Simulation of migration from internal can coatings

Migration from can-coatings into retorted canned food simulants (canned oil and water, 121 degrees C, 30 min) was investigated through HPLC with a fluorescence detector and evaporative light scattering detector, and by measurements of residue on evaporation and consumption of potassium permanganate. HPLC analysis revealed that migration into the canned oil was hundreds of times more than that into n-heptane (25 degrees C, 60 min, the official test conditions according to the Japanese Food Sanitation Law), whereas it was similar to the migration into isooctane-butyl acetate mixtures (60 degrees C, 60 min), and that migration into the canned water was several times more than that into water (95 degrees C, 30 min, the official test conditions). Residue on evaporation for the n-heptane extract was several-fold lower than 30 ppm (the official limit), whereas that for the isooctane-butyl acetate mixtures exceeded 30 ppm. Consumption of potassium permanganate for the canned water was 30 times higher than that for the water extract (95 degrees C, 30 min). The official test conditions for can-coatings, in particular the use of n-heptane as an oil simulant, were suggested to lead to substantial underestimation of migration into canned food.     

Migration testing of plastics and microwave-active materials for high-temperature food-use applications

Temperatures have been measured using a fluoro-optic probe at the food/container or food/packaging interfaces as appropriate, for a range of foods heated in either a microwave or a conventional oven. Reheating ready-prepared foods packaged in plastics pouches, trays or dishes in the microwave oven, according to the manufacturers' instructions, resulted in temperatures in the range 61-121 degrees C. Microwave-active materials (susceptors) in contact with ready-prepared foods frequently reached local spot temperatures above 200 degrees C. For foods cooked in a microwave oven according to published recipes, temperatures from 91 degrees C to 200 degrees C were recorded, whilst similar temperatures (92-194 degrees C) were attained in a conventional oven, but over longer periods of time. These measurements form the basis for examining compliance with specific and overall migration limits for plastics materials. The testing conditions proposed depend on the intended use of the plastic - for microwave oven use for aqueous foods, for all lidding materials, and for reheating of foods, testing would only be required with aqueous simulants for 1 h at 100 degrees C; for unspecified microwave oven use, testing with olive oil would be required for 30 min at 150 degrees C; and for unspecified use in a conventional oven testing with olive oil would be required for 2 h at 175 degrees C. For microwave-active materials, it is proposed that testing is carried out in the microwave oven using a novel semi-solid simulant comprising olive oil and water absorbed onto an inert support of diatomaceous earth. The testing in this instance is carried out with the simulant instead of food in a package and heating in the microwave oven at 600 W for 4 min for every 100 g of simulant employed. There is an option in every case to test for migration using real foods rather than simulants if it can be demonstrated that results using simulants are unrepresentative of those for foods. The proposed testing conditions were validated as being realistic by measurement of the specific migration of various components from different plastics into foods under actual conditions of use and comparing with migration into simulants. Migration of plasticizers from PVC and VC/VDC copolymer films was monitored for both microwave reheating and cooking of foods. Total oligomer concentrations were measured from poly(ethylene terephthalate) (PET) trays, and volatile aromatics from thermoset polyester trays, using both types of container in microwave and conventional ovens.(ABSTRACT TRUNCATED AT 400 WORDS)     

聚碳酸酯食品容器卫生标准的探讨

目的为修订聚碳酸酯食品容器卫生标准,设定检测项目及其迁移限量提供科学依据。方法对聚碳酸酯食品容器的生产、食品接触情况进行现场调查,随机抽取60批次样品,检测蒸发残渣(水、4%乙酸、20%乙醇、正己烷)、高锰酸钾消耗量、游离酚和重金属,并同时检测双酚A特定迁移量。结果检测结果显示,蒸发残渣、游离酚和重金属的合格率均为100%,高锰酸钾消耗量的合格率为98.2%,双酚A特定迁移量检出值范围为0.5～3.0μg/kg,检出均值为0.9±0.4μg/kg。结论根据检测结果、风险评估资料,参考美国FDA、日本、欧盟法规,提出了我国聚碳酸酯食品容器卫生标准的修订意见。     

Comparison of the migration of melamine from melamine-formaldehyde plastics ('melaware') into various food simulants and foods themselves

