Permeability of naphthalene in different types of polymeric food packaging materials

The relative permeabilities of naphthalene through different types of common polymeric food packaging materials were determined by migration studies in a controlled environment. The results illustrate that polyolefins, such as low density polyethylene (LDPE), have a higher relative permeability than other polymers, such as polyethylene terephthalate (PET) or polyvinylchloride co-polymer (PVC). This was explained by the correlation between the permeability of the migrant and the glass transition temperature (Tg) of the different polymers, as well as their polarity.     

Changes in polymer foils used in food packaging tested by using differential scanning calorimetry

This work is an experimental study of the differential scanning calorimetry characterisation of polymer materials used in food packaging materials, such as polypropylene (0.03 mm), polyethylene (0.1 and 0.03 mm), poly(D-(-)-Β-hydroxybutyrate) (powder), two-layered polypropylene (0.064 mm), and two-layered polypropylene with poly-vinylidene-chloride (0.012/0.021). The polymer stability was checked by simulation of conditions during food preparation in microwave ovens, sterilisation or rapid freezing. The materials were tested in the temperature range from 40 to 200‡C at different scan rates from 2 to 30°C min⁻¹ during heating or cooling. The enthalpies show a high correlation coefficient (0.964) with scan rate. All samples undergo phase change in the temperature range from 107 to 173°C during heating and enthalpies are in the range from 31.8 to 71.1Jg⁻¹. Upon subsequent cooling from 200°C, the temperature range of phase changes is shifted to lower temperatures from 86 to 102°C with enthalpies ranging from 30.4 to 57.8 J g⁻¹. Experiments with exposure of polymers to microwave radiation and freezing prove that the phase change considering the temperature range is very similar in all experiments.     

Potency evaluation of a dermaseptin S4 derivative for antimicrobial food packaging applications

Antimicrobial packaging is part of the broader area of active packaging, in which the package absorbs/releases different compounds during the product's storage and plays a major role in maintaining quality, extending shelf‐life and improving the product's safety. Antimicrobial packages are capable of inhibiting the detrimental effects of spoiling microorganisms in food products. There has been very great interest in antimicrobial packaging in recent years and many such packaging materials have been proposed, some of which containing synthetic additives and others natural additives. In the present study, antimicrobial materials containing the antimicrobial peptide (AMP) dermaseptin K₄K₂₀‐S4, which shows cytolytic activity in vitro against a broad spectrum of pathogenic microorganisms, such as bacteria, protozoa, yeast and filamentous fungi, were investigated. The study was aimed at evaluating the potency of this AMP as an antimicrobial agent for antimicrobial food packaging in two forms: (a) an aqueous solution of AMP was applied onto a polyethylene shrink‐wrapping film; (b) the AMP was incorporated in a corn starch‐based coating and applied directly onto the foodstuff (fresh cucumbers). Of these two versions, the latter has shown a greater efficiency against moulds and aerobic bacteria, even at lower surface concentrations of AMP (4.5µg/dm² vs. 3.5–3.8µg/dm²) in the coating. While in the first version the AMP had slowed down the growth of microorganisms only slightly, incorporation of AMP into the coating caused a reduction in their concentration practically to zero. Copyright © 2006 John Wiley & Sons, Ltd.     

Evaluation of measures to mitigate mineral oil migration from recycled paper in food packaging

The presence of mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH) in food is a safety concern. Migration to food from recycled paper and board is a relevant source of MOSH and MOAH, and the potential of several technologies to reduce it was explored. These technologies were assessed for food safety (people), environment (planet) and economy (profit) in an integrated way, using a framework developed to compare the effect of the technologies with the current state of the art. Two mature technologies were evaluated (MB12 and flotation), two in development (supercritical CO₂ and thermal treatment), and two as a concept (anionic trash catchers and functionalized clays). The use of mineral-oil-free inks for printing newspapers was also evaluated. It was concluded that, although it is desirable to apply mineral-oil-free inks, in the short-term reduction technologies have more impact. All technologies of which the effectiveness could be investigated (MB12, flotation, supercritical CO₂ and thermal treatment) are able to reduce the potential migration of mineral oils by >70%, but none score optimally on all indicators. The MB12 technology shows the best overall performance and is ready for implementation, provided its patent will be available to more parties. Supercritical CO₂ performs best on food safety, but environmental and economic performance has to be improved. The developed assessment framework yields a clear overview of the advantages and disadvantages of the technologies. Based on the assessment, recommendations are made to stakeholders, including the recycling industry, the ink and printing industry, the food industry and research institutes.     

