食品添加剂行业今年将探究食品添加剂"超标"问题

今年适当时候,中国食品添加剂生产应用工业协会将组织召开一次食品添加剂全行业参加的“科技大会”。主要针对食品防腐剂过量使用的问题。该科技大会将重点探究食品添加剂特别是防腐剂、抗氧剂“超标”使用的问题。     

食品添加剂6-苄基腺嘌呤等检测国标通过评审

不久前,江门检验检疫局承担制定的“进出口食品添加剂6-苄基腺嘌呤的检测方法”和“进出口食品添加剂蔗糖聚丙烯醚的检测方法”两项国家标准顺利通过了国家认监委、国家标准委和中国检科院等部门的专家评审。由于此前国内外均无相关标准,江门检验检疫局这两项国家标准顺利通过评审为今后我国对进出口食品添加剂6-苄基腺嘌呤、蔗糖聚丙烯醚的检测提供了保证。(仪器信息网)食品添加剂6-苄基腺嘌呤等检测国标通过评审     

发达国家食品添加剂研究状况

介绍了国际食品法典委员会、美国、欧盟、日本有关食品添加剂的定义和范围,食品添加剂法规标准框架结构与内容,以及各国食品添加剂的管理部门和不同的管理方式。为加强我国食品添加剂管理和进口食品中添加剂的使用管理,以及出口食品生产企业组织生产提供参考。     

食品中化学添加剂的功能与风险控制*

食品中的化学添加剂是指由化学方法合成的一类食品添加剂。本文探讨了食品中化学添加剂产生和发展的原因,指出化学合成的食品添加剂是天然物质群的一种补充与完善,概述了化学合成食品添加剂的一般性质和功能,介绍了食品添加剂联合专家委员会(JECFA)、美国、欧盟和中国对食品添加剂进入市场前的安全性评价程序和方法,以及美国、欧盟和中国在化学添加剂投入使用后实施监督管理的机构、法律依据、质量标准等,总结了影响食品中化学添加剂安全风险控制的主要因素,最后在此基础上,提出如何从政府、企业、科研三方面完善风险控制体系和有效保障食品安全的建议。     

食品新规实施 食品添加剂统统浮出水面

2010年6月1日,《食品添加剂生产监督管理规定》正式实施。根据新规,所有食品添加剂成分,必须在外包装上明示消费者。如此规定,让一直隐身于“防腐剂”、“增稠剂”等笼统说法背后的各种添加剂浮出水面。不过新包装上动辄五六种、甚至是10种以上的添加剂吓坏了不少市民。对此,国家质检总局法规司副司长许新建表示,如果生产企业严格按照食品安全标准中规定的食品添加剂品种、使用范围和用量进行添加,消费者可放心食用。     

食品添加剂与食品安全

食品添加剂是食品工业的重要组成部分,对食品的生产和质量改善起至关重要的作用。随着食品工业的发展以及人们生活水平的提高,食品添加剂的研究和安全性评价越来越受到关注。本文较系统地介绍了食品添加剂的作用、分类,以及食品添加剂的安全性问题,综述了食品添加剂的发展趋势。     

非食用色素金黄粉简介

简单综述了金黄粉的物理化学性质、毒性以及食品中金黄粉的检测方法。     

“食品添加剂”教学分析

选择《化学与生活》模块中的“食品添加剂”作为选修课题,让学生认识化学与生活的重要关系,激发学生学习化学的兴趣,促进科学素养的全面提高。在教学实践中实施探究学习的教学方法,获得了很好的教学效果。     

75项食品安全国家标准6月1日起实施

<正>国家卫生计生委发布了75项新食品安全国家标准。这些标准将于今年6月1日起正式实施,这对于提升出口食品生产企业的管理水平,提高我国出口食品安全水平具有积极意义。本次公布的GB 29924–2013《食品添加剂标识通则》对食品添加剂的标签、说明书和包装等内容进行了规范。通过参考相关国际标准,并结合我国食品添加剂的实际生产、经营和使用情况,新标准规范了食品添加剂标签标识的术语、定义、基本内容和有关要求,进一步细化了对食品添加剂标     

