Safety by design of printed multilayer materials intended for food packaging

ABSTRACT

Printing inks are commonly used in multilayer plastics materials used for food packaging, and compounds present in inks can migrate to the food either by diffusion through the multilayers or because of set-off phenomena. To avoid this problem, the right design of the packaging is crucial. This paper studies the safety by design of multilayer materials. First, the migration from four different multilayers manufactured using polyethylene terephthalate (PET), aluminium (Al) and polyethylene (PE) was determined. The structural differences among materials such as the presence of inks or lacquer coatings as well as the differences in layers position allowed the study of a safety-by-design approach. Sixty-nine different compounds were detected and identified; 49 of them were not included in the positive list of Regulation EU/10/2011 or in Swiss legislation and 15 belong to Cramer class III, which means that they have a theoretical high toxicity. Some of the compounds related to ink composition were pyrene, a compound commercially used to make dyes and dye precursors and the antioxidant Irganox 1300. The application of external lacquers decreased the concentration of some migrants but also brought the potential for new migrants coming from its composition. A final risk assessment of the material allowed evaluating food safety for different food simulants and confirm it.     

Migration and sensory properties of plastics-based nets used as food-contacting materials under ambient and high temperature heating conditions

Overall migration from a wide range of commercial plastics-based netting materials destined to be used as either meat or vegetable packaging materials into the fatty food simulant isooctane or the aqueous simulant distilled water, respectively, was studied. In addition, sensory tests of representative netting materials were carried out in bottled water in order to investigate possible development of off-odour/taste and discoloration in this food simulant as a result of migration from the netting material. Sensory tests were supplemented by determination of the volatile compounds' profile in table water exposed to the netting materials using SPME-GC/MS. Test conditions for packaging material/food simulant contact and method of overall migration analysis were according to European Union Directives 90/128 (EEC, 1990) and 2002/72 (EEC, 2002). The results showed that for both PET and polyethylene-based netting materials, overall migration values into distilled water ranged between 11.5 and 48.5 mg l^-1, well below the upper limit (60 mg l^-1) for overall migration values from plastics-packaging materials set by the European Union. The overall migration values from netting materials into isooctane ranged between 38.0 and 624.0 mg l^-1, both below and above the European Union upper limit for migration. Sensory tests involving contact of representative samples with table water under refluxing (100°C/4 h) conditions showed a number of the netting materials produced both off-odour and/or taste as well as discoloration of the food simulant rendering such materials unfit for the packaging of foodstuffs in applications involving heating at elevated temperatures. GC/MS analysis showed the presence of numerous volatile compounds being produced after netting materials/water contact under refluxing conditions. Although it is extremely difficult to establish a clear correlation between sensory off-odour development and GC/MS volatile compounds' profile, it may be postulated that plastics oxidation products such as hexanal, heptanal, octanal and 2,6 di-tert-butylquinone may contribute to off-odour development using commercially bottled table water as a food simulant. Likewise, compounds such as carbon disulfide, [1,1'-biphenyl]-2-ol and propanoic acid, 2 methyl 1-(1,1-dimethyl)-2-methyl-1,3-propanediyl ester probably originating from cotton and rubber components of netting materials may also contribute to off-odour/taste development.     

Multi-analyte methods for the detection of photoinitiators and amine synergists in food contact materials and foodstuffs – Part I: HPLC-DAD screening of materials

The objective of this work was to develop a HPLC-DAD method suitable for the screening of food contact materials for a total of 63 monomeric and polymeric photoinitiators and amine synergists. Such multi-analyte methods are worthwhile for official control laboratories, where normally no information about the composition of the applied inks or varnishes on the printed or lacquered materials is available and thus target analyses are not feasible. The polymeric analytes were each separated in a multitude of substance peaks, which largely overlaid those of the other compounds. Thus, for 13 polymeric photoinitiators and amine synergists a hydrolysis method was developed that reduced the number of ultraviolet (UV) detectable peaks to only one. This allowed easier identification and – preliminary – semi-quantification of these polymeric substances with adequate limits of detection. The remaining 50 photoinitiators and amine synergists were combined in one HPLC-DAD method. But since many of these substances are structurally related, partly retention times and spectra did not differ significantly. Thus selectivity was enhanced by preparing a database containing all spectra and retention times of the investigated compounds. Furthermore, the retention times of those 50 substances were calculated relative to two internal standards to overcome variances of retention from run to run or due to matrix effects. The developed method was tested for the analysis of food contact materials. Extractions of these were performed with acetonitrile and partially the extracts were subsequently concentrated in a steam of nitrogen. Limits of detection of photoinitiators and amine synergists in concentrated packaging extracts were in the range between 0.02 and 5.5 µg dm^?2.     

