Whey protein active films incorporated with a blend of essential oils: Characterization and effectiveness

Whey protein concentrate (WPC) films incorporated with a blend of Cinnamomum cassia, Cinnamomum zeylanicum, and Rosmarinus officinalis essential oils were characterized and evaluated for their effectiveness as an antioxidant for food applications. The effect of the incorporation of essential oils (EOs) at different concentrations (1, 2, 2.7, and 5% w/w) in WPC were studied by measuring their physical, optical, mechanical, and microstructural properties, in order to evaluate their behavior as a food packaging. The effectiveness of these active WPC films as a packaged was evaluated using a fatty food model (salami). The state of the salami oxidation was measured by the TBARs and hexanal assays during 180 days of storage. A yellowish characteristic color and opacity of WPC‐based films tend to increase with the increase of the EO concentration in the film formulation. While films containing 1 and 2% of EOs showed to be the most hydrophobic and present the lowest moisture content and solubility in water, films with higher EOs % (2, 2.7, and 5%, w/w) presented the highest water vapor transmission rate. The developed WPC active films showed to be heterogeneous, presenting cracks and pores due to the weakening of the polymer chain interaction forces by the EOs, which affected their mechanical behavior. WPC films incorporated with EOs may retard lipid oxidation induced by UV light in food. Besides, they showed to be very effective in the reduction of lipid oxidation in a previous assay with salami, with a longer storage time.     

Diffusional Behaviour of Essential Oil Components in Active Packaging Polypropylene Films by Multiple Headspace Solid Phase Microextraction–Gas Chromatography

Essential oils (EOs) are promising substances to be incorporated in food packaging materials as antioxidant and/or antimicrobial agents in active packaging systems. Once incorporated into the materials, their constituent compounds diffuse through the material. However, there is little information about the diffusion behaviour of EOs in plastics, and this is one of the major drawbacks in the design of active packaging relying on EOs as active agents. This study presents a new method for studying the diffusion of basil, citronella, oregano and rosemary EOs into plastic films. Diffusion assays of EOs from a coated polypropylene (PP) film into a stack of virgin PP films were conducted by the Moisan method using up to 10 layers of PP. Direct quantification of diffused analytes from the plastic sheets was performed by multiple headspace solid phase microextraction–gas chromatography–mass spectrometry. The fitting of experimental data for the main EO components with a Fickian model gave diffusion and partition (between active and virgin PP) coefficients, which are discussed under the light of some intrinsic factors contributing to the diffusion process. The results demonstrate the dependence of diffusion and partition coefficients on the initial concentration of EO components in the coated films, on their molecular weight and on their polarity. In particular, for similar molecular weight and initial concentration, a higher polarity is responsible for a faster diffusion, whereas lower polarity determines the retention of the EO component in the coating layer. Copyright © 2012 John Wiley & Sons, Ltd.     

聚乙烯醇/蒙脱土/山梨酸钾活性包装膜制备及释放

目的 通过制备聚乙烯醇（PVA）/蒙脱土（MMT）/山梨酸钾活性包装膜,考察其包装性能及山梨酸钾在膜材内的释放效果。方法 通过流延法制备含有不同浓度MMT的聚乙烯醇/山梨酸钾活性包装膜,分析活性包装膜的色度、透明度、拉伸性能和含水量,同时研究山酸钾在活性膜内向脂肪性食品模拟物中的释放行为。结果 通过添加MMT改善膜材的包装性能,MMT的添加在显著提高PVA膜拉伸强度的同时还降低了PVA膜的断裂伸长率,加深了膜材的色度,降低了膜的透明度;PVA膜的含水率随着MMT浓度的提高而降低。MMT的添加可明显改变山梨酸钾向脂肪类模拟物的释放行为,当MMT的质量分数为2%时明显地降低了山梨酸钾的释放量。结论 通过调整膜内MMT的浓度可以改变活性膜的色度、拉伸强度、含水量及膜内山梨酸钾的释放行为;使用Fickian第二定律模拟山梨酸钾释放是可靠的,可为山梨酸钾抗菌包装材料的进一步开发利用提供参考。     

Controlled Release of Mangiferin Using Ethylene Vinyl Acetate Matrix for Antioxidant Packaging

