Effects of B-ionizing radiation on the properties of flexible packaging materials

The influence of B-ionizing radiation on chemical structure and mass transfer phenomena was studied in the principal flexible food packaging materials (LDPE and OPP). No significant changes were observed in the structure of polymer matrices or in oxygen permeability and global migration after ionizing the materials at dose levels approved for food products ( < 110 kGy). Nevertheless, at low doses, it was observed that volatile organic compounds were present in ionized films. Several oxidation products were analysed by a dynamic head space technique. These oxidation products (typically ketones, aldehydes and carboxylic acids) could play a part in the organoleptic properties of prepackaged foods and, consequently, in their shelf-life.     

辐照对常见塑料食品包装材料物理化学性能的影响

目的 辐照是食品行业中主要的消毒灭菌技术之一,通过系统综述国内外学者关于塑料食品包装材料辐照前后的变化,探究辐照技术对其物理化学性能的影响。方法 介绍食品辐照技术及其发展过程,重点分析辐照对常见塑料食品包装材料的辐解行为、迁移行为及物理性能的影响。结果 许多学者的研究都证明辐照会对塑料包装材料的光学、热学、力学性能及阻隔性等产生一定的影响,并导致降解产物的出现。结论 辐照对塑料食品包装材料的性能存在一定影响,需考虑材料辐照后在食品安全和物理性能方面的变化,且相关的法律法规尚有完善空间。     

塑料药物包装材料可提取物全景分析方法概述

目的 对国内常用的塑料药物包材的挥发性、半挥发性、非挥发性物质及金属元素等提取物质的检测和分析方法进行总结,为塑料药物包材可提取物质全景分析和安全性评价提供参考。方法 通过检索国内外相关文献,对塑料药物包材中不同可提取物的分析方法进行总结和归纳。结果 目前,国内塑料药物包材日益更新,但可提取物的分析手段单一、检测分析方法不全面,缺乏相应的数据库。结论 药物包材的相容性研究在国内起步不久。针对目前存在的塑料包材可提取物的分析手段单一、不全面,缺乏相应的数据库等问题,现阶段亟需构建分辨率和灵敏度高、特异性强、筛查范围广的方法,对药物包材可提取物质进行全景分析,减少因包材安全性不良引起的医疗事故。     

Polyvinyl chloride and its organotin stabilizers with special reference to packaging materials and commodities: A review

Polyvinyl Chloride (PVC) is a thermoplastic that has entered practically all areas of life as a cheap and versatile material. Since PVC also fulfils the high quality requirements placed on modern packaging materials, with respect to packaging techniques and consumer protection, it is being used to an increasing extent for packaging of food and beverages as well as pharmaceutical and cosmetic products. The various additives required for processing PVC into packaging materials and commodity articles, as well as improving its properties during usage (e.g. lubricants and stabilizers), are harmless with regard to human and ecotoxicological aspects. Their use is non-hazardous and is therefore permitted by authorities. In the group of thermo- and light stabilizers for PVC, mixtures of mono- and dialkyltin thioglycolates play a major role. In accordance with legislation, these are allowed to be used in rigid PVC. In addition to their excellent stabilizing effect, they are not hazardous to the health of consumers of products packed in rigid PVC. Similarly, no health hazards exist to personnel, working in PVC production and processing plants, from volatile components of organotin stabilizers provided that processing and environmental prerequisites of modern technology are observed. The disposal of household waste that contains used PVC materials — stabilized with mixtures of mono- and dialkyltin thioglycolates — does not cause additional difficulties.     

γ-Radiolysis of Polyynes in Heptane

The polyynes in heptane solution were γ-radiolyzed at a total dose of 150, 300 and 600 kGy. After radiolysis the products were analyzed by electronic absorption spectroscopy, by HPLC (liquid chromatography) and by FT-IR spectroscopy. Even at 150 kGy the polyynes disappear completely from the solution and the chromatographic analysis shows that the acetylenic chains undergo fragmentation, addition and crosslinking reactions with other chains and with solvent. The oxidative interference from air has been detected by FT-IR.     