HS-GC/MS method development and exposure assessment of volatile organic compounds from food packaging into food simulants

ABSTRACT

A simultaneous headspace-gas chromatography/mass spectrometry (HS-GC/MS) method was developed and validated to determine the migration of 12 volatile organic compounds (methanol, acetone, methylethylketone, ethylacetate, isopropylalcohol, benzene, toluene, ethylbenzene, xylene, cumene, propylbenzene, and styrene) from food contact materials into food simulants (water, 4% acetic acid, 50% ethanol, and n-heptane). The limits of detection and quantification were 0.007–0.201 mg L^?1 and 0.023–0.668 mg L^?1, respectively. The method was applied to 205 samples of paper/paperboard, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate. The estimated daily intake (EDI) was calculated using the migration results. Exposure assessments were carried out to compare the EDI to the tolerable daily intake (TDI); the results indicated that the EDI of styrene represented only a small percentage (8.0%) of the TDI. This analytical method will be a useful tool to examine levels of various volatile compounds migrating from food packaging to food simulants using HS-GC/MS method.     

Optimizing an electronic nose for analysis of volatiles from printing inks on assorted plastic films

Volatiles from inks present in food packaging films could pose a quality problem in food products. The food industry is interested in determining a single set of optimum values for the system parameters to maximize detection levels on assorted plastic packaging films. Volatiles from ink used on nine plastic food-packaging films were analyzed using an electronic nose with six resonating quartz sensors. A response surface analysis was used to determine if the system parameters (sample temperature, equilibration time, sensor temperature and pressurization time) significantly affected the detection levels of volatile compounds. Sample temperature, equilibration time and sensor temperature were significant (α=0.05) for each of the sensors and the optimum settings for these parameters to maximize detection levels were 80 °C, 20 min, and 40 °C, respectively. The results of this study indicate potential for this electronic nose to be used as a discriminatory tool in quality control for packaging films.     

纸包装油墨中增塑剂向奶粉的迁移

纸包装油墨中含有有毒有害物质并可通过包装材料迁移进入内装食品从而危害人体健康。模拟实际印刷条件制作真实油墨迁移单元,研究纸张胶印油墨中4种主要增塑剂（3种邻苯二甲酸酯类增塑剂和近年流行的环保增塑剂乙酰基柠檬酸三丁酯）向奶粉的迁移,考察其在100、70、50、25 ℃的迁移行为,探讨增塑剂的性质及其在纸张中的分布等因素对迁移行为的影响。结果表明：4种增塑剂的最大迁移率在6.7%～67.8%之间。纸包装油墨中增塑剂的迁移防护性能还有待提高。     

食品包装油墨迁移研究进展

食品安全越来越受到广泛关注,包装材料中油墨引起的食品质量问题频频发生,本文论述国内外包装油墨安全相关的法规及要求,总结国内外油墨迁移研究现状,为今后的食品包装油墨安全提供法律依据和实验指导。     

食品包装材料中有害物质迁移行为的研究进展

食品包装材料在食品安全中发挥了重要的作用。食品包装能有效地保护食品,防止变质,但其中化学物质的迁移,又会给食品质量和安全带来负面影响。因此,对食品包装材料中化学物质的迁移进行研究显得非常必要。本文综述了近几年食品包装材料中有害物质的检测分析、迁移规律以及传质模型;对主要被检物质所采用的检测方法进行了总结,并对塑料与纸基材料中物质的迁移规律和传质模型进行了对比;最后对食品包装材料未来的发展方向进行展望。     

Rapid multi-analyte quantification of benzophenone, 4-methylbenzophenone and related derivatives from paperboard food packaging