This study investigated the use of ethylene vinyl acetate (EVA) matrix in controlled release packaging. Mangiferin, having high antioxidant activity, was incorporated into the EVA matrix with different vinyl acetate (VA) contents. Mangiferin release rate increased with increasing VA content (or decreasing crystallinity). Linear relationship between mangiferin release rate and VA content was observed in the range of 18–40% VA. The diffusion coefficients of mangiferin released from the EVA matrices containing 12%, 18%, 25% and 40% VA were 0.482, 0.512, 2.81 and 2.88 (×10^?14 m²/s), respectively. The enhancement factors of about 22‐fold and sevenfold were observed in the 12% and 18% VA matrices, respectively, when using triethyl citrate as a plasticizer. EVA film containing 40% VA had the highest antioxidant activity (81.90% radical scavenging capacity, (RSC)) because the highest amount of mangiferin was released in the food simulant (84.66 µg/ml). Addition of mangiferin in the polymer matrices had no significant (p > 0.05) effect on thermal and barrier properties of the films but decreased tensile strength and Young's modulus. The results of this study demonstrated that EVA matrices with varying degree of VA could potentially be used to control mangiferin release rate for antioxidant packaging. Copyright © 2014 John Wiley & Sons, Ltd.     

Migration of di‐(2‐ethylhexyl)adipate (DEHA) and acetyl tributyl citrate (ATBC) plasticizers from PVC film into the food stimulant of isooctane

Chemical migration from food packing is influenced by several factors such as nature of chemicals, complexity of food, temperature, packing material used and properties of the migrating substances. Chemical compounds that are incorporated within polymeric packaging materials may interact with food components during processing or storage and migrate into the food by jeopardizing the food safety. This migration is higher if food remains in contact with packing material for extended time. Polyvinyl chloride (PVC) film such as di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC) are still widely used as a food packing material due to its flexibility, transparency and low water permeability. The present study covers the main migration phenomena of both plasticizers (di‐(2‐ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)) from PVC‐film into isooctane food stimulant using a direct gas chromatographic method. An exposure period of 48 h at 30 °C and 4 °C was used. The obtained results showed DEHA levels ranging of 7.2 mg/dm² while, no ATBC migration from PVC‐film was observed. Results are discussed in relation to EU legislation proposed upper limit for DEHA specific migration (18 mg/L or 3 mg/dm²) and overall migration limit (OM) of 10 mg/dm².     

Migration of Tinuvin P,a UV stabilizer,from PET bottles into fatty‐food simulants

Tinuvin P migration from Polyethyleneterephthalate (PET) bottles was investigated using several fatty‐food simulants such as olive oil, soybean oil, n‐heptane and iso‐octane, at exposure conditions of 2–10 days at 40°C (total immersion). The stability of several UV stabilizers (BHT, Cyasorb UV 5411, Tinuvin P, Tinuvin 326 and Tinuvin 327) in n‐heptane and iso‐octane was also studied. After 10 days at 40°C, losses of 6% and 10% in iso‐octane and n‐heptane respectively, were verified for Tinuvin P. Other UV stabilizers at the same experimental conditions showed higher losses (up to 30% for Tinuvin 327). These results confirm that, when carrying out specific migration studies, the stability of the substance of interest should be established in the food simulant to avoid underestimating the real migration behaviour. In order to quantify UV stabilizer migration, n‐heptane and iso‐octane solutions were concentrated and directly analysed by SIM mode GC–MS. For olive and soybean oils, Tinuvin P was isolated using size‐exclusion chromatography and quantified by SIM mode GC–MS. Iso‐octane proved to be a more suitable fatty‐food simulant than n‐heptane for the migration study of Tinuvin P from PET. Higher levels of Tinuvin P migrated to olive and soybean oils rather than to n‐heptane. These results suggest that the MERCOSUL recommended official methods for specific migration studies should be revised, since the migration levels using n‐heptane as a fatty‐food simulant could be underestimated when compared to edible oils. Copyright © 1999 John Wiley & Sons, Ltd.     

Effects of ionizing treatments on packaging -food simulant combinations

Research relating to ionizing treatment has been carried out on ‘food simulants polyethylene film’ combinations. Pouches have been irradiated by gamma photons or accelerated electrons at a 10kGy dose. Overall, the migration test has given some interesting results, particularly in the case of acid simulant, where a limit of validity has been found for the overall migration method. Many radiolytic products and degradation reactions have been indicated, and it has been established that the high permeability of packaging film to oxygen had influenced the radiolytic product yields. The results show some interactions between packaging film and food simulant under irradiation conditions.     