The effect of ionizing radiation on metoprolol

The influence of ionising radiation on physico-chemical properties of metoprolol tartrate (MT) in solid phase was studied. The compound was irradiated by radiation produced by a beam of high-energy electrons in an accelerator, in doses from 25 to 400 kGy, and the possible changes in the samples were detected by organoleptic analysis (colour, forms, clarity), chromatographic and spectrometric methods. Already at the standard sterilisation dose of 25 kGy, the presence of free radicals (0.3764 × 10¹⁶ spin/g) and a decrease in the melting point by 1°C were noted. At higher doses of irradiation products of radiolysis appeared (100 kGy) and the colour was changed from white to pale cream (200 kGy). Our observation was that with increasing mass loss of MT after irradiation with 100, 200 and 400 kGy, the concentration of free radicals increased from 1.0330 to 1.6869 × 10¹⁶ spin/g. The radiolytic yield of total radiolysis was 4.54 × 10⁷ mol/J for 100 kGy, 7.42 × 10⁷ mol/J for 200 kGy and 4.74 × 10⁷ mol/J for 400 kGy. No significant changes were observed in the character of FT–IR spectra, but in UV an increase in intensity of the band at the analytical wavelength was noted. As follows from the results MT shows high radiochemical stability for the typical sterilisation doses 25–50 kGy, and will probably be able to be sterilised by radiation in the dose of 25 kGy.     

不同包装材料对酱肉挥发性风味物质的影响

目的 研究酱肉在PET/AL/PE铝箔包装、PET/PE透明包装条件下不同时间段的挥发性风味物质的变化。方法 采用顶空固相微萃取–气相色谱–质谱连用法(SPME–GC–MS)并结合相对气味活度值(ROAV)、主成分分析(PCA)对酱肉挥发性风味物质变化进行分析。结果 研究发现,酱肉中挥发性物质主要为酯类、醇类,其中苯甲酸乙酯、乙酸芳樟酯、癸酸乙酯、正己酸乙酯、(+)–柠檬烯、壬醛、正己醛、(–)–4–萜品醇、桉叶油醇、芳樟醇、乙基麦芽酚、茴香脑的ROVA值大于1,为关键风味物质。PCA分析得出,2–甲基丁酸乙酯、(E,E)–2,4–壬二烯醛、正己酸乙酯、2,5–辛二酮、(1R)–2,6,6–三甲基双环[3.1.1]庚–2–烯、3–甲硫基丙醛、异丁酸乙酯、茴香脑为特征性挥发性风味物质。另外,通过对在PET/AL/PE铝箔和PET/PE透明包装下,酱肉各类风味物质含量、主体香味物质和异味物质ROVA值、主成分分析的比较,说明不同包装材料对酱肉挥发性风味物质的成分、含量均有影响。结论 从长期检测的结果看出,PET/AL/PE铝箔包装比PET/PE透明包装可显著地阻止脂肪氧化,较少生成异味物,可更好地保护酱肉的香味,为酱肉的贮藏保鲜提供了依据。     

纸质食品包装制品中挥发性MOSH组分SPME-HSGC-MS追踪检测

目的 对一次性纸质食品包装制品(盒、袋、桶、杯等)中挥发性饱和烃矿物油(MOSH)组分的含有情况进行检测分析，以确定纸质食品包装材料及制品中各挥发性MOSH组分向外挥发的性能以及对所包装食品(食品模拟物)的潜在危害性。方法 将样品裁切(5 mm×5 mm)后，取适量样品采用固相微萃取法进行萃取富集，然后使用顶空气相色谱-质谱进行检测，通过NIST质谱库检索、特征离子碎片检索以及标准样品比较相结合的方法进行定性。同时，为确定各样品中挥发性MOSH组分的迁移性能，在时隔6个月之后，对以上样品采用同样的方法进行取样、检测、分析。最后，根据2次检测的结果，判断市售一次性纸质食品包装材料及制品中挥发性MOSH组分的迁移性，以确定其对食品安全性的影响情况。结果 结果表明，所测的16种样品中均含有挥发性MOSH组分，并且其含量随着时间而降低;同时发现，没有印刷图文或印刷图文面积极小的纸质包装制品中挥发性MOSH组分向外迁移的速度较低。结论 SPME-HSGC-MS适用于纸质包装材料或制品中挥发性(半挥发性)MOSH组分的检测与分析。为降低由纸质食品包装材料及制品中挥发性MOSH组分对人体产生的危害性，建议纸质包装材料或制品制作完成后，在不增加仓储压力的情况下，放置一段时间，并加大其存储空间的通风，再用于食品包装。     

