Modelling of simultaneous two-sided migration into water and olive oil from nylon food packaging

Nylon 6 and nylon 12 food packaging materials used as sausage casings are typically exposed to fatty food on one side and boiling water on the other during the cooking process. To simulate the migration behaviour under these conditions, a special migration cell was constructed and filled with olive oil on one side of the polymer and water on the other to find out what amounts of the migrants will transfer to either side and phase at 100 °C. Results show that when a nylon 6 film is exposed to the conditions as described above, total mass transfer of the monomer—caprolactam—into the water phase occurs after 2 h at 100 °C. Nylon 12 sausage casings release similar amounts of their monomer—laurolactam—into both the aqueous and oil phase. An existing computer migration model was adapted to simulate the situation of simultaneous two-sided migration applying previously determined diffusion and partitioning coefficients. The suitability of the model was confirmed by experimental data.     

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.     

水产品活性包装和智能包装技术的研究进展

水产品贮藏品质对加工保藏技术的要求以及国内消费者对水产品加工食品质量安全的存疑促进了水产品活性包装和智能包装技术的发展。活性包装技术通过包装材料吸收不利保藏的成分,或释放有利保藏的成分,或发挥涂膜抗菌、抗氧化作用,对水产品起到防腐保鲜的作用。智能包装技术通过标签指示剂、信息溯源提高产业链管理效率以及减少消费者对水产品品质和安全的担心。虽然国内外在水果、蔬菜、奶制品等食品上已有新包装技术的应用,但是我国水产品活性包装和智能包装的工业化尚在起步阶段。本文总结了主要的活性包装和智能包装技术,并总结了新包装技术在国外水产品上的应用,以期为我国未来水产品新包装的发展提供借鉴参考。     

Kinetic migration studies from packaging films into meat products

One of the main concerns regarding safety of food packaging is the possible migration of chemical substances (monomers and other starting substances, additives, residues) from food contact materials into foods. To evaluate the effect of the fat content and of the temperature of storage on the migration from plastics packaging films into meat products as an important class of foodstuffs, the kinetic mass transport of a model migrant (diphenylbutadiene) from low density polyethylene (LDPE) film in contact with different meat products was investigated. From the data, the diffusion coefficients were calculated for the applied test conditions, by use of a mathematical model. The results showed that migration increased with fat content and storage temperature. Analysis of migration data corresponding to minced pork meat containing different amounts of fat, stored for 10 days at 25°C, revealed an excellent relationship between migration level and fat content. This behaviour was also found for other types of meat products (chicken and pork neck). A simplifying mathematical model was applied to derive effective diffusion coefficients in the polymer which, however, do take kinetic effects in the meat also into account. In the case of pork meat contact, the effective diffusion coefficients derived from mathematical modelling were ten times higher for storage at 25°C (1.88×10(-9)cm(2)s(-1)) than for storage at 5°C (1.2×10(-10)cm(2)s(-1)).     

Evaluating the migration of ingredients from active packaging and development of dedicated methods: a study of two iron-based oxygen absorbers

The behaviour of two commercial oxygen-scavenging products with respect to migration of active ingredients into foodstuffs was investigated. Migrants were identified, and by using appropriate analytical methods, migration was determined in a variety of liquid, solid or gelled food simulants and foods. Simulants were chosen to cover a range of water activities and viscosities. Foods and the gelled food simulant agar were packed with and without vacuum, and with the oxygen scavenger in various locations relative to the packed food. The main migrants, as identified by X-ray fluorescence spectrometry, infrared spectroscopy and scanning electron microscopy with energy-dispersive spectrometry were Na + and Cl - in non-acidic aqueous simulants, and Na + , Cl - and Fe 2+ in 3% acetic acid. Migration into aqueous simulants exceeded the current European Union limit for total migration from plastic materials (assumed to be currently applicable to these systems) and was probably excessive by any reasonable standard. However, neither oxygen scavenger appeared to release significant quantities of migrants into solid foods when the scavenger was properly located in the package and the packing process does not favour the contents becoming wet by water released from the food.     