9部门要求加强食品添加剂监管工作

不久前,卫生部、食品药品监管局、工商总局、质检总局等9部门联合发布《关于加强食品添加剂监督管理工作的通知》,《通知》明确指出,食品生产者和餐饮单位所使用的额外添加剂,必须取得生产许可证或者有效期限内的卫生许可证,食品销售者不得在销售过程中添加任何非食用物质和食品添加剂。2008年12月,9部门在全国开展打击违法添加非食用物质和滥用食品添加剂专项整治行动以来,监管工作所面临的形势依然严峻,主要有3大问题:(1)有的食品生产经营单位未按照相关法规和标准的规定采购、查验和使用食品添加剂;(2)食品添加剂生产经营不规范的问题依然存在,复合食品添加剂问题突出;(3)食品添加剂标签、说明书不规范,夸大宣传使用效果和擅自扩大使用范围,误导食品生产经营者使用。为此《通知》要求,下阶段工作将继续加强对食品添加剂生产经营和使用的监管,包括严格食品添加剂生产许可和监督管理工作,严把生产许可关;规范复合食品添加剂的生产,把复合食品添加剂纳入工业产品生产许可范围,严禁使用非食用物质生产复合食品添加剂;严格规范食品添加剂经营主体准入行为,加强对经营活动的监督管理,督促销售者建立进货查验制度等自律机制;规范食品添加剂标签、说明书,包装上必...     

"Alpha"-, "beta"- and "delta"-anhydrodigitoxigenin

The syntheses of 3β-hydroxy-5β-carda-14, 20:22-dienolide (= «β»-anhydro-), 3β-hydroxy-5β-carda-8:14, 20:22-dienolide (= «α»-anhydro-) and «δ»-anhydro-digitoxigenin (= probably 3β-hydroxy-5β, 14β-carda-8, 20:22-dienolide) by the best ways known to date, have been described. «δ»-Anhydro-digitoxigenin represents the thermodynamically most stable isomer. In this isomer the double bond in position 8 is unaffected by hydrogenation with Pt in acetic acid; with perbenzoic acid an epoxide results from which, on hydrogenation, the double bond can be regenerated in its original position. Analogous reactions are known to occur in the 8:14-epoxides.     

化“材”为“筑”

Chemistry is a central, practical and creative discipline. The development of chemistry plays an important role in the progress of science and society, as well as the improvement of the quality of human life. This paper introduces the chemical knowledge of stone, concrete, glass and other inorganic nonmetallic building materials by the anthropomorphically story. Taking nanomaterials as an example, the prospect of building materials development in the future is put forward.     

Making "wheels" and "cubes" from triangles

[Mn(IV)Mn(II)3] triangular units directed by the presence of tripodal alcohols self-assemble in the presence of azide and acetate ligands to form either a [Mn24] "wheel" or a [Mn32] "cube".     

"Turn-on" fluorescent sensing with "reactive" probes

Chemical probes are valuable tools for the investigation of biochemical processes, diagnosis of disease markers, detection of hazardous compounds, and other purposes. Therefore, the development of chemical probes continues to grow through various approaches with different disciplines and design strategies. Fluorescent probes have received much attention because they are sensitive and easy-to-operate, in general. To realize desired selectivity toward a given analyte, the recognition site of a fluorescent probe is designed in such a way to maximize the binding interactions, usually through weak molecular forces such as hydrogen bonding, toward the analyte over other competing ones. In addition to such a supramolecular approach, the development of fluorescent probes that sense analytes through chemical reactions has witnessed its usefulness for achieving high selectivity, in many cases, superior to that obtainable by the supramolecular approach. Creative incorporations of the reactive groups to latent fluorophores have provided novel chemical probes for various analytes. In this feature article, we overview the recent progress in the development of turn-on fluorescent probes that are operating through chemical reactions triggered by target analytes. Various chemical reactions have been implemented in the development of many reactive probes with very high selectivity and sensitivity toward target analytes. A major emphasis has been focused on the type of chemical reactions utilized, with the hope that further explorations can be made with new chemical reactions to develop reactive probes useful for various applications.     

