Current status of biobased and biodegradable food packaging materials: Impact on food quality and effect of innovative processing technologies

Fossil-based plastic materials are an integral part of modern life. In food packaging, plastics have a highly important function in preserving food quality and safety, ensuring adequate shelf life, and thereby contributing to limiting food waste. Meanwhile, the global stream of plastics into the oceans is increasing exponentially, triggering worldwide concerns for the environment. There is an urgent need to reduce the environmental impacts of packaging waste, a matter raising increasing consumer awareness. Shifting part of the focus toward packaging materials from renewable resources is one promising strategy. This review provides an overview of the status and future of biobased and biodegradable films used for food packaging applications, highlighting the effects on food shelf life and quality. Potentials, limitations, and promising modifications of selected synthetic biopolymers; polylactic acid, polybutylene succinate, and polyhydroxyalkanoate; and natural biopolymers such as cellulose, starch, chitosan, alginate, gelatine, whey, and soy protein are discussed. Further, this review provides insight into the connection between biobased packaging materials and innovative technologies such as high pressure, cold plasma, microwave, ultrasound, and ultraviolet light. The potential for utilizing such technologies to improve biomaterial barrier and mechanical properties as well as to aid in improving overall shelf life for the packaging system by in-pack processing is elaborated on.     

Estimation of exposure to food packaging materials. 1: Development of a food-packaging database

A food-packaging database was developed to provide qualitative information on the types of packaging materials used for foods. Packaging information was collected from a sample of 594 children aged 5-12 years as part of a national children's food survey carried out in Ireland during 2003-04. All the food packaging collected during the survey was forwarded to the coordinating centre for further analysis and entry into the Irish Food Packaging Database. The database was created in Microsoft Access® and stored information on: the brand of the food, the packaging type, the unit weight, the contact layer, the European Union food type (i.e. aqueous, acidic, alcoholic or fatty) and other relevant parameters. Of the 5551 different brand foods consumed by children in the food survey, packaging information was collected on 3441 (62%). As some brand foods had different unit weights and packaging formats, there was duplication of some brand foods in the database to account for this fact. Therefore, there were 3672 packaging entries in the database. Of these, plastics were the most common packaging contact layer (n = 2874, 78.3%). Multimaterial multilayers with a plastic contact layer accounted for 459 (12.5%) entries. Polyethylene was the most frequently used contact layer (n = 941), with polypropylene a close second (n = 809). This database is unique in Europe for the quality and amount of food packaging information it contains and could be used to develop packaging use factors for a more refined exposure assessment to food packaging materials in the European Union.     

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

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

Active Packaging Applications for Food

The traditional role of food packaging is continuing to evolve in response to changing market needs. Current drivers such as consumer's demand for safer, “healthier,” and higher‐quality foods, ideally with a long shelf‐life; the demand for convenient and transparent packaging, and the preference for more sustainable packaging materials, have led to the development of new packaging technologies, such as active packaging (AP). As defined in the European regulation (EC) No 450/2009, AP systems are designed to “deliberately incorporate components that would release or absorb substances into or from the packaged food or the environment surrounding the food.” Active packaging materials are thereby “intended to extend the shelf‐life or to maintain or improve the condition of packaged food.” Although extensive research on AP technologies is being undertaken, many of these technologies have not yet been implemented successfully in commercial food packaging systems. Broad communication of their benefits in food product applications will facilitate the successful development and market introduction. In this review, an overview of AP technologies, such as antimicrobial, antioxidant or carbon dioxide‐releasing systems, and systems absorbing oxygen, moisture or ethylene, is provided, and, in particular, scientific publications illustrating the benefits of such technologies for specific food products are reviewed. Furthermore, the challenges in applying such AP technologies to food systems and the anticipated direction of future developments are discussed. This review will provide food and packaging scientists with a thorough understanding of the benefits of AP technologies when applied to specific foods and hence can assist in accelerating commercial adoption.     

