食品中丙烯酰胺形成途径的研究进展

丙烯酰胺是一种有神经毒性和潜在致癌性的物质,2002年首次发现在高温油炸后的富含碳水化合物食品中存在,引起了世界各国研究者的广泛关注.综述了食品高温加工过程中丙烯酰胺形成的主要途径,天冬酰胺与还原糖发生Maillard(美拉德)反应.Strecker途径和N-糖苷途径是丙烯酰胺形成的主要途径;丙烯酸途径由于受自由氨的限制,虽然在食品中常见但生成丙烯酰胺的量比较少.     

食品中丙烯酰胺的控制措施研究进展

该文阐述了食品中丙烯酰胺的毒性与控制方法。在食品加工过程中可以通过控制温度、加热时间、添加相关抑制剂等方法对丙烯酰胺加以控制。食物在油炸、烘焙等高温条件下容易产生丙烯酰胺,主要产生途径是美拉德反应,因此,食用薯条、面包等油炸、焙烤食品会摄入丙烯酰胺。丙烯酰胺具有神经毒性、生殖毒性、基因毒性、致癌性等,需要选择合适的方法控制其产生。     

食品中丙烯酰胺研究进展

丙烯酰胺是一种对人体有神经毒性和潜在致癌性的物质,2002年首次发现在高温油炸后的富含碳水化合物食品中存在,并引起了世界各国研究者的广泛关注.本文就丙烯酰胺的性质、食品中丙烯酰胺的研究渊源、分析方法、含量分布、形成机制以及工艺控制等方面的研究进展进行了综述,并提出今后的深入研究方向.     

煎炸和焙烤过程中油脂对丙烯酰胺形成影响研究进展

丙烯酰胺是一种对人有神经毒性和潜在致癌性的化合物,自2002年被报道在一些高温加工的淀粉类食品中有较高含量后,引起各国学者的广泛研究。综述了煎炸和焙烤食物加工过程中油脂对丙烯酰胺形成的影响,主要包括油炸食品加工参数、油脂种类、油脂氧化和抗氧化剂对丙烯酰胺形成的影响,以及油脂热解产物对丙烯酰胺形成的影响及其可能机制。同时展望了今后的研究方向,旨在为从油脂角度控制丙烯酰胺的形成提供参考。     

丙烯酰胺毒性及油炸食品丙烯酰胺抑制方法研究进展

丙烯酰胺是富含碳水化合物和氨基酸的食品在高温加热下发生美拉德反应产生的,其对人体有一种潜在致癌作用.综述了丙烯酰胺的一些毒性,以及抑制油炸食品中丙烯酰胺产生的一些方法.     

油炸食品中丙烯酰胺的研究进展

丙烯酰胺对动物有致癌性、神经毒性、生殖发育毒性的作用,目前,丙烯酰胺已被归为对人类很可能致癌的物质,天冬酰胺酸与还原糖发生美拉德反应是生成丙烯酰胺的主要原因。为了减少丙烯酰胺在油炸食品中的含量可采取多种措施:选择最适的原料贮藏条件、前处理、加工及烹调方式、温度、时间、pH值、添加剂种类,以及已经形成的丙烯酰胺反应。在日常生活中,可通过国家健全食品安全管理、企业完善食品安全体系和公众提高食品安全认知水平来减少和控制丙烯酰胺的摄入。     

欧盟将出丙烯酰胺新规

正据报道,欧盟委员会拟制定即食食品中丙烯酰胺的限量标准,包括婴儿食品、薯片、谷物早餐等。丙烯酰胺限量水平以及涉及到的食品名单将在年底公布。丙烯酰胺是一种可增加癌症风险的化学污染物,主要在油炸、烘焙和烤制等高温加工过程中产生。1994年丙烯酰胺被国际癌症研究中心列为2A类致癌物,对人类具有潜在致癌性,长     

控制食品中丙烯酰胺含量的方法研究进展

近年来,食品的安全一直是个人和社会所关注的重要问题。但是目前发现,人们常食用的富含淀粉类的食品经过长时间高温烹调会产生一种对人体具有潜在致癌作用的物质--丙烯酰胺(AA)。AA 具有神经毒性、遗传毒性和潜在致癌性,因此控制食品中AA 含量尤为重要。本文在食品中AA 形成机理的基础上,概述了目前国内外在控制食品中AA 形成的一些方法。     

油炸食品中丙烯酰胺的生成、毒性及检测方法的研究进展

油炸食品因其独特的风味和诱人色泽,深受消费者喜爱。但高温油炸过程产生的2A级致癌物丙烯酰胺(Acrylamide,AA ),受到人们的广泛关注。油炸食品是一种深受消费者喜爱的食品,在食品产业中具有重要地位,而AA在富含淀粉的油炸食品中含量较高,在生产加工过程中伴随美拉德反应途径或丙烯醛途径生成,不同的食品原料、食品预处理方法、加工工艺条件都会对其生产有影响。由于消费者和食品工业对丙烯酰胺关注度的增加,关于丙烯酰胺检测方法的相关研究引发了广泛的讨论。除了使用常用的方法检测油炸食品中的丙烯酰胺外,近年来还出现了许多新型检测方法。本文从油炸食品中的丙烯酰胺生成途径与机制出发,总结探究其系列毒性,归纳近年来油炸食品中丙烯酰胺检测的传统与新兴方法,以期为油炸食品的生产加工提供科学依据,为控制油炸食品中的丙烯酰胺形成提供一定的理论支撑和参考。     

丙烯酰胺的形成机理、危害及预防措施

食品在加工过程中由于加工条件或加工原料不当会或多或少地产生一些对人体有害的物质。本文主要阐述了丙烯酰胺在食品加工过程中形成情况及其危害，同时提出一些避免形成的措施。     

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.     

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.     

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.     

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.     

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.     

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 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.