A variety of melaware articles were tested for the migration of melamine into the food simulant 3% w/v acetic acid as a benchmark, and into other food simulants, beverages and foods for comparison. The results indicate that the acidity of the food simulant plays a role in promoting migration, but not by as much as might have been anticipated, since 3% acetic acid gave migration values about double those obtained using water under the same time and temperature test conditions. In contrast, migration into the fatty food simulant olive oil was not detectable and at least 20-fold lower than with the aqueous food simulants. This was expected given the solubility properties of melamine and the characteristics of the melaware plastic. Migration levels into hot acidic beverages (apple juice, tomato juice, red-fruit tea and black coffee) were rather similar to the acetic acid simulant when the same time and temperature test conditions are used, e.g. 2 h at 70°C. However, migration levels into foods that were placed hot into melaware articles and then allowed to cool on standing were much lower (6-14 times lower) than if pre-heated food was placed into the articles and then maintained (artificially) at that high temperature in the same way that a controlled time-temperature test using simulants would be conducted. This very strong influence of time and especially temperature was manifest in the effects seen of microwave heating of food or beverage in the melaware articles. Here, despite the short duration of hot contact, migration levels were similar to simulants used for longer periods, e.g. 70°C for 2 h. This is rationalized in terms of the peak temperature achieved on microwave heating, which may exceed 70°C, counterbalancing the shorter time period held hot. There was also evidence that when using melaware utensils in boiling liquids, as for stovetop use of spatulas, the boiling action of circulating food/simulant can have an additional effect in promoting surface erosion, increasing the plastic decomposition and so elevating the melamine release.     

Comparison of the migration of melamine from melamine–formaldehyde plastics (‘melaware’) into various food simulants and foods themselves

A variety of melaware articles were tested for the migration of melamine into the food simulant 3% w/v acetic acid as a benchmark, and into other food simulants, beverages and foods for comparison. The results indicate that the acidity of the food simulant plays a role in promoting migration, but not by as much as might have been anticipated, since 3% acetic acid gave migration values about double those obtained using water under the same time and temperature test conditions. In contrast, migration into the fatty food simulant olive oil was not detectable and at least 20-fold lower than with the aqueous food simulants. This was expected given the solubility properties of melamine and the characteristics of the melaware plastic. Migration levels into hot acidic beverages (apple juice, tomato juice, red-fruit tea and black coffee) were rather similar to the acetic acid simulant when the same time and temperature test conditions are used, e.g. 2?h at 70°C. However, migration levels into foods that were placed hot into melaware articles and then allowed to cool on standing were much lower (6–14 times lower) than if pre-heated food was placed into the articles and then maintained (artificially) at that high temperature in the same way that a controlled time–temperature test using simulants would be conducted. This very strong influence of time and especially temperature was manifest in the effects seen of microwave heating of food or beverage in the melaware articles. Here, despite the short duration of hot contact, migration levels were similar to simulants used for longer periods, e.g. 70°C for 2?h. This is rationalized in terms of the peak temperature achieved on microwave heating, which may exceed 70°C, counterbalancing the shorter time period held hot. There was also evidence that when using melaware utensils in boiling liquids, as for stovetop use of spatulas, the boiling action of circulating food/simulant can have an additional effect in promoting surface erosion, increasing the plastic decomposition and so elevating the melamine release.     

High-temperature migration of antioxidants from polyolefins

Migration rates of radiolabelled antioxidants, Irganox-1010 (I-1010) and Irganox-1076 (I-1076), were measured from low- and high-density polyethylenes (LDPE, HDPE) and polypropylene (PP) at temperatures up to 135 degrees C. Water, 8 and 95 per cent aqueous ethanol and corn oil were employed as food simulating liquids (FSL). The experiments were conducted in a high-pressure cell in a manner that allowed contact between the polyolefin plaque and the FSL only during the test period and not while being heated. The migrations of the antioxidants varied with the square root of time, and the Fickian diffusion coefficients could be correlated with temperature in an Arrhenius fashion. Under comparable test conditions, antioxidant migrations were largest from PP for aqueous simulants, but for non-aqueous simulants the highest losses were from LDPE. In both instances lowest losses were from HDPE. In most instances there was little difference between the migration behaviour of I-1010 and I-1076. A few tests were conducted to measure the antioxidant migrations to foods. The losses were usually larger than those to water but below those to corn oil.     