Contamination of Polyvinyl Chloride Cling Films from Cardboard Packaging

An analytical screening was undertaken with the aim of investigating the occurrence of di‐isobutylphthalate (DIBP) in polyvinyl chloride (PVC) cling films for food contact applications and its source of contamination throughout a converting process. Although raw plastic materials used by producers are free from phthalates and analytical evidences confirm their absence after the extrusion process, DIBP can be found in final rolls packaged into cardboard packaging during storage. A solvent extraction Gas Chromatography/Mass Spectrometry (GC/MS) analysis was applied on several intermediate products and at different stages taken from the converting process, with the aim of identifying the source of contamination. Different cardboard cores and folding cardboards made of recycled fibres were analyzed, and some of them resulted highly contaminated by DIBP. The storage of final cling films with these materials increased DIBP transfer into PVC. To investigate the possible DIBP transfer mechanism from contaminated paper and adsorption by plastic materials through the gas phase, kinetic experiments were performed in a model system. Results obtained at 20 °C, 30 °C and 40 °C showed a considerable uptake of DIBP into PVC; Weibull model parameters estimated from the experimental data suggested an initial rate of the process dependent on temperature. In addition, to evaluate the partitioning behaviour, adsorption isotherms of DIBP into paper, PVC and low low density polyethylene (LLDPE) cling film were obtained at 40 °C. Copyright © 2012 John Wiley & Sons, Ltd.     

The Effect of High Pressure Processing on the Integrity of Polymeric Packaging – Analysis and Categorization of Occurring Defects

As high‐pressure processing is used increasingly for the treatment of packed products, different packaging has been investigated with respect to their structural behaviour and stability under high‐pressure processing. Often, failures and changes of the polymeric structure occur. Common damage symptoms of high‐pressure‐treated packaging materials are defined and classified in this review. These damage symptoms are allocated to the physico‐chemical effects that created them. The effects may be separated into direct effects induced by the action of the high‐pressure alone and indirect effects that are mediated via compressed contents of the package, i.e. filled product and gaseous headspace. The direct effects split up again in reversible and irreversible structural changes. The indirect effects are generated by compressed headspace gases, other compressed substances and the consequences of increased amounts of gases dissolved in the polymers. If applicable, current theoretical approaches have been allocated to the different categories of damage. Copyright © 2013 John Wiley & Sons, Ltd.     

绿色包装新材料——BOPET-G热收缩薄膜的应用趋势

随着经济发展和消费的多样化,包装材料的结构也发生变化。绿色包装产品有极大的市场潜力。2011年3月27日,国家发改委令第9号《产业结构调整指导目录(2011年本)》规定,淘汰"直接接触饮料和食品的聚氯乙烯(PVC)包装制品"、限制聚氯乙烯(PVC)食品包装膜。随之而来的是高性能有机高分子复合材料的研发,推广应用,以便取代PVC包装材料,达到食品药品包装的环保和无毒无害化。     

口服固体制剂常用包装材料及容器的研究进展

目的 为不同口服固体制剂准确选用合适包装容器提供理论参考和现实依据。方法 从口服固体制剂常用包装容器的原材料和辅料特性入手,通过解析不同包装容器的技术要求,介绍国内药品包材审评制度和现阶段国家药监局药品审评中心药用包装材料登记数据,对口服固体制剂不同包装容器的特点和使用进展进行综述。结果 对剂量要求精准、单日服用剂量较小的制剂宜选用单剂量独立包装的泡罩包装;对需长期用药、单日服用剂量较大的药物宜选用塑料瓶包装;颗粒剂和散剂多选用复合膜、袋包装;包装规格较大但不宜用塑料瓶包装的芳香性、油脂性、挥发性及易氧化药物,可选用玻璃瓶包装。结论 药品生产企业在选择药品包装时,应结合包装原材料物化性质、与承装药品相容性、力学性能、装量范围、携带使用方便性和价格成本等多方面因素,综合考虑选择合适的包装容器,以保证药品质量稳定和安全有效。     