The influence the image of the product shown on food packaging labels has on product perception during tasting: Effects and gender differences

Many food packages on the market show an image of the product contained inside or the ingredients with which the product was produced. During the packaging design process, it is the job of the designer or the marketing team to decide which specific image will be depicted on the packaging. This paper analyses the potential implications of this decision by studying the influence that the visual appearance of the product pictured on the packaging has on the way consumers perceive the product during consumption. Two packaging designs for apple sauce were created; the only variable was the visual appearance of the apple displayed: one showed a red apple and the other showed a green one. The 147 participants in this between‐subjects experiment tasted and evaluated six product attributes (Sweet, Acidic, Intense Flavour, Healthy, Natural, and Quality) as well as Liking and Willingness to buy. The results of a MANOVA‐Biplot analysis show that the visual appearance of the product pictured affects Liking, Willingness to buy, and some product attributes. In fact, a strong positive relationship was identified between the attribute Healthy and the perceived quality of the product with Liking and Willingness to buy; if one of these attributes scored higher, the higher score was extrapolated to the others. The study also shows that gender differences exist as these effects do not affect all consumers equally, with women being more sensitive to them than men. This paper discusses the implications of these results for the food industry, for packaging designers and for marketers.     

紫外光分光光度法测定食品包装纸用天然色素虎杖黄酮含量的研究

研究了紫外光分光光度法测定食品包装纸用色素虎杖黄酮含量的方法,以芦丁为参照品,测量波长为359nm,平均回收率为99.96%,精密度为1.34%,说明紫外分光光度法是一种较理想的测定方法.     

包装废聚丙烯复合改性沥青防水材料研究

利用回收的包装废弃聚丙烯、废胶粉代替普通聚合物改性剂，采用复合改性的技术方法，对普通沥青进行改性，提高基质沥青的防水性能。结果表明，改性后沥青的软化点、5℃延度提高，针入度降低，不透水性得到明显提高；不同混合比改性效果显示复合改性沥青综合性能优于单一改性剂直接改性。通过FT-IRF、微观结构分析，对复合改性沥青的高、低温性能，抗变形能力进行了研究，表明改性剂的溶胀及其与沥青形成的空间网络结构、银纹支化、应力剪切作用是产生改性效果的重要原因。     

Inhibition of microbial growth in ready‐to‐eat food stored at ambient temperature by modified atmosphere packaging

This study was undertaken to develop a modified atmosphere package to control microbial growth in ready‐to‐eat (RTE) products stored at ambient temperature. Ethanol and/or limonene associated with modified atmosphere (CO₂ : O₂ : N₂ = 30% : 5% : 65%) was used to inhibit the growth of total air‐borne microorganisms and Escherichia coli in RTE products stored at 25°C. The results indicated that 0.05% ethanol vapour in the headspace was effective to inhibit the growth of air‐borne microorganisms and E. coli at 25°C for 72 h in a model study, and the effectiveness was related to ethanol content. Both 73 ppm limonene and 0.05% ethanol vapour enhanced the bacteriostatic effect of modified atmosphere in RTE sushi roll products, and no off‐flavour was detected using this formulated gas; however, no significant inhibitory effect was observed for RTE cold noodle products. This study concludes that combinations of carbon dioxide, ethanol or limonene vapours are effective to inhibit microbial growth in RTE food at ambient temperature, and the outcome may be due to the hurdle effect. Copyright © 2003 John Wiley & Sons, Ltd.     

The effects of γ‐irradiation on compositional changes in plastic packaging films

Sterilization of packaging materials for pharmaceutical or food products with ionizing irradiation can cause chemical and physical changes in polymer materials. The effects of γ‐irradiation on the formation of solvent extractable radiolysis products of six flexible packaging materials for foodstuffs and/or pharmaceutical applications were studied after treatment in a ⁶⁰Co‐irradiation plant. The polymer materials polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polystyrene and poly(vinyl chloride) were investigated after treating with an irradiation dose of 44 kGy. The compositional changes in solvent extractable radiolysis products of each packaging material were quantified. In most cases the radiolysis products formed could be identified using GC/MS. The polyolefine materials (PE and PP) showed an increase of low volatile compounds after irradiation due to an oxidative decomposition of the polymer and typical polymer substances like oligomers and additives. Other packaging materials such as PET, PA and PS did not significantly change their amount of solvent extractable compounds after irradiation with 44 kGy. The PVC packaging material used in this study was not resistant to irradiation treatment at all. Because of the release of HCl during irradiation a large amount of volatile substances could be extracted from the PVC sheet. For consumer protection and also to meet general food packaging legislative requirements for irradiated packaging materials, it is necessary to evaluate the compositional changes in the polymers during irradiation, especially for irradiated polyolefines and PVC. Most attention should be paid to low volatile radiolysis products which are the most likely to migrate into a foodstuff or a pharmaceutical product. Copyright © 1999 John Wiley & Sons, Ltd.     