Photo-initiators are used in printing inks hardened with UV light and one of the most commonly used photo-initiators is benzophenone (BP). Recent notifications under the Rapid Alert System for Food and Feed have shown migration of 4-methylbenzophenone (4-MBP) from packaging into cereals. A specific migration limit exists for BP of 0.6 mg kg^?1 for its use as an additive in plastics. There is no specific European legislation covering cardboard boxes and/or printing inks for food contact use. However, due to the high levels detected, the European Food Safety Authority (EFSA) published recommendations and the Standing Committee for the Food Chain and Animal Health endorsed a limit of 0.6 mg kg^?1 for the sum of BP and 4-MBP. While studies have been published on photo-initiators in the past, there is a fundamental lack of data on 4-MBP especially for its combined analysis with others. We present an HPLC method with diode array detector to simultaneously determine the levels of BP, 4-MBP as well as 7 other possible derivatives from secondary packaging for food applications. The method was tested and applied to 46 samples of paperboard for secondary packaging collected both from supermarkets and directly from a paperboard supplier. In addition, a survey was conducted on recycled paperboard (n = 19) collected from a supplier, to evaluate the background quantity of BP and other derivatives in recycled board. The most abundant photo-initiator found in the survey was BP, in 61% of samples, and 4-MBP was found in 30% of the samples. It seems that these compounds are used to replace one another. Other derivatives were found in minor quantities. Traces of BP were also found in 42% of the samples of recycled, unprinted board.     

Experimental and theoretical study of LDPE: Evaluation of different food simulants and temperatures

The mass transfer process of additives from plastic packaging to food is of great importance and interest because of the possible harmful effects on the human health. In this work the effect of different food simulants (EtOH 10–50%) and temperatures (28–60 °C) on the specific migration of Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (I-1076) from LDPE films is experimentally and theoretically studied, considering also the antioxidant stability in the food simulants studied at different temperatures.On the other hand, a phenomenological model based on a resistances-in-series which was resolved through the Regula Falsi algorithm according to a routine that considers the income of the structural parameters of the system and experimental conditions in which migration testing was performed. Diffusion coefficients of I-1076 in LDPE were ranged between 8.0E10–14 and 1.2E10–12 (m² s^{− 1}) for temperatures of 28 to 60 °C, respectively. The coupled effect of mass transfer and thermodynamical aspects was analyzed through the parameter Bi/K_P/FS proposed in this work, estimated in order to identify the combined contribution of the transport rate and the availability of the migrant compound in the food phase.     

Migration of di(2-ethylhexyl) maleate from cardboard boxes into foods

Di(2-ethylhexyl) maleate (DEHM) is a non-evaluated substance newly detected in the majority of the printed cardboard boxes used for food packaging. Concentrations in the board are often sufficient for a migration into food of around 1 mg/kg. This level was reached after storage over several months and in the absence of a functional barrier (such as a layer of aluminum). The maximum concentration determined in food was 1,500 μg/kg, even though the end of the shelf life of the product was not reached. DEHM is probably the non-reacted starting material in di(2-ethylhexyl) sulfosuccinate, which is used at concentrations of several percent as an emulsifier for water-based varnishes. A minor contribution is from recycled fibers, presumably contaminated through the same route. DEHM was absent in printing inks and almost all adhesives tested. No toxicological facts are available for DEHM. Through comparison with similar substances, the German BfR Committee for Consumer Products recommended a temporary migration limit of 50 μg/kg, whereas the Swiss Federal Office of Public Health concluded on a lower toxicity. The case shows that impurities in components used for printing cardboard may migrate at concentrations demanding substantial compliance work.     

Phthalate and adipate esters in Australian packaging materials

A total of 136 food packaging materials were analysed for the presence of six phthalate esters and one adipate ester. All of the sample materials were manufactured from either synthetic polymers or from wood pulp and most were in immediate contact with their food contents. The esters in the packaging materials were extracted into a 2:1 mixture of chloroform and methanol, and analysed by gas chromatography-mass spectrometry. All of the materials examined were found to contain two or more of these compounds above a detection limit of 0.01 μg/kg. Total phthalate concentrations ranged from 5 to 8160 μg/g and adipate concentrations ranged from not detected to 1728 μg/g. In general, materials with the most surface coverage of printing inks had the greatest concentrations of phthalates. Variations were noticed in the occurrence and concentrations of phthalate and adipate esters in the packaging materials over a 12 month period during 1996 and 1997.     

Determination of toluene and other residual solvents in various food packaging materials by gas chromatography/mass spectrometry (GC/MS)

Levels of toluene and other residual solvents were evaluated in food packaging materials as a preventive action against hazard occurrence in foods via migration and to confirm food safety. Automated headspace sampling and gas chromatography/mass spectrometry (HS-GC/MS) were used to determine residual solvent levels in the food packaging materials. Correlation coefficients as calibration factors were over 0.999 and relative standard deviations (RSD) of repeatability were below 3.6%. Limits of quantification (LOQ) ranged from 0.001 to 0.01 mg/m². The levels of 7 residual solvents including toluene for potential migration from food packaging materials to food samples were below Korean regulatory limits.     