石墨烯/环氧树脂复合涂层的γ射线辐照损伤及其腐蚀防护性能

用硅烷偶联剂对石墨烯表面进行修饰, 制备石墨烯/环氧树脂复合涂层。通过交流阻抗(EIS)和塔菲尔极化曲线(Tafel slope)等电化学方法分析复合涂层经伽马射线辐照后的腐蚀防护性能。采用电子自旋共振(ESR)和傅里叶红外光谱分析仪(FTIR)等测试复合涂层的γ射线辐照损伤, 探索了石墨烯在环氧树脂中抗辐照损伤的作用机理。Tafel结果显示复合涂层经280 kGy辐照后, 腐蚀电流为6.140×10^-9 A/cm², 而纯环氧树脂涂层的腐蚀电流则为1.340×10^-8 A/cm², 说明石墨烯可以使复合涂层保持较好的腐蚀防护性能。ESR分析表明, 复合涂层中的石墨烯可以降低环氧树脂基体在γ射线辐照过程中产生的过氧自由基, 表明石墨烯可有效吸收辐照过程中的自由基。辐照前后复合涂层的FT-IR图谱没有发生明显变化, 说明石墨烯有效降低了伽马射线对环氧树脂的结构损伤。因此, 可以认为石墨烯能够减缓环氧树脂在高能辐照环境中的老化, 从而延长其使用寿命。     

高能电子束辐照对NBR/PVC胶圈胶料性能的影响

采用高能电子束对丁腈橡胶/聚氯乙烯(NBR/PVC)胶圈胶料进行辐照,研究不同辐照剂量对NBR/PVC胶圈胶料性能的影响。实验结果表明,生橡胶经高能电子束辐照后,焦烧时间随辐照剂量增大逐渐减小;NBR/PVC硫化胶经高能电子束辐照后,冲击弹性提高33%~67%,硬度提高4%~10%,拉伸强度提高8%左右,断裂伸长率下降6.7%~34.4%。单因素试验结果显示,50k~60kGy剂量辐照时,硫化胶拉伸强度提高幅度较大,压缩、拉伸永久变形和磨耗量下降,同时弹性、硬度均有提升。综合考虑,50k~60kGy剂量为辐照NBR/PVC胶圈硫化胶的最适剂量。     

A proposal to establish ‘packaging science’

To make packaging truly beneficial to human beings, it is important to help people learn more about the great variety of packaging materials and packaging techniques. In applying that knowledge, certain ethics should be observed by those engaged in packaging activities. The first step in achieving this task is to recognize what constitutes the packaging sciences, and from the results of various investigations a system of packaging sciences has been produced. Packaging science, as we have organized it, consists of the three major fields of packaging sociology, packaging materials science and packaging technology. With regard to the ethics that should form the backbone for the varied packaging activities, we propose that a Packaging Charter be established, incorporating the basic spirit and the ideas outlined herein.     

Effect of light and oxygen transmission characteristics of packaging materials on photo‐oxidative quality changes in semi‐hard Havarti cheeses

Changing transmission characteristics of food packaging materials by colouring the materials may be a suitable way of reducing photo‐oxidative quality changes. This study proved that packaging in black laminates provided the best protection of Havarti cheese, followed by a white laminate. However, transparent packaging materials did not protect the product in the critical wavelength range, i.e. 400–500 nm, and changes in colour and odour were already notable after few hours of exposure to fluorescent light. Additionally, secondary oxidation products, hexanal, 1‐pentanol, and 1‐hexanol, were formed in cheese packaged in transparent or semi‐transparent packaging materials. The expected effects of oxygen transmission were difficult to evaluate, due to high residual oxygen levels in the packages. Copyright © 2002 John Wiley & Sons, Ltd.     