Migration of a UV stabilizer from polyethylene terephthalate (PET) into food simulants

The migration characteristics of the UV stabilizer Tinuvin 234 (2-(2H-benzotriazol-2-yl)-4,6-bis (1-methyl-1-phenylethyl)phenol) into food simulants has been measured from polyethylene terephthalate (PET) using HPLC with UV detection. Ethanol/water, isooctane and a fractionated coconut oil simulant (Miglyol®) were used as food simulating solvents. The migration characteristics were measured at temperatures in the range of 40-70°C. Diffusion coefficients were determined to be in the range of 1 × 10^-14 cm² s^-1 to 1 × 10^-18 cm² s^-1. At 40°C, the amount of migration into 95% ethanol after 10 days was 2 μg dm^-2. Isooctane is determined to be a good fatty food simulant that provides similar results for PET to those of fatty foods.     

Migration of 4-nonylphenol from polyvinyl chloride food packaging films into food simulants and foods.

Migration of 4-nonylphenol (NP) from polyvinyl chloride (PVC) films for food packaging into food simulants and foods has been studied in domestic applications such as wrapping of food and reheating in a microwave oven. The migration of NP from the PVC films was determined by high-performance liquid chromatography with electrochemical coulometric-array detection (LC/ED). Twelve PVC films intended for commercial use and ten for domestic applications (total: 22 samples) were analysed. Some of the PVC films (two home-use and ten retail-use) contained NP at concentrations of between 500 and 3300 microg/g. Migration of NP from the films was influenced by the test conditions (n-heptane at 25 degrees C for 60 min, distilled water at 60 degrees C for 30 min and 4% acetic acid at 60 degrees C for 30 min). The amount of NP migrating from the PVC films into n-heptane (0.33-1.6 microg/cm2) was higher than the amount migrating into distilled water or 4% acetic acid (up to 9.7 ng/cm2) for the 11 films in which NP was detected. Up to 0.23% of the NP migrated into distilled water and 4% acetic acid and up to 62.5% into n-heptane. In addition, we investigated NP migration into cooked rice samples wrapped in PVC film. Using spiked samples the method gave an average recovery of 83.7% (n = 5) with a standard deviation of 2.5%. Migration of NP ranged from not detectable (< 1.0 ng/g) to 410.0 ng/g by reheating samples in a microwave oven for 1 min and from not detectable to 76.5 ng/g by keeping samples at room temperature for 30 min.     

Migration of melamine from can coatings cross-linked with melamine-based resins,into food simulants and foods

Resins based on melamine-formaldehyde and related analogues such as methylolated melamine are used to cross-link coatings used inside food cans and on the metal closures of glass jars. Thirteen commercially coated cans and closures representing 80% of the European market were tested using simulants under realistic industrial heat-processing conditions for canned and jarred foods. The food simulants and the retort conditions used were 3% acetic acid for 1?h at 100°C and 10% ethanol for 1?h at 130°C. The highest migration level seen for melamine into simulant was 332?µg?kg^?1. There was no detectable migration of the melamine analogues cyanuric acid (<1?µg?kg^?1) or ammelide (<5?µg?kg^?1) from any sample. Twelve of the thirteen samples released no detectable ammeline (<5?µg?kg^?1) but the coating giving the highest release of melamine did also release ammeline at 8?µg?kg^?1 with the higher of the two process temperatures used. Migration experiments into food simulant and foods themselves were then conducted using two experimental coatings made using amino-based cross-linking resins. Coated metal panels were exposed to the food simulant 10% (v/v) aqueous ethanol and to three foodstuffs under a range of time and temperature conditions both in the laboratory and in a commercial food canning facility using proprietary time and temperature conditions. The highest migration into a food was 152?µg?kg^?1 from the first coating processed for a long time at a moderate sterilisation temperature. The highest migration into simulant was also from this coating at 220?µg?kg^?1 when processed at 134°C for 60?min, dropping to 190?µg?kg^?1 when processed at 123°C for 70?min. Migration from the second coating was quite uniformly two to three times lower under all tests. These migration results were significantly higher than the levels of melamine extractable using 95% ethanol at room temperature. The experiments show that commercial canning and retorting can be mimicked in an acceptable way using laboratory tests with an autoclave or a simple pressure cooker. The results overall show there is hydrolytic degradation of the melamine cross-linked resins to release additional melamine. There is a strong influence of the temperature of heat treatment applied with foods or simulants but only a minor influence of time of heating and only a minor influence, if any, of food/simulant acidity.     