基于植物精油的抗菌活性包装在食品保鲜中的研究进展

目的 通过总结现有植物精油抗菌活性包装最新研究成果,为促进食品活性包装的进一步研究和应用提供指导。方法 介绍对食源性致病菌具有抑制作用的代表性植物精油及其主要化学成分;从破坏/影响细胞膜的结构及功能、遗传物质的复制、酶的活性和代谢功能等方面归纳总结植物精油对食源性致病菌的抑菌作用机制;分析总结植物精油活性包装材料的主要制备工艺;并介绍植物精油活性包装材料在食品保鲜中的最新应用成果;针对目前植物精油活性包装领域存在的问题提出解决方案。结论 部分具有抑菌作用的植物精油可作为化学合成防腐保鲜剂的有效替代品,随着精油在活性包装应用过程中存在的易挥发、有气味及食品安全风险等问题不断解决,植物精油活性包装将在食品保鲜领域具有良好的应用前景。     

The Barrier Effect of EVOH versus 1,4,7‐Triaxocyclotridecane‐8,13‐Dione,a Non‐intentionally Added Compound from Polyurethane Adhesives in Multilayer Food Packaging

The presence and migration of non‐intentionally added substances in food packaging materials are the big concerns nowadays in terms of food safety, and the identification and quantitation are an important analytical challenge. Among non‐intentionally added substances, 1,4,7‐trioxacyclotridecane‐8,13‐dione, a by‐product resulting from the interaction between ingredients in many polyurethane adhesives, has been identified and quantified. Migration tests were carried out with food simulant E (Tenax®) and 3% acetic acid (simulant B) stored at 40°C/10 days using different adhesives and with different film thickness in the presence and absence of EVOH layer. After the exposure, Tenax® was extracted and analysed by gas chromatography with mass spectrometry. For 3% acetic acid, the analyses were directly performed by the Acquity® ultra‐performance liquid chromatography system coupled to triple quadrupole mass spectrometer detector. A possible degradation of the lactone after migration tests with 3% acetic acid occurred, and total degradation after 8 days was confirmed. Two compounds were detected and identified, which were also found in the migration extracts. Partition experiments were carried out from laminates composed by polypropylene film, adhesive and non‐treated polyethylene film at 40°C for 10 days. After this, the polypropylene/adhesive and polyethylene layers were independently extracted and analysed by gas chromatography with mass spectrometry. Diffusion studies were carried out following the Moisan procedure. The results and conclusions are shown and discussed.     

Effect of processing method on migration of antioxidant from HDPE packaging into a fatty food simulant in terms of crystallinity

Migration of additives from plastic packaging into food products is generally considered to be affected by polymer crystallinity. In the present work, migration of Irganox 1010 from high density polyethylene into a fatty food simulant (ethanol 95%) was studied for samples prepared with different percent crystallinities. For this purpose, 2 different processing techniques, injection and compression molding, were used, and the preparation conditions were changed to obtain high density polyethylene samples with crystallinities in the range of 50 to 70%. Migration analysis was carried out at 121°C for 2 hours, and then at 40°C for 238 hours using high performance liquid chromatography. In general, the injection molded specimens had lower crystallinity and higher overall migration than the compression molded ones. A similar trend for both injection and compression molded samples was observed indicating that the overall migration was a function of crystallinity degree. However, the specific migration rates of Irganox 1010 especially before 50 hours were found to be different for the 2 processing methods because of dissimilar morphologies. Theoretical modeling based on Fickian diffusion was applied to give more insights into the involved processes during specific migration. The interaction of the food simulant with the polymer was taken into account considering the food sorption into the polymer. By fitting the model on experimental data, it was possible to obtain the model parameters such as partition coefficients (K) and the swelling constant (B) as a function of sample crystallinity.     

