普鲁兰多糖在草鱼鱼肉保鲜中的应用

探讨普鲁兰多糖溶液对草鱼鱼肉的保鲜效果。以pH值、感官质量评价、细菌总数、挥发性盐基氮和过氧化值等为鲜度指标,鱼块经不同浓度的普鲁兰多糖溶液处理5min后,于模拟常温(25℃)贮藏,测定不同时间点其鲜度的变化。结果表明：普鲁兰多糖溶液对鱼肉有明显的保鲜效果,经0.50%多糖溶液处理的鱼肉,在模拟常温条件下贮藏12h后细菌总数和TVB-N值分别为2.15×105CFU/g和19.74mg/l00g,均低于淡水产品二级鲜度的要求,保鲜效果最好。     

嗜酸乳杆菌NX2-6细菌素在猪肉保鲜上的应用

为探讨嗜酸乳杆菌NX2-6细菌素对冷鲜猪肉的保鲜效果,选取新鲜猪肉为研究对象,以菌落总数、pH、挥发性盐基氮、感官评价为鲜度指标,经不同浓度嗜酸乳杆菌NX2-6抑菌溶液浸泡30 min后,于4 ℃条件下贮藏9 d,测定不同时间点其鲜度的变化。结果表明,从3 d开始,4% S组的菌落总数水平就始终在对照组的1/10以下;pH变化拐点比对照组延迟2 d出现;TVB-N值比对照组推迟2 d到达国标最高检出限;从3 d开始中高剂量处理组气味评分始终显著优于对照组(p<0.05)。结论:4%嗜酸乳杆菌NX2-6抑菌溶液的保鲜效果最佳,猪肉变质较对照组可延缓2 d。     

唾液乳杆菌O2A及其所产抑菌物质应用于水产品防腐的研究

以鳙鱼为研究对象,将鱼肉浸泡于唾液乳杆菌O2A菌液或发酵上清液中,通过感官评定,测定菌落总数、pH值、挥发性盐基氮总量,探究唾液乳杆菌O2A保鲜液及其复合保鲜液对鱼肉的保鲜作用。结果表明:唾液乳杆菌O2A菌液浸泡处理后的鱼类保鲜效果显著,唾液乳杆菌O2A菌液处理鱼肉菌落总数最少,pH值上升最缓慢,产生挥发性盐基氮最少;唾液乳杆菌O2A菌液联合海氏肠球菌A菌液处理鱼肉保鲜效果要好于单用唾液乳杆菌O2A菌液。唾液乳杆菌O2A菌液具有良好的保鲜效果,具有应用在水产品保鲜的广阔前景。     

Nisin生物保鲜剂对冷藏草鱼片的保鲜效果研究

主要研究了以0.5%的乳酸链球菌素(Nisin)作为保鲜剂对冷藏草鱼片的保鲜效果,通过测定微生物总数、色差值、挥发性盐基氮(TVB-N)值、挥发性气味、pH值和K值等新鲜度指标来评价草鱼片品质的变化。结果表明:在贮藏过程中,经0.5%的Nisin保鲜剂处理过的草鱼片菌落总数、TVB-N值和K值均小于对照组;pH值先降低后升高;Nisin对冷藏草鱼的颜色没有明显影响;电子鼻检测结果表明,Nisin可有效减缓鱼肉风味劣变。由此可见,0.5%的Nisin保鲜剂对冷藏下的草鱼片有较好的保鲜效果,可以适当延长草鱼片的货架期3 d。     

基于植物乳杆菌处理的南湾鳙鱼肉在贮藏期内的品质变化

该研究通过利用不同浓度的植物乳杆菌菌悬液处理南湾鳙鱼肉,将其放置在PE保鲜袋中,分别贮藏在4 ℃和常温条件下,每间隔2 d对其TVB-N值、硫代巴比妥酸（TBA）、pH及感官四个指标进行测定,分析鱼肉在贮藏期间各指标的变化规律。结果显示,不同浓度菌悬液处理的南湾鳙鱼肉（与对照组相比）,在贮藏期间TVB-N、TBA、pH上升速率均有所减缓,肉质感官评价较对照组表现更优秀;当贮藏4 ℃下植物乳杆菌菌悬液质量浓度为0.8%时,贮藏期间南湾鳙鱼肉的品质最好,贮藏期7 d后鱼肉的挥发性盐基氮（TVB-N）为29.40 mg/100 g,TBA为0.17 mg/kg,pH值为6.54,鱼肉变质时间较对照组整体可延缓2 d,这表明植物乳杆菌对鱼肉具有一定的贮藏保鲜效果,可以作为一种绿色生物保鲜剂应用于南湾鳙鱼肉贮藏保鲜。     

ε-聚赖氨酸与魔芋葡甘聚糖复配保鲜剂对草鱼片的保鲜效果

通过测定草鱼片贮藏期间感官评分、pH值、硫代巴比妥酸反应物值、总挥发性盐基氮含量、菌落总数等指标的变化,研究ε-聚赖氨酸和魔芋葡甘聚糖复配液对草鱼片在(4±1)?℃条件下冷藏12?d期间物理化学特性和保鲜效果的影响.结果表明:对照组草鱼片贮藏9?d时菌落总数达6.25?(lg(CFU/g)),感官评分较低;贮藏12?d...     