Effect of ionizing radiation on the physicochemical and mechanical properties of commercial monolayer flexible plastics packaging materials

The effect of γ-radiation doses (5, 10, 30 kGy) on the mechanical properties, gas and water vapour permeability, infrared (IR) spectra, and overall migration into aqueous and alternative fatty food simulants of commercial monolayer flexible packaging films ethylene vinyl acetate (EVA), high-density polyethylene (HDPE), polystyrene (PS), bi-axially oriented polypropylene (BOPP), low-density polyethylene (LDPE) and Ionomer was studied. For comparison purposes, respective non-irradiated (control) films were also studied. The results showed that radiation doses of 5, 10 and 30 kGy did not induce any statistically significant changes in the permeability of all studied films to gases (oxygen and carbon dioxide) and water vapour. Likewise, IR spectra of all studied films showed no significant differences after all absorbed doses. The mechanical properties (tensile strength, percentage elongation at break and Young's modulus) of all studied films remained unaffected after absorbed doses of 5 and 10 kGy. In contrast, the tensile strength of HDPE, BOPP and Ionomer films irradiated at a dose of 30kGy decreased. In addition, the percentage elongation at break of LDPE and Ionomer films irradiated at a dose of 30 kGy decreased while Young's modulus of all samples remained unaffected. All mechanical properties of PS and EVA films remained unaffected after radiation at 30 kGy. Radiation (all absorbed doses) resulted in no statistically significant differences in overall migration values into distilled water for all studied films. For 3% aqueous acetic acid, absorbed doses of 5 and 10 kGy did not affect overall migration values of all investigated samples with the exception of the Ionomer film, for which the overall migration value decreased at 10 kGy. An absorbed dose of 30 kGy caused an increase in BOPP overall migration values and a decrease in Ionomer overall migration values. In contrast, a dose of 30 kGy induced no changes in overall migration values of EVA, HDPE, LDPE and PS films into the same simulant. There were no statistically significant differences in overall migration values of EVA, PS and LDPE films into iso-octane for all absorbed doses. In contrast, a dose of 30 kGy resulted in an increase in overall migration values of BOPP and a respective decrease in HDPE and Ionomer films.     

Development and validation of analytical methods for ethyl carbamate in various fermented foods

The aim of this work was to develop and validate analytical methods for ethyl carbamate (EC) in various food matrices. Column chromatography was used for the analysis of EC in kimchi, a fermented soybean paste (doenjang), a fermented fish product (jeotgal), yoghurt, bread, and cheese. To remove the fat in the bread and cheese, a Florisil cartridge was selected. The volume of dichloromethane in the chromatography column was optimised to 60 mL for the kimchi, cheese, and fermented soybean paste. For the bread, jeotgal, and yoghurt, the best recovery rate was found by using 100 mL of dichloromethane. For the accurate analysis of EC in the vinegar, 150 mL of dichloromethane and a neutralisation process (pH = 8.0) were required. In the standard curve of EC, satisfactory linearity (R² = 0.998) was shown. The limit of quantification (LOQ) was 10 ng/mL and the recovery rates ranged from 76.9% to 118.1%. Intra- and inter-assay precision ranged from 3.5% to 34.2% and 3.8% to 41.9%, respectively.     

Analysis of food packaging UV inks for chemicals with potential to migrate into food simulants

Ultraviolet (UV) inks are an alternative formulation system to the more usual paste or liquid inks (oils or solvents based) that dry mainly by evaporation or penetration into the printed substrate. Based on acrylic acid chemistry, UV inks dry (the exact term is 'curing') by the chemical process of photopolymerization. Their composition (acrylate monomers and oligomers together with photo-initiators) exposed to UV emission lamps on the printing press units enable the transformation of the freshly printed ink layer into a tack-free film. For UV inks intended for primary food packaging, special care has to be paid to potential migrating species like small photo-initiator molecules and acrylate monomers not cross-linked in the formed network. The paper presents chromatographic methods to ascertain the level of ink ingredients potentially available to migrate into food simulants (migration tests). GC/MS was employed to quantify the levels of photo-initiators or acrylic esters (acrylates).     

A study on the migration of organic pollutants from recycled paperboard packaging materials to solid food matrices

Paper and board are widely used as food packaging materials, mainly for disposable products. As public interest in conservation of natural resources has accelerated in the past several years, the use of recycled paper and board has increased. Recycled fiber materials can be used in certain limits as food contact materials. The safety of recycled fiber-based materials for food contact applications is largely dictated by the ability of post-consumer contaminants to be absorbed into recycled materials and later released by the packaging material and trapped on the food. The present work was undertaken with the aim of investigating the physicochemical behavior of selected model contaminants on paper and board, in contact with foodstuffs thus producing a fundamental set of data about their mobility from recycled paper and board into foods. More specifically, the kinetics of migration of selected model contaminants (surrogates) from contaminated recycled paper packaging samples into dry foodstuffs with different fat content was studied using a method based on solvent extraction and GC-FID quantification. Results showed the ability of selected contaminants of various types and various volatilities to potentially transfer to dry foods. The proportion of substances migrated to food was strongly dependent on the nature of the paper samples, fat content of the food, chemical nature and volatility of the migrant. The highest level of migration of organic pollutants was observed for the substrate with the highest fat content. Furthermore, it is shown that contact time and temperature have a significant effect on migration of model contaminants into foods.     