Structural and morphological changes in Poly(caprolactone)/poly(vinyl chloride) blends caused by UV irradiation

Films made from a blend of poly(ε-caprolactone) and poly(vinyl chloride) (PCL/PVC) retained high crystallinity in a segregated PCL phase. Structural and morphological changes produced when the films were exposed to high potency ultraviolet (UV) irradiation for 10 h were measured by UV-Vis spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). They were different to those observed with homopolymer PCL and PVC films treated under the same conditions. The FTIR spectra of the PCL/PVC blend suggest that blending decreased the susceptibility of the PCL to crystallize when irradiated. Similarly, although scanning electron micrographs of PCL showed evidence of growth of crystalline domains, particularly after UV irradiation, the images of PCL/PVC were fairly featureless. It is apparent that the degradation behavior is strongly influenced by the interaction of the two polymers in the amorphous phase.     

Effect of electron beam treatments on degradation kinetics of polylactic acid (PLA) plastic waste under backyard composting conditions

The effects of electron beam irradiation on backyard composting behaviour of polylactic acid (PLA) polymer were evaluated. Samples (10 mm² × 0.75 mm) from thermoformed PLA drinking cups were exposed to 10 MeV electron beam irradiation at doses of 0, 72, 144 and 216 kGy. Irradiated PLA samples were placed in heat‐sealed, plastic screen and added to organic feedstock in a rotating composter within a computer‐controlled environmental chamber for 10 weeks at 35°C. Changes in weight, structural integrity and molecular weight were assessed over time. Results show that irradiation enhanced PLA breakdown. PLA weight decreased by increasing amounts as irradiation dose increased. Sample brittleness increased with irradiation dose and composting time. Finally, PLA molecular weight decreased as irradiation dose and compost time increased. Molecular weight D values for irradiated PLA were found to be about 430 kGy. After 1 week in a typical backyard composter, molecular weight D values increased to about 560 kGy and then fell to about 380 kGy after 2 weeks of composting. Samples irradiated at 216 kGy showed a reduction in weight of 9.4% after 10 weeks of composting, and a reduction of weight‐average molecular weight of 93.7% after 6 weeks. Copyright © 2008 John Wiley & Sons, Ltd.     

基于g–C3N4光催化型抗菌包装纸的制备及其抗菌性研究

目的 解决g–C3N4存在的比表面积小，电子–空穴复合速率快从而导致光催化性能不佳等问题。方法 以尿素和硫脲为前驱体材料，通过热解聚辅助水蒸气活化合成S掺杂石墨相氮化碳(g–C3N4)，并用界面聚合制备出光催化型抗菌包装纸。利用扫描电镜(SEM)、红外光谱(FTIR)、水接触角(WCA)、热重分析(TGA)、光催化抗菌实验等对抗菌包装纸的形态结构、表面官能团、纸张性质、光催化抗菌性进行详细研究。结果 致密的g–C3N4层有效提高了抗菌包装纸的疏水性和热稳定性。可见光照射下，光催化型抗菌包装纸对大肠杆菌和金黄色葡萄球菌的杀灭率达100%。未经可见光照射的原纸比光催化型包装纸的抗菌性差。结论 g–C3N4光催化型抗菌包装纸具有良好的广谱抗菌性，为绿色抗菌包装材料的制备提供了新思路。     

Effects of electron beam irradiation on antioxidants in commercial polyolefins: Determination and quantification of products formed

The influence of electron beam irradiation on antioxidants present in food packaging materials (OPP and LDPE) was studied. After irradiating the materials at dose levels of 2, 5,10 and 25 kGy, we have shown a partial disappearance of the antioxidant (Irganox 1010, Irganox 1076 and Irgafos 168) and a release of three compounds resulting from the antioxidants degradation related to the irradiation dose. Two of these degradation compounds have been analysed quantitatively: the 2,4-di-tert.-butyl-phenol and the 2,6-di-tert -butyl-p-benzoquinone. The third compound is a phosphate resulting from a phosphite stabilizer (Irgafos 168).