塑料食品包装材料中有毒有害化学残留物及分析方法

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

Recent advances in biobased and biodegradable polymer nanocomposites,nanoparticles, and natural antioxidants for antibacterial and antioxidant food packaging applications

Inorganic nanoparticles (NPs) and natural antioxidant compounds are an emerging trend in the food industry. Incorporating these substances in biobased and biodegradable matrices as polysaccharides (e.g., starch, cellulose, and chitosan) and proteins has highlighted the potential in active food packaging applications due to more significant antimicrobial, antioxidant, UV blocking, oxygen scavenging, water vapor permeability effects, and low environmental impact. In recent years, the migration of metal NPs and metal oxides in food contact packaging and their toxicological potential have raised concerns about the safety of the nanomaterials. In this review, we provide a comprehensive overview of the main biobased and biodegradable polymer nanocomposites, inorganic NPs, natural antioxidants, and their potential use in active food packaging. The intrinsic properties of NPs and natural antioxidant actives in packaging materials are evaluated to extend shelf-life, safety, and food quality. Toxicological and safety aspects of inorganic NPs are highlighted to understand the current controversy on applying some nanomaterials in food packaging. The synergism of inorganic NPs and plant-derived natural antioxidant actives (e.g., vitamins, polyphenols, and carotenoids) and essential oils (EOs) potentiated the antibacterial and antioxidant properties of biodegradable nanocomposite films. Biodegradable packaging films based on green NPs—this is biosynthesized from plant extracts–showed suitable mechanical and barrier properties and had a lower environmental impact and offered efficient food protection. Furthermore, AgNPs and TiO₂ NPs released metal ions from packaging into contents insufficiently to cause harm to human cells, which could be helpful to understanding critical gaps and provide progress in the packaging field.     

纳米塑料复合食品包装中的纳米成分及其迁移研究进展

在塑料食品包装中加入纳米材料可以实现很好的机械性、气体阻隔性或抗菌性等优良性能。然而在与食品 接触的过程中这些纳米材料也有可能迁移到食品中,从而对消费者的健康产生威胁,甚至对市场及消费者信心造成 负面影响。对纳米材料进行迁移研究是对其进行风险评估的重要一环,已经得到国内外学者的广泛关注。本文综述 了纳米塑料复合包装的种类、在食品包装中应用较多的纳米材料及其作用,并详细分析了食品包装中纳米材料向食 品或食品模拟物迁移的研究。结果表明：食品包装中纳米材料向食品或食品模拟释放的量较小,但到目前为止,关 于它们是否会以纳米形态释放出来仍然没有达成统一意见。另外,微波处理、塑料助剂的添加可以影响纳米材料的 释放。     

Recycled paper–paperboard for food contact materials: Contaminants suspected and migration into foods and food simulant

Contaminant residues in food packaging is a new challenge of our time, as it may pose a threat for consumers. Higher levels of contaminants were observed in food packaging made by recycled materials, even if little information is available for some groups of contaminants. The present study proposes a procedure for analyzing three different groups of organic contaminants in recycled paper and paperboard. Seventeen commercial samples were analyzed for the presence of bisphenol A (BPA), bis (2-ethylhexyl) phthalate (DEHP), nonylphenol monoethoxylate (NMP) and nonylphenol di-ethoxilate (NDP). Not all the samples contained all the contaminants; BPA was the only substance present in all the samples. The concentrations detected were quite high and, in most of the cases, in agreement with results reported in previous studies. Substance migration tests from spiked/non-spiked samples for two dry foods and Tenax® food simulant were undertaken. BPA migration quotients were always lower than 1%, whereas the migration quotients of DEHP were higher than 2.0%. The highest nonylphenols migration quotients were 6.5% for NMP and 8.2% for NDP. Tenax® simulates well the contaminants migration from paperboard to dry food, in some cases being even more severe than the food.     

食品无菌包装技术研究进展

随着新型多聚材料和抗菌材料的出现,当今食品行业中将抗菌材料应用于食品无菌包装成为新的研究热点。本文介绍了国际上多种先进的将抗菌多聚物应用于食品包装的方法,以及它们在商业上的应用,并展望未来的无菌包装技术。     