Effects of Oxygen and Water Vapor Transmission Rates of Polymeric Pouches on Oxidative Changes of Microwave-Sterilized Mashed Potato

Polymer-based packaging with low oxygen (OTR) and water vapor transmission rates (WVTR) can be used to limit oxidative chemical changes in packaged foods, especially for the 3- to 5-year shelf life required for military rations and long-duration space foods. Microwave-assisted thermal sterilization (MATS) produces higher quality food with a potentially longer shelf life as a result of volumetric heating and the associated shorter process time. This study investigated the effects of the package-MATS process interactions and the resultant package barrier properties on food quality, using a mashed potato model food following MATS process of F₀?=?9 min for 12 weeks at 50 °C. Two poly ethylene terephthalate (PET)-based (MFA, MFC) and one ethylene vinyl alcohol (EVOH)-based (MFB) retort pouches were tested, with OTRs of 0.20, 2.11, and 0.07 cc/m²·day and WVTRs of 2.64, 1.78, and 0.29 g/m²·day for MFA, MFB, and MFC, respectively; a foil double-sealed MFA pouch served as a control (MF0).Barrier properties did not influence oxygen content in polymer pouches during storage (p?>?0.05). From the third week to the fifth week of storage, significant differences (p?<?0.05) were observed in total color difference (ΔE) and oxidation indicators (TBARS, hexanal, and nonanal). The mashed potato treated in higher barrier property pouches exhibited less color change and oxidation than those in lower barrier property pouches. The performance of the MFC pouch was similar overall to that of the metal pouch. These findings suggested that high-barrier packages are suitable for MATS or other commercially sterile foods, particularly for long shelf-life purpose.     

Temperature and pH affect copper release kinetics from copper metal foil and commercial copperware to food simulants

ABSTRACT

Copper (Cu) metal and alloys are used in cookware and other food contact surfaces due to their desirable properties for various applications. However, Cu metal can ionise and subsequently transfer to food and beverages under certain conditions. Here, we tested how pH and temperature affected Cu release kinetics using model systems utilising Cu metal foil and commercially available copperware. Cu foil and copperware were exposed to food simulants composed of 3% (w:w) aqueous solutions of citric acid, malic acid, acetic acid, or deionised (DI) water at temperatures ranging from 4°C to 60°C. An additional pilot experiment tested how simulated long-term cleaning affected subsequent Cu release from lined and unlined copperware to 3% citric acid. Food simulants were then analysed by ICP-MS for total Cu. After 180 min, incubation of Cu metal foil with acid-containing food simulants at 4°C resulted in Cu release ranging from 8.7 - 14.0 µg cm^?2, while 21.5–38.1 µg cm^?2 was released at 60°C. In contrast, Cu transfer from metal foil to DI water was relatively low, with <0.6 µg cm^?2 released after 180 min at 60°C. With citric acid food simulant, lined copperware released between 0.6 and 3.0 µg Cu cm^?2 over 180 min at the set temperatures, while unlined copperware released approximately 25–45 fold higher amounts of Cu (26.9–74.6 µg cm^?2) over this same time period. In contrast, use of DI water food simulant resulted in Cu release of <0.1 µg cm^?2 for the lined copperware and <2 µg cm^?2 for the unlined type. No significant effect of simulated long-term cleaning on Cu release from copperware was observed. These data indicate that Cu release is affected by temperature and pH, and that specific steps can be taken to limit Cu metal release from food contact surfaces to foods and beverages.     

Hot water postprocess pasteurization of cook-in-bag turkey breast treated with and without potassium lactate and sodium diacetate and acidified sodium chlorite for control of Listeria monocytogenes