塑料食品包装材料中有毒有害化学残留物及分析方法

食品包装材料中有毒有害化学物质的迁移是引起食品污染的重要途径之一。本文主要根据近年来发表的有关食品包装材料、卫生检测领域的相关文献为基础,针对塑料食品包装材料中的单体、低聚体、添加剂和污染物等几类有毒有害化学物质的组成、毒性、卫生限量标准及主要检测方法进行了分析,为相关食品包装企业的质量控制技术人员和科研工作者提供参考。     

Evaluation of some screening methods for the analysis of contaminants in recycled polyethylene terephthalate flakes

A range of different analytical techniques were used to test recycled polyethylene terephthalate (PET) flakes for potential chemical contaminants. The techniques used were headspace gas chromatography coupled to mass spectrometry (GC-MS), liquid extraction followed by GC-MS, supercritical-fluid extraction followed by GC-MS, and migration testing followed by elemental analysis using inductively coupled plasma mass spectroscopy (ICP-MS). The PET samples were 50 representative samples taken from 600 that had been collected throughout Europe and which had been screened for potential contaminants using a single technique of high-temperature GC-MS. Six of the 50 samples tested had been spiked with a selection of model contaminants, three samples were virgin PET flakes and two of the samples were from supercleaning processes. All samples were analysed 'blind' in this exercise. The qualitative results showed that most of the contaminants came from the first use, being flavour-aroma compounds from soft drinks. The quantitative analysis found concentrations under a few mg kg^-1 in the polymer, except for the spiked samples. Element migrations were low and only calcium, silicon and sodium had median migrations above 50 μg l^-1. This in-depth analysis of recycled PET flakes did not identify any significant contaminants that had not already been detected by the high-temperature static GC-MS screening method, thus demonstrating its utility.     

Migration of additives from polymers into food simulants: numerical solution of a mathematical model taking into account food and polymer interactions

The principle of a computing program describing precisely the migration of additives from a polymer into a food simulant is presented. As six parameters are used to fit the simulant sorption and additive extraction kinetics, the parameters have been determined by independent experiments. Owing to the complicated coupling between the liquid and additive diffusion processes, migration kinetics cannot be obtained by a mathematical resolution of kinetic equations, but they must be calculated by numerical analysis. The method is applied to a UV absorber in polypropylene migrating into glyceryl tripelargonate, a pure triglyceride, of which behaviour and average molecular weight are similar to official fatty food simulants. Properly designed experiments validate the model used to fit the migration kinetics. The possibility of erasing any parameters is also discussed.     

Polymer additive migration to foods - a direct comparison of experimental data and values calculated from migration models for high density polyethylene (HDPE)

To reduce the amount of compliance testing for food contact polymers the use of migration modelling has been proposed. This study was conducted to provide valid data for the independent evaluation of two such diffusion-based models using a range of different high density polyethylene (HDPE) polymers and plastics additives. Seventy-two experimental migration data have been obtained in triplicate and used to evaluate two Fickian-based migration models in the prediction of specific migration of four HDPE additives into olive oil. All tests were conducted using olive oil, representing the most severe case for fatty foods with test conditions of 2h at 70oC, 6h at 70oC, 10 days at 40oC representing short term exposures at high temperatures and room temperature storage. Predicted migration values were calculated by inserting the measured initial concentration of additive in the polymers (Cp,0) into the equations together with known variables such as additive molecular weight, temperature and exposure time. The results indicate that both models predict migration values into olive oil close to, or in excess of, the experimental results. The Piringer migration model, using the 'exact' calculations of the Migratest Lite program, gave an overestimation for 83% of the migration values generated in this study. The highest overestimation was 3.7 times the measured value. For all measurements, the predicted migration from the Migratest Lite program was greater than 50% of the observed value. The FDA model was found more accurately to predict migration in most situations but underestimated migration more frequently. Differences in the polymer specification had little effect on specific migration of the additives investigated.     

Crossmodal correspondences between taste and shape,and their implications for product packaging: A review

A growing body of empirical research now demonstrates that people associate different basic tastes and taste words with specific packaging shapes. While it may be obvious that semantic knowledge concerning products, based on the packaging and/or design elements (e.g., typeface, logo, label, images), can guide the taste expectations that consumers generate in relation to a given product, here we demonstrate that there are also more fundamental correspondences that operate even with unfamiliar stimuli. Specifically, shape features (e.g., straight vs. curvy, or symmetrical vs. asymmetrical) have been shown to influence the taste that people naturally associate with a given shape. The evidence suggests that, at least to a certain extent, people match such shape dimensions with tastes on the basis of their common affective connotation. Here, we critically review the literature on these seemingly arbitrary, yet systematic, crossmodal correspondences between tastes and shape features. We suggest that they can inform the design process when it comes to product packages and labels with the aim of conveying taste information more effectively. This review is relevant to those researchers interested in taste-vision correspondences as well as to food marketers, and those designers interested in the communication and influence of taste information.     