Microbial control by packaging: a review

Since early man first used a variety of natural containers to store and eat foods, significant developments in food packaging materials have provided the means to suppress microbial growth as well as protect foods from external microbial contamination. Throughout this progression, packaging materials have been developed specifically to prevent the deterioration of foods resulting from exposure to air, moisture, or pH changes associated with the food or the surrounding atmosphere. Both flexible and rigid packaging materials, alone or in combination with other preservation methods, have been developed to offer the necessary barrier, inactivation, and containment properties required for successful food packaging. Examples of flexible packaging used to inactivate microorganisms associated with foods include controlled atmosphere, vacuum, modified atmosphere, active, and edible packaging. Additionally, the combination of rigid packaging materials made from metal, glass, or plastic with heat provides the most effective and widely used method for inactivating microorganisms. As with all food products, it is necessary to integrate a HACCP-based program to assure quality throughout the packaging operation. In addition to packaging improvements, other novel technologies include the development of detectors for oxygen levels, bacterial toxins, and microbial growth, or the integration of time-temperature indicators for detection of improper handling or storage.     

Physical and Mechanical Properties of Biobased Materials Starch,Polylactate and Polyhydroxybutyrate

Commercial and semi‐commercial biobased materials (Polylactate, PLA, polyhydroxy‐butyrate, PHB, wheat starch and corn starch) were investigated. Physical and mechanical characterisation (tensile strength, elongation, tear strength, compression, gas permeability (CO₂ and O₂) and water vapour permeability (WVP)) was examined. Tests on both films and cups show potential use of these materials for primary food packaging, especially PLA and PHB. An interesting O₂:CO₂ permeability ratio (1:7 to 1:12) was seen, which make these materials suitable for packaging of food with high respiration. The mechanical properties were comparable to conventional materials such as polyethylene (PE) and polystyrene (PS). The WVP measured on films ranged from 12.6 to 18.6 [g H₂O/(m² ? 24h)], and on cups the range was 2.2 to 10.5 [g H₂O ? 700 μm/(m² ? 24h)]. The WVP for the starch‐based materials seems to be the most crucial parameter, and needs improvement if these materials are to be used as food packaging.     

食品包装材料的安全性及其对策

简述了当前食品包装材料的安全现状,初步分析食品包装材料的安全性问题产生的原因和对人类健康的危害,就加强我国食品包装材料工作、建立中国食品包装材料安全质量控制体系提出了具体建议.     

Effectiveness of antimicrobial food packaging materials

Antimicrobial additives have been used successfully for many years as direct food additives. The literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. Antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and Frankfurter sausages (hot dogs). The use of such packaging materials is not meant to be a substitute for good sanitation practices, but it should enhance the safety of food as an additional hurdle for the growth of pathogenic and/or spoilage microorganisms. Studies have focused on establishing methods for coating low-density polyethylene film or barrier films with methyl cellulose as a carrier for nisin. These films have significantly reduced the presence of Listeria monocytogenes in solutions and in vacuum packaged hot dogs. Other research has focused on the use of chitosan to inhibit L. monocytogenes and chlorine dioxide sachets for the reduction of Salmonella on modified atmosphere-packaged fresh chicken breasts. Overall, antimicrobial packaging shows promise as an effective method for the inhibition of certain bacteria in foods, but barriers to their commercial implementation continue to exist.     

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。     

High throughput non-destructive assessment of quality and safety of packaged food products using phosphorescent oxygen sensors

Intelligent and active packaging technologies have gained attention in recent time due to increased demand by the consumers and manufacturers for sustaining the quality and safety of food products, improved shelf-life as well as real time monitoring of the packaging, storage and handling processes. In this context, phosphorescence based sensors for molecular oxygen (O₂) are important tools for monitoring of packaged products, new product development and optimisation. They allow fast, reversible, real-time and quantitative monitoring of residual O₂ levels in a non-destructive manner, being superior over alternative systems. In this review, we describe the main types of phosphorescent O₂-sensitive materials, fabrication methods and general requirements for sensors for food packaging applications. The main developments and representative examples are provided which illustrate the application of such sensors for monitoring of gaseous and dissolved O₂ in various types of packaged foods and beverages. We also compare commercial O₂ sensing instrumentation and disposable O₂ sensors currently in use.     