Surface pasteurization and food-grade chemicals were evaluated for the ability to control listeriae postprocess on cook-in-bag turkey breasts (CIBTB). Individual CIBTB were obtained directly from a commercial manufacturer and surface inoculated (20 ml) with a five-strain cocktail (ca. 7.0 log) of Listeria innocua. In each of two trials, the product was showered or submerged for up to 9 min with water heated to 190, 197, or 205 degrees F (ca. 87.8, 91.7, or 96.1 degrees C) in a commercial pasteurization tunnel. Surviving listeriae were recovered from CIBTB by rinsing and were then enumerated on modified Oxford agar plates following incubation at 37 degrees C for 48 h. As expected, higher water temperatures and longer residence times resulted in a greater reduction of L. innocua. A ca. 2.0-log reduction was achieved within 3 min at 205 and 197 degrees F and within 7 min at 190 degrees E In related experiments, the following treatments were evaluated for control of Listeria monocytogenes on CIBTB: (i) a potassium lactate-sodium diacetate solution (1.54% potassium lactate and 0.11% sodium diacetate) added to the formulation in the mixer and 150 ppm of acidified sodium chlorite applied to the surface with a pipette, or (ii) a potassium lactate-sodium diacetate solution only, or (iii) no potassium lactate-sodium diacetate solution and no acidified sodium chlorite. Each CIBTB was inoculated (20 ml) with ca. 5 log CFU of a five-strain mixture of L. monocytogenes and then vacuum sealed. In each of two trials, half of the CIBTB were exposed to 203 degrees F water for 3 min in a pasteurization tunnel, and the other half of the CIBTB were not; then, all CIBTB were stored at 4 degrees C for up to 60 days, and L. monocytogenes was enumerated by direct plating onto modified Oxford agar. Heating resulted in an initial reduction of ca. 2 log CFU of L. monocytogenes per CIBTB. For heated CIBTB, L. monocytogenes increased by ca. 2 log CFU per CIBTB in 28 (treatment 1), 28 (treatment 2), and 14 (treatment 3) days. Thereafter, pathogen levels reached ca. 7 log CFU per CIBTB in 45, 45, and 21 days for treatments 1, 2, and 3, respectively. In contrast, for nonheated CIBTB, L. monocytogenes levels increased from ca. 5 log CFU per CIBTB to ca. 7 log CFU per CIBTB in 28, 21, and 14 days for treatments 1, 2, and 3, respectively. Lastly, in each of three trials, we tested the effect of hot water (203 degrees F for 3 min) postprocess pasteurization of inoculated CIBTB on the lethality of L. monocytogenes and validated that it resulted in a 1.8-log reduction in pathogen levels. Collectively, these data establish that hot water postprocess pasteurization alone is effective in reducing L. monocytogenes on the surface of CIBTB. However, as used in this study, the potassium lactate-sodium diacetate solution and acidified sodium chlorite were only somewhat effective at controlling the subsequent outgrowth of this pathogen during refrigerated storage.     

Development and validation of an HPLC method with fluorescence detection for the determination of fluorescent whitening agents migrating from plastic beverage cups

An HPLC method with fluorescence detection has been developed and validated for the quantification of six fluorescent whitening agents (FWA) in plastic beverage cups after extraction and in food simulants after migration at 70°C for 2 h. The sensitivity of the method was high with LODs ranging from 0.053 to 0.251 μg kg^?1 and LOQs from 0.107 to 0.504 μg kg^?1. Accuracy and precision were highly acceptable, with recoveries greater than 82% and RSDs (%) below 16%. The expanded combined uncertainty was found to be less than 23% for the measurements of all studied FWAs. In extracting the analytes from food contact materials (FCM), accelerated solvent extraction (ASE) and Soxhlet extraction were applied using ethanol as the extraction solvent. The results obtained for FWA in 10 different food plastic cups, made from different polymers, were compared. The ASE technique proved to be faster, more effective and efficient than Soxhlet extraction. Migration tests with official food simulants from Regulation (EU) No 10/2011 showed that the substances studied could potentially migrate using the selected migration conditions. The most pronounced effect was observed in case of simulant D1 (50% w/v ethanol in water). The analytical method proved to be a simple, fast, sensitive and reliable tool for the simultaneous quantification of six of the most used FWAs in both FCM extracts and food simulants after migration experiments.     

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.     