"Decoking" of a "coked" zeolite catalyst in a glow discharge

'Decoking' of a 'coked' zeolite catalyst in a glow discharge in oxygen is investigated. The 'decoking' process involves reactions of atomic oxygen (O atoms) with 'coke' and yields gases such as CO, CO₂ as well as other gaseous products that could be easily pumped out.Three different modes of discharge were investigated including a static mode, a flowing-gas mode, and a periodic-purge mode where the oxygen and other gaseous products of the discharge were replaced by fresh O₂ gas after short but regular intervals of time. In some cases, additional heating was also used to provide base temperatures of the order of 100 °C to facilitate penetration of oxygen atoms into the inner layers and cages of the zeolite catalyst.This paper presents some results of spectroscopic analytical techniques used to monitor the atomization of oxygen, oxidation of 'coke', and to confirm the process of 'decoking'. More specifically, radiation emission on the 3 s ⁵S– 3p ⁵P transitions of O around 777.2–777.5 nm were selected for monitoring the atomization of O₂. On the other hand, X-ray photo-electron spectroscopy (XPS) was used to determine the amount of residual carbon and extent of 'decoking'. Furthermore, evolution of CO and CO₂ gases as a function of time was systematically monitored in real time. For CO, the 451.1 nm band head belonging to the B¹ - A¹ bands of the Angstrom system of the CO spectrum was used, while for CO₂, the band head at 353.4 nm belonging to the CO₂⁺ spectrum was used. The rates of evolution of CO and CO₂ were related to the rate of 'decoking' of the catalyst. It is noted that in the periodic-purge mode, about 63% of the total yield of CO from a given sample of the catalyst appears in the first 3-min exposure to discharge whereas it takes up to 15 min to remove nearly 94% of the removable carbon under our experimental conditions.     

营养化学课程翻转课堂的探索与实践

With its tailored learning content, flexible learning environment and directed teacher guidance, the flipped classroom in "nutrition chemistry" has effectively solved the problems of students' specialty, large number and limited time in the course of elective course. The teaching mode based on the cultivation of students' ability and the core of improving scientific literacy was constructed.     

梦萦魂牵--《化学通报》复刊30年

哲学家和物理学家都喜欢研究和讨论“时间” ,时间之矢告诉人们光阴冉冉不复返 ,矢者失也。然而人们却总想回忆 ,寻找那些美好的或沮丧的过去 ,是安慰或自娱吧。我一直相信生活总是向前的 ,社会总是进步的 ,就和宇宙不停地膨胀一样。《化学通报》复刊已经 3 0年了 ,既然是复刊 ,必然先有停刊。历史总是把破坏和重建放在一起考虑的 ,才能找出规律。人们都说 2 0世纪是自然科学大发达的时代 ,然而 2 0世纪又是人类社会灾难最多的时代。正因如此 ,才促使科学多极化地、多样性地发展起来 ,从欧洲到美洲到亚洲 ,一点点 ,慢慢地扩散开来 ,也许 ,真…     

Size evolution study of "molecular" and "atom-in-cluster" polarizabilities of medium-size gold clusters

A study on static polarizabilities for a family of gold clusters (Au(n), n = 6, 12, 20, 34, 54) is presented. For each cluster, a density functional theory perturbation theory calculation was performed to compute the cluster polarizability and the polarizability of each atom in the cluster using Bader's "quantum theory of atoms in molecules" formalism. The cluster polarizability tensor, α(cluster), is expressed as a sum of the atom-in-molecule tensors, α(cluster)=∑(Ω)α(Ω). A strong quadratic correlation (R(2) = 0.98) in the isotropic polarizability of atoms in the cluster and their distance to the cluster center of mass was observed. The cluster polarizabilities are in agreement with previous calculations.