱼品质判定规范的制定提供了可靠的理论依据。     

金枪鱼中生物胺的防控技术与检测技术的研究发展

金枪鱼素有"海洋黄金"之称,由于其肉质鲜美、营养丰富而越来越受到广大消费者的喜爱。目前在我国,金枪鱼大多作为生鱼片来食用,因此鱼肉的品质以及卫生安全就成为了消费者所关注的重点。生物胺是对鱼肉安全性造成重大影响的一个因素。该文主要综述国内外生物胺的防控技术研究的最新概况,介绍了目前应用较多、前景较好的防控技术,并着重总结了近年来在金枪鱼等海产品中生物胺检测技术的研究情况,结合当前的市场需求,对今后的生物胺防控技术以及生物胺检测技术的发展做出了展望。     

金枪鱼质构特性与感官评价相关性研究

目的:质构是水产品品质的重要组成部分,为了对金枪鱼的质构做全面评价,采用感官评价和仪器分析两种方法探讨它们的相关性。方法:以3种金枪鱼的3个部位的鱼肉为研究对象,采用质地剖面检验法进行感官评定,用质构仪(TPA模式)进行仪器分析。结果:9个样品的感官评价和TPA分析结果都具有显著性差异(P0.05)。对金枪鱼TPA测定数据进行因子和主成分分析,得到2个主成分,累计方差贡献率为86.68%。对感官评定和仪器分析结果进行相关性分析,结果表明TPA测定结果与感官评定结果之间存在显著的相关性(r=-0.834-0.962,P0.01)。以TPA分析指标为自变量,感官评定指标为因变量进行逐步回归分析,得到具有统计意义的感官硬度、感官黏聚性、感官咀嚼性和感官多脂性的预测模型。结论:金枪鱼品质的质构仪器分析和感官评定具有很好的相关性,为质构仪在水产品品质评价上提供了理论依据。     

金枪鱼的加工利用技术研究进展

金枪鱼是一种重要的海洋食物资源,日本、欧美是其主要的消费市场.在我国,随着人民生活水平的提高,以金枪鱼为代表的大洋性深海鱼类深受青睐,逐渐出现在广大老百姓的餐桌上.但目前我国的金枪鱼加工利用水平落后.为了促进我国金枪鱼加工利用技术的研究,本文分别就金枪鱼肉的营养价值和肉质特性、冷冻加工、超高压加工、罐头加工、鱼松加工、寡肽的提取、多不饱和脂肪酸提取、鱼油提取和鱼肉中组胺在加工贮藏过程中的变化等方面综述了金枪鱼的加工利用技术研究现状,并对金枪鱼的加工利用发展方向进行了探讨.     

两种解冻方法对金枪鱼品质影响的比较研究

金枪鱼营养物质丰富,鱼肉鲜度下降迅速。为维持金枪鱼块解冻后的品质,采用冰盐水组合冷藏室解冻方法和传统的冷藏室解冻方法对黄鳍和大眼金枪鱼块进行解冻,比较解冻过程中温度的变化和解冻速率的快慢,对解冻后鱼块质构、K值、高铁肌红蛋白含量等品质指标进行对比,结果表明:冰盐水组合解冻相比于冷藏室解冻大大缩短了解冻时间,而且解冻后各项品质指标都优于冷藏室解冻方法,能够较好地保持金枪鱼的新鲜度、色泽和质地等,说明冰盐水冷藏室解冻方法在保持金枪鱼品质中具有一定优越性。     

金枪鱼鱼肉匀浆的黏度特性研究

为优化金枪鱼鱼肉匀浆的黏度测试条件,本文研究了不同均质时间、稳定时间、鱼肉匀浆浓度、NaCl浓度、pH及测试温度对鱼肉匀浆黏度的影响。研究结果表明:当均质1 min,稳定60 min,加溶液量(mL):肉(g)为9:1,Na l为1.2 mol/L,pH为7.5,测试温度为5℃时,可获得较稳定的鱼肉匀浆黏度测定结果,为建立通过金枪鱼鱼肉匀浆黏度测量方法评价冻藏金枪鱼品质奠定基础。     

相变蓄冷工艺在金枪鱼冷链物流中的应用研究

为研究不同相变蓄冷剂对金枪鱼配送箱内鱼肉品质的影响,本试验分别选取了纯水、质量分数18.8%的Na Cl、46.3%的乙醇以及29%的Ca Cl2溶液制作冰袋,以不加冰袋作为对照,模拟夏季金枪鱼配送箱的配送情况,对箱内温度以及金枪鱼排的中心温度、感官和理化指标进行测定。结果表明,添加相变蓄冷剂能够有效维持配送过程中金枪鱼排品质,且蓄冷材料的相变温度越低,金枪鱼肉品质维持的时间越长。18.8%的Na Cl溶液冰袋能够较好保持鱼肉的品质,可在2 h内将鱼排维持在冻结状态,适合短途配送;46.3%的Ca Cl2溶液冰袋能使鱼排在运输5 h后仍保持冻结状态,中心温度仅-20.74℃,运输末期鱼肉品质接近新鲜鱼肉,红度值高达13.61,硬度及咀嚼性为3.80 N及220.50,明显高于其他试验组,是较好的金枪鱼肉的低温蓄冷材料。     

金枪鱼鱼肉茶水脱腥条件的比较研究

以绿茶为脱腥剂,通过对不同脱腥条件下金枪鱼鱼肉腥味值的比较研究,以电子鼻技术为主要参考,结合感官评价指标分析得出了不同脱腥条件对金枪鱼鱼肉的脱腥效果,确定了最佳脱腥工艺条件。当料液比1g：5mL,茶水浓度2．5％,脱腥时间3h和料液比1g：10mL,茶水浓度1．5％,脱腥时间3h时脱腥效果最好。     

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.     

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.     

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.     

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.     

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.