Stability testing of selected plastics additives for food contact in EU aqueous, fatty and alternative simulants

Within the framework of the AIR3-CT94-2360 EUproject, the stability of three plastics additives in three EU aqueous and fatty food simulants and in two alternative simulants was studied under various timetemperature conditions. The additives tested were bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP) and octadecyl 3-(3,5-di- tert -butyl4-hydroxyphenyl) propionate (Irganox 1076). The various test conditions included exposures of 10 days at 40 o C, 1h at reflux temperature for all aqueous simulants, 10 days at 40 o C and 1h 175 o C for the olive oil and 2 days at 20 o C and 3h at 60 o C for the isooctane simulant. Following the exposure, the additive samples were extracted from aqueous simulants with hexane. A sonication step was necessary to ensure maximum extraction of control samples. In the case of the isooctane simulant, the samples were analysed directly from the simulant. The oil samples were extracted by acetonitrile. The extracts of samples exposed to various heat conditions as well as unexposed spiked controls and blanks were analysed by gas chromatography (GC) on a non-polar (5% -phenyl)-methylpolysiloxane capillary column with high temperature capabilities. The results showed that DEHA, DEHP and Irganox 1076 were stable at 40 o C and at reflux temperature in ethanolic or acidic aqueous simulants. The various additives were also stable in the organic isooctane simulant as well as in the fatty simulant olive oil. Studies on the stability of such additives used in food packaging are designed for regulatory purposes as an aid to decide whether the legislation should regulate limits for plasticizers based on a quantity in the food packaging itself or based on an ingested dose by the consumer.     

食品包装PE材料中荧光增白剂迁移规律的分析

以PE塑料薄膜为研究对象,采用高效液相色谱法研究食品包装塑料材料中荧光增白剂在纯水、乙酸、乙醇、植物油4?种不同模拟物中的迁移规律,研究荧光增白剂溶出量与食品接触介质、乙酸质量浓度、乙醇体积分数、浸泡温度以及处理时间等因素的关系。结果表明：纯水基质食品模拟物对香豆素类荧光增白剂有一定溶解性,酸性食品模拟物相比于水模拟物有更强的溶解性,而含醇类食品模拟物和脂肪类食品模拟物对大部分荧光增白剂都具有较好的溶解效果;荧光增白剂的溶出量随着乙酸和乙醇含量的增加而增加;较高的温度对塑料包装材料中荧光增白剂的迁移溶出具有显著影响,并且随着接触时间的延长,塑料包装材料中的荧光增白剂向食品中迁移的可能性也不断增大。     

Migration of trimellitic acid from epoxy anhydride can coatings into foods

The migration of trimellitic acid and its esters from epoxy anhydride coatings was determined in simulants as well as in canned foods. The most appropriate simulant was a combination of EC simulants B and C: 2% acetic acid/10% ethanol in water. The average migration into food was 900 μg kg^-1. This far exceeds the 50 μg kg^-1 for which the safety of trimellitic acid and its anhydride is ensured and the Swiss legal limit (QM(T) of 5 mg kg^-1 coating). Furthermore, much trimellitic acid migrated as (unidentified) esters, i.e. toxicological testing of free trimellitic acid is inadequate for the material that in reality migrates.     

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.     

筷子涂层中重金属元素的暴露研究

目的研究筷子涂层中12种重金属元素(锌、铜、镍、镉、铅、汞、铬、钼、硒、砷、钡、锑)在体液模拟物和食品模拟物中的暴露。方法以胃液模拟物、唾液模拟物作为体液模拟物,以4%乙酸(V/V)、水、95%乙醇(V/V)作为食品模拟物,利用电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)法测定筷子涂层中12种重金属元素的溶出量和迁移量。结果对20批次筷子涂层中12种重金属元素的含量进行测试发现10种重金属元素(锌、铜、镍、镉、铅、铬、钼、硒、砷、钡)有检出,其中铅元素含量高达347660.8mg/kg。对检出的重金属元素进一步分析其在体液模拟物中的溶出量和食品模拟物中的迁移量,发现高含量的元素能通过体液模拟物溶出和食品模拟物迁移。结论筷子涂层中重金属元素可能通过3种途径暴露至人体,分别是胃液溶出、唾液溶出、食品中迁移,且涂层涂覆的位置可对重金属元素的暴露途径产生影响;胃液模拟物中溶出量是唾液模拟物中溶出量的10倍以上;4%乙酸(V/V)食品模拟物中的迁移量最多可高于水和95%乙醇(V/V)食品模拟物中的迁移量近1000倍,且随着迁移次数的增加迁移量逐渐降低。     

Effect of High-Pressure Food Processing on the Physical Properties of Synthetic and Biopolymer Films

ABSTRACT:  The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 °C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.