聚乙烯醇活性薄膜对大黄鱼保鲜效果及品质动态监控

为研究智能聚乙烯醇活性薄膜对大黄鱼贮藏品质的影响和由于大黄鱼鱼肉p H改变而引起的薄膜动态色差变化,先以溶液流延法制备含有1%纳米二氧化钛和3%花青素的聚乙烯醇活性薄膜,使用其包装大黄鱼贮藏于4℃,再以感官品质、脂质过氧化值、菌落总数、挥发性盐基氮和pH并结合贮藏过程中薄膜色差变化,作为评定大黄鱼在包装贮藏过程中的鲜度指标。结果表明:在4℃贮藏期间,聚乙烯醇/纳米二氧化钛/花青素薄膜包装处理组的感官品质、脂质过氧化值、菌落总数、挥发性盐基氮和pH均优于空白和使用纯聚乙烯醇薄膜包装处理组,且在贮藏第16 d的菌落总数达到7.11lg cfu/g,其他实验组在贮藏第12 d达到7.14lg和7.03lg cfu/g,其货架期延长了4 d。在20 d贮藏期间过程中,聚乙烯醇/纳米二氧化钛/花青素薄膜表现出灰棕色(0 d)、红棕色(4 d)、淡红棕色(8 d)、肉色(12 d)、灰色(16 d)和深灰色(20 d),通过可见的颜色变化依次响应贮藏过程中大黄鱼鱼肉pH的改变。因此,本研究所制备的智能聚乙烯醇活性薄膜不仅有益于食品的贮藏保鲜,还能够作为颜色指示器在食品贮藏过程中起到动态监控的作用。     

不同切割干姜对真空包装草鱼片新鲜度的影响

研究不同切割处理的干姜对真空包装草鱼片(草鲤鱼)新鲜度的影响具有重要意义。以挥发性盐基氮(TVB-N),pH值,菌落总数(TBC),水分含量和电子鼻风味等作为草鱼新鲜度评价指标,对50 g鱼肉(对照组),50 g鱼肉+2 g干姜丝,50 g鱼肉+2 g干姜丁等VC1、VC2和VC3三组实验进行探究。结果表明:3组样品的pH值明显不同,而挥发性盐基总氮、菌落总数和水分含量等指标无显著性差异。     

不同贮藏温度下鲫鱼鱼片品质变化研究

为探究不同贮藏温度下鲫鱼鱼片保鲜效果,试验设置0℃(冰藏)、4℃(冷藏)、-3℃(微冻)和-18℃(冻藏)4组试验,以质构分析、硫代巴比妥酸(TBA)、高铁肌红蛋白、挥发性盐基氮(TVB-N)、微生物等指标变化为依据测定不同贮藏温度条件下鲫鱼鱼片的品质变化。结果表明,随着贮藏时间的延长,不同贮藏温度条件下鲫鱼鱼片的质构特性、高铁肌红蛋白、挥发性盐基氮(TVB-N)、菌落总数均出现不同程度的上升,温度越高,上升速度越快。其中,4℃(冷藏)下的鲫鱼鱼肉的贮藏货架期为9 d,0℃(冰藏)下的鲫鱼鱼肉的货架期为15 d,-3℃(微冻)和-18℃(冻藏)下鲫鱼鱼肉的货架期较长。综合各项理化指标可知鲫鱼鱼片在微冻和冰温、冻藏条件下保鲜效果明显优于冷藏。     

竹叶抗氧化物在冷却羊肉中的保鲜效果

主要探索竹叶抗氧化物(antioxidant of bamboo,AOB)在冷却羊肉保鲜中的应用效果。羊肉经竹叶抗氧化物溶液浸泡后内附吸水垫真空包装并于4℃贮藏,每5d对其进行感官评定、细菌总数、pH值以及挥发性盐基氮值的测定。结果表明,用质量浓度为0.15g/100mL的竹叶抗氧化物溶液浸泡羊肉后,在贮藏过程中其感官、细菌总数、pH值以及挥发性盐基氮指标均为最好,保鲜时间比对照组样品延长5～7d。     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.