纸质包装材料中挥发性有机物迁移量的测定

目的研究纸质包装材料中挥发性有机物向食品模拟物中的迁移量。方法选取改性聚苯醚作为食品模拟物,首次建立模拟物MPPO直接顶空进样-气相色谱/质谱联用法测定包装用纸中23种有机挥发物质迁移量的方法。结果该法测定23种挥发性物质的相关系数R均大于0.998,相对标准偏差为1.4%~4.6%(n=7),检出限为0.03~0.60 mg/m2,加标回收率为81.2%~110.2%。结论该法无需前处理,简单快速,灵敏度高,重现性好,能满足包装用纸中23种有机挥发性物质迁移量的测定要求。     

Migration of alkylbenzenes from packaging into food and Tenax®

Alkylbenzenes (alkyl chain C₁₀–C₁₃) are used as solvent components in certain offset printing inks. Alkylbenzenes were identified from 10 out of 15 samples of offset‐printed food packaging made of board. Printed hamburger collars intended for hamburger restaurants had exceptionally high contents of alkylbenzenes (70–500 mg/kg). Most of the collars had varnish on both the printed surface and the non‐printed food contact surface. Migration of alkylbenzenes from the hamburger collar into a roll was 2 mg/kg. In another test, in which Tenax^® was used as simulant, the effect of a varnish layer on the food contact surface was studied. It was found that the varnish layer reduced migration by about 70%. Tests with Tenax^® as a food simulant resulted in higher migration than in tests with rolls. The European Commission has published a risk assessment report on alkylbenzenes. The report concludes that there is no need for further testing or for risk reduction measures beyond those which are currently applied. However, consumer exposure was calculated without taking into account the possibility of oral exposure to alkylbenzenes migrating from food packagings. The migration of alkylbenzenes thus merits further study. Copyright © 2001 John Wiley & Sons, Ltd.     

Novel Test Approach for Evaluating and Modelling Barrier Properties of Food Contact Materials Against Mineral Oil Contaminants

A method for testing the mineral oil barrier properties of packaging materials has been developed as a response for the concerns on contamination of food by mineral oil compounds. The aim was to provide an efficient tool to evaluate packaging materials with respect to this. The method is a modification of the so‐called cup test using model compounds comparable with mineral oil components with different length and configuration of the hydrocarbon chain. The model compounds are introduced in the gas phase as penetrants. The absorbed amounts, which have migrated through the barrier, are analysed from a food simulant or powdered sugar. The method has been validated for coated and non‐coated boards. Compared with folding boxboard without polymer coating, polyethylene terephthalate‐coated board reduces the amount of the C16 compound in food simulant after 7‐day tests by a factor of 30. An extended migration model describing sorption mechanisms to both food simulant and fibres in the packing material has been developed. The model simulations for folding boxboard indicate that fibres absorb a significant proportion of the compounds when molecular weight increases. This retards the migration significantly compared with the speed expected by diffusion mechanism only. Copyright © 2016 John Wiley & Sons, Ltd.     

食品接触材料PVC中32种增塑剂在4种食品模拟物中的迁移规律研究

在不同的条件下,将含有已知量增塑剂的PVC薄膜,在水、乙酸(体积分数为3%)、乙醇(体积分数10%)和橄榄油等4种食品模拟物中浸泡,在规定的时间点抽取一定量的浸泡液,采用气相色谱-质谱法测定增塑剂含量,研究迁移量及迁移率与时间、温度、模拟食品属性、增塑剂初始浓度及包装材料厚度等参数的关系。结果表明:食品模拟物的食品属性对增塑剂的迁移行为有显著影响;增塑剂溶出种类数、迁移量和迁移率随温度升高显著增加;薄膜厚度增加,则增塑剂迁移量大,迁移率降低;薄膜中增塑剂初始浓度高,则迁移量大,迁移率低。     

Properties of nisin‐incorporated polymer coatings as antimicrobial packaging materials

Nisin was incorporated into binder solutions of acrylic polymer and vinyl acetate‐ethylene co‐polymer, and then coated on to paper. Diffusive migration of incorporated nisin and the antimicrobial activity of the polymer coatings were investigated in order to understand the way of controlling nisin migration and the extent of microbial suppression by the coated paper. Vinyl acetate–ethylene co‐polymer exhibited a faster rate and higher degree of migration into aqueous food simulant solutions compared to acrylic polymer, and also exhibited a higher degree of suppression against Micrococcus flavus ATCC 10240 inoculated into the microbial medium. Addition of NaCl, sugar and citric acid to water significantly reduced the rate of diffusion of nisin in the case of acrylic polymer, while only slight change was observed due to the additive for vinyl acetate‐ethylene co‐polymer. The simulant type slightly affected the equilibrated migration level of nisin. When the nisin‐incorporated coatings were in contact with pasteurized milk and orange juice at 10°C, significant suppression of total aerobic bacteria and yeasts was observed without any noticeable difference between the two types of coatings. Copyright © 2002 John Wiley & Sons, Ltd.     