Polymer additive migration to foods-a direct comparison of experimental data and values calculated from migration models for polypropylene

To reduce the amount of compliance testing for food contact polymers the use of migration modelling is under discussion and being evaluated by an EU Commission funded project (Evaluation of Migration Models No. SMT4-CT98-7513). The work reported in this paper was exclusively funded by industry to provide data for the independent evaluation of a diffusion based model using eight different samples of polypropylene (PP) covering the range of polymers specification and five commonly used plastics additives. One hundred and fifty experimental migration data have been obtained in triplicate and used to evaluate a Fickian-based migration model in the prediction of specific migration of five additives into olive oil. All tests were conducted using olive oil, representing the most severe case for fatty foods, with test conditions of 2h at 121 ° C, 2h at 70 ° C and 10 days at 40 ° C, representing short term exposures at high temperatures and room temperature storage. Predicted migration values were calculated using the Piringer 'Migratest Lite' model by entering the measured initial concentration of additive in the polymers(C_p,0) in to the equations together with known variables such as additive molecular weight, temperature and exposure time. Where necessary the data generated in this study have been used to update the model. The results indicate the Piringer migration model, using the 'exact' calculations of the Migratest Lite program, predicted migration values into olive oil close to, or in excess of, the experimental results for > 97% of the migration values generated in this study. For all measurements, the predicted migration from the Migratest Lite program was greater than 70% of the observed value. This study has identified the possibility that random co-polymers of propylene and ethylene give higher migration than other grades of polypropylenes and could be treated as a separate case. However, further work on more samples of random co-polymers is required to confirm this finding.     

Influence of semi-solid fluid’s surface tension and rheological properties on the residues at packaging materials

Residues of food are unwanted in food processing and food packaging. Therefore different properties of high viscous food and their relevance to adhesion phenomena at packaging surfaces are investigated herein. The results may be utilised to reduce the amount of sticking content.In order to quantify the amount of remaining material a method of evaluation was designed using polysaccharides solutions and mixtures of highly viscous oils as model products. The surfaces tension and rheological properties were analyzed. The work of adhesion of each product-surface system was calculated from the respective contact angle data.It was found that the viscosity has a great influence on the amount of residues. For Newtonian liquids the influence is linear. For viscoelastic liquids there are other effects that cause fewer residues when the viscosity is increased. Furthermore, it seems that fewer residues remain when the dispersive part of the surface tension of the liquid is high. Aside from this the work of adhesion is a good measure to predict the amount of residue.     

食品包装用三聚氰胺成型品中甲醛迁移规律的研究

目的研究食品包装三聚氰胺成型品中甲醛迁移规律。方法采用盐酸苯肼分光光度法测定60、75和90℃三个模拟温度下甲醛从食品包装用三聚氰胺成型品中迁移至3%乙酸、15%乙醇两种模拟溶剂中的量。根据所得的实验数据,讨论了不同温度和不同食品模拟物的选择对甲醛迁移行为的影响,以及样本重复10次进行迁移实验时甲醛迁移量的变化规律。结果3%醋酸作为模拟溶剂的甲醛迁移量较15%乙醇作为模拟溶剂的高,且其迁移量随着模拟温度的升高而增多;3个温度下,2种模拟溶剂中单次迁移实验的甲醛迁移量均未超过我国国家标准的限量值和欧盟规定对其规定的特定迁移量(SML)2.5 mg.dm-2,而以3%醋酸作为模拟溶剂的甲醛的10次迁移实验的总量均超过欧盟对甲醛的特定迁移量。结论食品包装用三聚氰胺成型品不宜在酸性和高温条件下使用。     

欧美和日本等国食品包装材料膳食暴露评估方法的比较分析

本文介绍了美国、欧盟、日本和加拿大在开展食品包装材料暴露评估时采用方法的原理、所需资料和计算过程,并对各种方法的覆盖面、实用性、难易程度等方面进行了比较,分析各自优缺点,为建立适合于我国国情的食品包装材料暴露评估方法,制修订食品包装材料安全标准提供科学依据,同时为食品包装材料风险评估机构、监管部门以及相关行业、企业开展相关研究工作提供参考.