Perspectives for chitosan based antimicrobial films in food applications

Recently, increasing attention has been paid to develop and test films with antimicrobial properties in order to improve food safety and shelf life. Active biomolecules such as chitosan and its derivatives have a significant role in food application area in view of recent outbreaks of contaminations associated with food products as well as growing concerns regarding the negative environmental impact of packaging materials currently in use. Chitosan has a great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, non-toxicity and versatile chemical and physical properties. Thus, chitosan based films have proven to be very effective in food preservation. The presence of amino group in C2 position of chitosan provides major functionality towards biotechnological needs, particularly, in food applications. Chitosan based polymeric materials can be formed into fibers, films, gels, sponges, beads or even nanoparticles. Chitosan films have shown potential to be used as a packaging material for the quality preservation of a variety of food. Besides, chitosan has widely been used in antimicrobial films to provide edible protective coating, in dipping and spraying for the food products due to its antimicrobial properties. Chitosan has exhibited high antimicrobial activity against a wide variety of pathogenic and spoilage microorganisms, including fungi, and Gram-positive and Gram-negative bacteria. The present review aims to highlight various preparative methods and antimicrobial activity including the mechanism of the antimicrobial action of chitosan based films. The optimisation of the biocidic properties of these so called biocomposites films and role of biocatalysts in improvement of quality and shelf life of foods has been discussed.     

Nano‐Food Packaging: An Overview of Market,Migration Research,and Safety Regulations

Recently, food packages produced with nanoparticles, “nano‐food packaging,” have become more available in the current market. However, although the use of nanomaterials is increasing in food packaging applications, concern over toxicity affects consumer perceptions and acceptance. Quite a number of commercialized forms of nano‐food packaging are coated or composited product with inorganic materials, for example, nanosilver and nanoclay as representative examples. Several studies have shown the possibility of nanomaterial migration from packaging or containers to foodstuff. The debate is still ongoing among researchers about the extent of migration and whether it is negligible and safe. Government agencies and stakeholders must hurry to determine use limitations and release conclusive legislation and regulations as soon as possible since nano‐food packaging may have great impacts on human health. This paper aims to review the availability of nano‐food packaging in the current market, report case studies on nanomaterial migration, and present the current status of safety regulations and management of nano‐food packaging in leading countries across regions. This review should enable governments and researchers to develop further nanomaterial risk assessment studies.     

Active food packaging technologies

Active packaging technologies offer new opportunities for the food industry, in the preservation of foods. Important active packaging systems currently known to date, including oxygen scavengers, carbon dioxide emitters/absorbers, moisture absorbers, ethylene absorbers, ethanol emitters, flavor releasing/absorbing systems, time-temperature indicators, and antimicrobial containing films, are reviewed. The principle of operation of each active system is briefly explained. Recent technological advances in active packaging are discussed, and food related applications are presented. The effects of active packaging systems on food quality and safety are cited.     

Packaging under pressure: Effects of high pressure, high temperature processing on the barrier properties of commonly available packaging materials

High pressure thermal (HPT) processing has the potential to deliver quality benefits to a range of processed foods. By exploiting the rapid temperature increase/decrease that accompanies pressurization/depressurization, commercial sterilization of foods can potentially be achieved by HPT with an overall reduced thermal exposure compared with conventional thermal processing technologies. High pressure thermal sterilization (HPTS) of foods is yet to be commercialized, but during development of the technology some potential limitations have been raised about the suitability for HPTS of commercially available packaging materials developed for retort processing. Key requirements of packaging materials for thermally processed foods are the preservation of oxygen and water barriers during processing and for the duration of the shelf life of the food. We examined the barrier properties after HPT processing of eleven commercially available packaging materials developed for conventional thermal sterilization processes. We found that the barrier properties of vapor-deposited oxide and nylon containing films were compromised by the combination of high pressure (600 MPa) and high temperature ( 110 °C) which would be reasonably expected to be required to render food commercially sterile by HPT processing. However, the barrier properties of aluminium foil and PVDC–MA containing films were not significantly affected by HPT processing. All materials suffered cosmetic deformation of the outer surface to some degree and mechanisms for these changes are proposed.

Industrial relevance

Information on the barrier properties of flexible packaging suitable for foods sterilized by HPT processing has been scarcely reported. This study provides information on the barrier properties of commercially available, retortable films processed under high pressure/high temperature conditions and identifies candidate packaging based on barrier performance.