食品接触材料聚乙烯和聚丙烯中9种抗氧化剂在食品模拟物中的迁移规律研究

在不同条件下,将含有已知量抗氧化剂的聚乙烯和聚丙烯薄膜,在水、乙酸(3 g/L)、体积分数为10%,50%和95%的乙醇等5种食品模拟物中浸泡,在规定的时间点抽取一定量的浸泡液,采用超高效液相色谱法检测抗氧化剂含量,研究了迁移量及迁移率与时间、温度、模拟物属性、抗氧化剂初始浓度和聚丙烯材料的厚度等参数的关系。结果表明:食品模拟物的属性对抗氧化剂的迁移行为影响最大;迁移量和迁移率随温度的升高而增加;材料厚度增加,则抗氧化剂迁移量增加,而迁移率降低;薄膜中抗氧化剂初始浓度越高,则迁移量越大,迁移率越低。     

Effects of PP‐based Nanopackaging on the Overall Quality and Shelf Life of Ready‐to‐eat Salami

A total of 1% nanoclay containing polypropylene (PP)‐nanocomposite and 1% nanoclay plus 5% poly‐beta‐pinene (PβP) containing PP‐active‐nanocomposite materials were produced and tested for packaging of sliced salami. The sliced salami was packaged using both nanofilms and multilayer film of PP/PA/EVOH/PE under vacuum, modified atmosphere packaging under 50% CO₂ and 50% N₂ and air and stored at 4 °C for 90 days. During storage, headspace gas composition; microbial, physical and chemical analyses; and sensory evaluation were performed. The antimicrobial effect of PβP containing nanomaterial was pronounced under vacuum, and no bacterial growth was observed for 75 days. An a* value decreased notably in all applications during storage and preserved best by the multilayered material under vacuum and high CO₂. Thiobarbituric acid reactive substances (TBARS) were 0.63 mg MDA/kg after the processing and gradually increased at all applications during increased storage. TBARS values of all vacuum applications were lower than that of modified atmosphere packaging applications. Rancid taste development was determined by sensory panelists when TBARS values were higher than 0.80 mg MDA/kg on the 90th day. There was no significant moisture loss, and no increase in hardness was determined during the whole storage time. The longest shelf life was 75 days for the sliced salami under vacuum and high CO₂ using the multilayer material. PβP containing nanomaterial provided 50 days of shelf life under vacuum, which is commercially considerable. Copyright © 2017 John Wiley & Sons, Ltd.     

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.     

微波条件下PVC食品保鲜膜中DNBP在水基模拟物中的迁移行为研究

以气相色谱-质谱联用技术为分析手段,研究了在微波条件下PVC食品保鲜膜中DNBP在3种水基食品模拟物中的迁移规律。实验结果表明,DNBP的迁移量随微波功率、加热时间和加热温度的增加而增大,并与食品模拟物的种类有关;当加热温度和加热时间相同时,微波加热条件下DNBP在3种食品模拟物中的迁移量均高于常规加热方式。     

Properties of antimicrobial plastics containing traditional food preservatives

Traditional food preservatives, sodium benzoate, sodium nitrite, potassium sorbate and sodium lactate, were incorporated into synthetic plastics, low‐density polyethylene (LDPE), poly(maleic acid‐co‐olefine), polystyrene (PS) and polyethylene terephthalate (PET), aimed at producing antimicrobial packaging material for foodstuffs. The study was undertaken on plaques (thickness 2 mm) and films (thickness 70–120 µm), whose antimicrobial test results clearly differed. Plaques containing 15% sodium nitrite inhibited both Aspergillus niger and Bacillus subtilis, whereas the same concentration of sodium benzoate and potassium sorbate had activity only against B. subtilis. Sodium lactate‐containing samples did not have any antimicrobial activity and none of the samples inhibited Escherichia coli. Antimicrobial substances added into PS and PET produced the strongest activities; however, due to the brittle structure of these materials, they were not tested further. Thus, more thorough tests for antimicrobial activity, migration and oxygen and water vapour permeability were carried out using LDPE films with 2.5–15% sodium benzoate and sodium nitrite. The effects of both substances on permeability properties were negligible. Although the total migration into food simulants measured from the films in many cases exceeded the limit value of 10 mg/dm², no antimicrobial activity was observed. Copyright © 2003 John Wiley & Sons, Ltd.