Validation and application of an LC-MS/MS method for the determination of cyclic oligomers originating from polyamide 6 and polyamide 66 in food simulant

Polyamides (PAs) are used in the production of various food contact materials (FCMs) and articles such as kitchen utensils and packaging material. Cyclic oligomers have been identified as potential migrants from PA. This study describes the development, validation and application of a multi-oligomer analytical method based on LC-ESI-MS/MS for the identification and quantification of eight cyclic oligomers of PA 6 and four PA 66 migrating from FCMs into food simulant B (3% acetic acid) and beverages. It was proved that doubly charged precursor ions of the cyclic PA 6 and PA 66 oligomers above a mass of 500 Da are formed during the ionisation process of the electrospray technique used. Direct injection of a diluted food simulant into the LC-ESI-MS/MS system after migration makes the validated method a valuable tool for investigating migration of cyclic PA oligomers. The validation results demonstrate that the multi-oligomer method is applicable for the analysis of cyclic PA 6 and PA 66 oligomers in food simulant B. For all investigated cyclic PA oligomers, detection limits were in the range of 0.1–1.1 µg/l. Linearity (r² ≥ 0.99), trueness values between 91% and 122%, and intra-day (RSD_r < 10%) and inter-day precision (RSD_R < 19%) were determined and satisfied validation criteria set out by the European Reference Laboratory for FCMs. The method was extended to tap water and tea. Finally, the multi-oligomer method was successfully applied to determine cyclic PA oligomers in migration solutions originating from different PA FCMs. In all migration solutions, concentrations of cyclic PA oligomers were determined above the LOQ. A preliminary risk assessment based on in silico tools was performed. The results demonstrate the urgent need for toxicological data that would facilitate the evaluation of the health risk of cyclic PA oligomers.     

Potential for short-term migration of mineral oil hydrocarbons from coated and uncoated food contact paper and board into a fatty food simulant

ABSTRACT

Mineral oil hydrocarbons (MOH) are widely used in the food industry for applications such as printing inks, additives, adhesives, and processing aids for food additives. Recently, the migration of MOH from food contact paper and board into foods has raised public health concerns. In this study, a total of 110 food contact paper and board samples, including baking and cooking paper (23), baking cups (28), food packaging bags (22), lunch boxes (8), party plates (26), and straws (3) were evaluated to quantify the content and short-term migration levels of MOH. The MOH were separated into mineral oil saturated hydrocarbons (MOSH)/polyolefin oligomeric saturated hydrocarbons (POSH) and mineral oil aromatic hydrocarbons (MOAH) via a validated on-line liquid chromatography?gas chromatography?flame ionisation detection (LC–GC–FID) technique. The coating materials of the sample products comprised polyethylene, polypropylene, polyethylene terephthalate, and silicone. The effects of the coating materials on the content and migration of MOH/POSH were evaluated. Quantitative analysis of the MOH in the samples showed that the MOSH/POSH and MOAH content varied widely, ranging from 16 to 5626 mg kg^?1 for MOH, regardless of the coating materials. Short-term migration of MOSH/POSH was observed only in samples with polyolefinic coatings, such as polyethylene and polypropylene, in experiments conducted at 25 °C for 10 min, although the extent of MOAH migration for all samples was at the trace level. The migration of MOSH/POSH was detected within the range of 0.93 to 62.3 μg L^?1 in 22 samples, and the migration of MOAH was detected within the range of 0.80 to 2.6 μg L^?1 in only 4 samples. These results demonstrate that although the short-term migration potential of MOH is generally negligible, the migration of MOSH/POSH into wet fatty foods can be accelerated by polyolefinic coatings, even within a very short time.     

Multiple Mass Transfers of Small Volatile Molecules Through Flexible Food Packaging

This article deals with evolution of packed foodstuff quality with time of storage. The transport of small volatile molecules (flavor compounds, water vapor, and gases) into and through flexible food packaging materials is reviewed, as well as their multiple transfers. Sorption, diffusion, and permeation phenomena are distinguished. Transport properties are largely determined by packaging characteristics, flavor molecules properties, food matrix composition, and environmental conditions. Transfer of small volatile molecules into and through food packaging materials can modify food quality and properties of the packaging materials, thus possibly altering packed foodstuff shelflife. More research is required on transport of flavor molecules through packaging materials by considering liquid and solid food matrices flavored with mixtures of aroma compounds at more realistic concentrations; interactions of aroma compounds with food matrices, and with packaging being followed during storage in given environmental conditions.     