Detection and Identification of Oestrogen‐Active Substances in Plastic Food Packaging Migrates

Migrates from plastic food packaging were tested for oestrogen activity by yeast oestrogen screen and subsequently analysed by gas chromatography—mass spectrometry and high‐performance liquid chromatography—mass spectrometry to identify oestrogen‐active chemicals. Plastic samples were migrated according to EC 10/2011 with worst case scenarios being used. Food simulants consisted of either 10–95% ethanol or ultrapure water. Migrates were concentrated afterwards by solid phase extraction. Food contact material tested included polyethylene terephthalate, polypropylene, polyethylene, polystyrene and composite films. Oestrogenic activity ranging from 0.7 to 59 ng/l 17ß‐estradiol equivalents was detected in seven out of 42 samples tested. The highest activity was found in a composite film sample. All 11 polyethylene terephthalate samples tested negative for oestrogen activity. A number of chemicals with known or supposed oestrogen activity were identified in migrates of oestrogen‐active samples. These include butylated hydroxytoluene, 1,3‐diphenylpropane, 1,2‐diphenylcyclobutane and dibutyl phthalate. Copyright © 2013 John Wiley & Sons, Ltd.     

Investigating the diffusional behaviour of Irganox®1076 antioxidant in HDPE/Cloisite®15A nanocomposite‐based food contact packaging films: Effect of nanoclay loading

In this research work, the prediction of the diffusion coefficient (D_p) of Irganox ® 1076 (Ir‐76) antioxidant in HDPE‐based food contact packaging films was carried out. The diffusion of this additive was studied both, in neat HDPE film and in HDPE nanocomposites films made of HDPE matrix filled with 1, 3, and 5 wt% of a commercially available organoclay (Cloisite ® 15A). The diffusion experiments were carried out by using the Roe's method on films consisting of a stack of several polymer films having a total nominal thickness of 120 ± 01 μm. Diffusion coefficients were determined in the temperature range 80°C to 100°C according to the second Fick's law by measuring the evolution of the Ir‐76 concentration in the films by means of Fourier transform infrared (FTIR) spectroscopy analysis. The results indicated that the diffusion coefficient of Ir‐76 in HDPE films decreased with the addition of the organoclay, and a maximum reduction of 78% (at 23°C) in the diffusion rate of the Ir‐76 was observed at an optimum filler content of 3 wt%, thus making these films attractive for the plastic packaging industry.     

Determination of Four Types of Hazardous Chemicals in Food Contact Materials by UHPLC‐MS/MS

A simple ultrahigh‐performance liquid chromatography (UHPLC) tandem mass spectrometric method for the identification and quantification of two photoinitiators 4‐methylbenzophenone and 2‐ethylhexyl‐4‐dimethylaminobenzoate; nine plasticizers including di(2‐ethylhexyl) adipate and diisobutyl adipate; three primary aromatic amines 4‐aminobiphenyl, 4‐amino‐2′,3‐dimethylazobenzene and bis‐(4‐aminophenyl) methane and six bisphenols bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, bisphenol A (BPA), bisphenol B (BPB), bisphenol E (BPE) and bisphenol F (BPF) in food contact materials has been developed. The chromatographic conditions, pre‐treatment methods and matrix effects were studied and optimized. For the determination of the four bisphenols, BPA, BPB, BPE and BPF, the UHPLC method employed a mobile phase of aqueous ammonia and methanol in binary gradient mode, and measurement was based on a triple quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source operating in negative ion mode. The remaining chemicals were determined using the ESI source in positive ion mode and using the [M + NH₄]⁺ or [M + H]⁺ adducts as precursor ions for tandem mass spectrometry. The calibration graphs were linear with correlation coefficients of above 0.995. Detection limits for the method were in the range of 1–16 µg/kg. Analyte recovery values were in the range of 70–114%, and relative standard deviations were 1–14%. Under optimized conditions, the chromatographic separation was performed in 12 min. The validation data indicated that the method was effective for the determination of the four classes of hazardous chemicals in plastic packaging materials or in can lacquers. The optimized method was successfully applied to trace analysis of commercially available food contact materials. Copyright © 2014 John Wiley & Sons, Ltd.