Multiple Mass Transfers of Small Volatile Molecules Through Flexible Food Packaging

This article deals with evolution of packed foodstuff quality with time of storage. The transport of small volatile molecules (flavor compounds, water vapor, and gases) into and through flexible food packaging materials is reviewed, as well as their multiple transfers. Sorption, diffusion, and permeation phenomena are distinguished. Transport properties are largely determined by packaging characteristics, flavor molecules properties, food matrix composition, and environmental conditions. Transfer of small volatile molecules into and through food packaging materials can modify food quality and properties of the packaging materials, thus possibly altering packed foodstuff shelflife. More research is required on transport of flavor molecules through packaging materials by considering liquid and solid food matrices flavored with mixtures of aroma compounds at more realistic concentrations; interactions of aroma compounds with food matrices, and with packaging being followed during storage in given environmental conditions.     

Migration of Chemical Compounds from Packaging Polymers during Microwave,Conventional Heat Treatment,and Storage

Polymeric packaging protects food during storage and transportation, and withstands mechanical and thermal stresses from high‐temperature conventional retort or microwave‐assisted food processing treatments. Chemical compounds that are incorporated within polymeric packaging materials to improve functionality, may interact with food components during processing or storage and migrate into the food. Once these compounds reach a specified limit, food quality and safety may be jeopardized. Possible chemical migrants include plasticizers, antioxidants, thermal stabilizers, slip compounds, and monomers. Chemical migration from food packaging is affected by a number of parameters including the nature and complexity of food, the contact time and temperature of the system, the type of packaging contact layer, and the properties of the migrants. Researchers study the migration of food‐packaging compounds by exposing food or food‐simulating liquids to conventional and microwave heating and storage conditions, primarily through chromatographic or spectroscopic methods; from these data, they develop kinetic and risk assessment models. This review provides a comprehensive overview of the migration of chemical compounds into food or food simulants exposed to various heat treatments and storage conditions, as well as a discussion of regulatory issues.     

Migration of nanoparticles from plastic packaging materials containing carbon black into foodstuffs

Carbon black was investigated to assess and quantify the possibility that nanoparticles might migrate out of plastic materials used in the food packaging industry. Two types of carbon black were incorporated in low-density polyethylene (LDPE) and polystyrene (PS) at 2.5% and 5.0% loading (w/w), and then subjected to migration studies. The samples were exposed to different food simulants according to European Union Plastics Regulation 10/2011, simulating long-term storage with aqueous and fatty foodstuffs. Asymmetric flow field-flow fractionation (AF4) coupled to a multi-angle laser light-scattering (MALLS) detector was used to separate, characterise and quantify the potential release of nanoparticles. The AF4 method was successful in differentiating carbon black from other matrix components, such as extracted polymer chains, in the migration solution. At a detection limit of 12 µg kg^?1, carbon black did not migrate from the packaging material into food simulants. The experimental findings are in agreement with theoretical considerations based on migration modelling. From both the experimental findings and theoretical considerations, it can be concluded that carbon black does not migrate into food once it is incorporated into a plastics food contact material.     

包装材料阻隔性对德州扒鸡的品质影响分析

为研究包装材料阻隔性对扒鸡贮藏期间品质的影响,采用三种不同阻隔性包装材料对德州扒鸡进行真空包装,并对扒鸡色差、TBA值、挥发性成分等理化指标进行检测分析,同时进行感官评定。结果表明:普通材料包装组扒鸡在贮藏过程中L*值、a*值快速下降,在第5 d即出现明显褐变(L*值由50.02降为46.34,a*值由16.33降为13.17),而两种高阻隔包装扒鸡贮藏过程中的L*值、a*值与初始值(L*值:50.02;a*值:16.33)均无显著差异(P0.05);两高阻隔包装组保存20 d后,TBA值分别为0.60 mg/kg和0.65 mg/kg,显著低于普通包装组(0.76 mg/kg)(P0.05);电子鼻和GC-MS分析结果表明高阻隔包装组保留了更多的含硫挥发性成分和香辛料挥发性成分;随着贮藏时间的延长,普通包装组出现哈喇味,而高阻隔包装组未出现。结论:高阻隔真空包装可有效保持扒鸡原有色泽,延缓脂肪氧化,并可较好地保持扒鸡的原有风味。