Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents

Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.     

Requirements for foods packaged in polymeric films∗

The requirements for barrier properties of packaging materials against environmental factors vary with food products. The chemical, physical, and biological mechanisms of food deterioration due to environmental factors, vital properties required in packaging materials, and developments in progress and future trends to maintain the required standard of food quality have been critically reviewed. Theoretical and experimental results for a variety of food products in relation to the properties of the packaging materials are discussed. Methods of prediction of food stability and their industrial applications are also emphasized by specific examples.     

Potential of Immobilization Technology in Bacteriocin Production and Antimicrobial Packaging

Globalization of food trade, increasing demand for ready to eat fresh food products, and awareness among consumers towards side effects of chemical preservatives have led to research and development in the area of biopreservation. Biopreservation basically involves inhibition or killing of food spoilage microorganisms by the application of other microbes or their antimicrobial products. Bacteriocins are ribosomally synthesized peptides having potential as biopreservatives. The enhanced, stable, continuous, and economically viable production of these preservatives can be carried out by employing immobilization technology. Various matrices, operational conditions, and fermentation systems have been explored for achieving maximum bacteriocin production through immobilization; besides these, immobilization can be used for the application of bacteriocins in various packaging materials or films for their functional effects at the surface of different food products. Efficiency of an antimicrobial packaging system can be increased by its application in combination with other methods, including high-pressure processing (HPP), which in turn can improve the shelf life of food products. These antimicrobial packaging systems can play a significant role in extending shelf life of food products by reducing the risk of foodborne pathogens, thereby enhancing their quality and safety.     

新型食品包装材料的发展概况及趋势

食品包装是食品的外部保护, 可以防止食品免受外界因素的影响而发生感官或营养成分的变化。传统的食品包装材料不仅会给环境带来巨大压力, 而且从食品包装迁移至食品中的化学物质也会给食品安全和质量带来负面影响。随着人们对食品包装材料的安全性越来越关注, 很多新型的食品包装材料成为研究热点。本文对几种具有较大应用前景的可降解材料、可食材料进行了综述, 包括天然高分子材料、微生物合成高分子材料、聚乳酸(poly lactic acid, PLA)等新型食品包装材料的研究现状和亟待解决的问题, 简要介绍了活性包装和智能包装的发展, 并对未来食品包装的发展趋势提出方向。     

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.     

Importance of surface tension characterization for food, pharmaceutical and packaging products: a review

This article reviews the various theoretical approaches that have been developed for determination of the surface tension of solids, and the applications to food industrial products. The surface tension of a solid is a characteristic of surface properties and interfacial interactions such as adsorption, wetting or adhesion. The knowledge of surface tension is thus of great interest for every domain involved in understanding these mechanisms, which recover a lot of industrial investigations. Indeed, it is the case for the packaging industry, the food materials science, the biomedical applications and the pharmaceutical products, cleaning, adhesive technology, painting, coating and more generally all fields in relation with wettability of their systems. There is however no direct method for measurements of surface tension of solids, except the contact angle measurements combined with an appropriate theoretical approach are indirect methods for estimation of surface tension of solids. Moreover, since the publication by Young (1805) who developed the basis of the theory of contact angle some two hundred years ago, measurements and interpretations are still discussed in scientific literature, pointing out the need to better understand the fundamental mechanisms of solid-liquid interfacial interactions. Applications of surface tension characterization in the field of food materials science are detailed, especially for packaging and coating applications, which recover different actual orientations in order to improve process and quality.     

食品和药品接触材料聚丙烯中添加剂及 物质迁移的液相色谱分析

聚丙烯(PP)塑料被广泛用在食品及药品的包装上,PP中有害物质的迁移现已成为食品及药品安全隐患的重要组成部分,当食品与包装材料直接接触时,残留在PP包装材料里的抗氧剂及分解产物可以迁移到食品中污染食品。由于食品的多样性,因此常用几种食品模拟液来代替食品在实验室各种控制条件下进行迁移试验,因为迁移到模拟液里的添加剂浓度非常小,其浓度的测定常使用灵敏度较高的高效液相色谱法。迁移受到很多因素的影响,比如:接触的时间温度、接触的方式、包装材料的类型、迁移物的性质等。本文综述了聚丙烯包装材料有害物质迁移的研究现状,为我国食品包装行业标准化体系的建立提供一定的理论依据。     

中国出台进出口食品包装新规

食品包装安全卫生已受到越来越广泛的重视。2005年1至10月,欧盟向我国通报了54起食品包装及接触材料的安全卫生问题。2005年7月1日,欧委会健康和消费者保护总司司长马德林专门就我国出口欧盟与食品接触材料频繁被检出安全卫生问题致函我国驻欧盟大使,提出如果中方不在7月底前采取有效措施,将对中国的此类产品采取进一步措施。食品包装及接触材料已经成为发达国家设立技术壁垒的新领域。近年来,欧盟、美国、日本等对直接与食品接触的包装及包装材料都制定了详细的法规。如FDA长期以来遵循的美国联邦法规,详细规定了各种与食品直接或间接接触的包装材料及其中所使用的各项物质的要求。欧盟在2004年新拟定的草案“食品接触物质超级指令”则进一步综合了过去所有与食品接触物质相关的旧法规,使其成为欧盟对食品包装材料最主要而且最具影响力的新法规。     

金属有机框架材料在食品包装中的应用

随着食品工业的发展,食品安全问题引起人们的广泛关注。金属有机框架（metal-organic frameworks,MOFs）是一类具有独特物理和化学性质的功能材料,其具有多孔结构以及显著的抗菌性能,因此在食品保鲜方面显示出良好的应用前景。在食品包装领域,MOFs可以延长食品的保质期并延缓贮藏期食品品质的劣变,提高食品包装材料的性能。本文综述MOFs作为抗菌剂、氧清除剂和乙烯清除剂在食品包装中的应用,介绍MOFs在食品包装领域的应用前景及面临的问题,旨在为MOFs在食品包装中的应用提供参考。     

控释技术在食品活性包装中应用与研究

食品包装控释系统是指包装材料作为传送系统进行活性物质的控制释放,目的在于维持或改善包装内食品的品质。本文阐述控释技术在食品活性包装中的应用、活性物质释放机理、释放速率影响因素等最新研究进展,展望控释技术未来的研究方向。     

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.     

Natural antimicrobials and antioxidants added to polylactic acid packaging films. Part I: Polymer processing techniques

Currently, reducing packaging plastic waste and food losses are concerning topics in the food packaging industry. As an alternative for these challenges, antimicrobial and antioxidant materials have been developed by incorporating active agents (AAs) into biodegradable polymers to extend the food shelf life. In this context, developing biodegradable active materials based on polylactic acid (PLA) and natural compounds are a great alternative to maintain food safety and non-toxicity of the packaging. AAs, such as essential oils and polyphenols, have been added mainly as antimicrobial and antioxidant natural compounds in PLA packaging. In this review, current techniques used to develop active PLA packaging films were described in order to critically compare their feasibility, advantages, limitations, and relevant processing aspects. The analysis was focused on the processing conditions, such as operation variables and stages, and factors related to the AAs, such as their concentrations, weight losses during processing, and incorporation technique, among others. Recent developments of active PLA-based monolayers and bi- or multilayer films were also considered. In addition, patents on inventions and technologies on active PLA-based films for food packaging were reviewed. This review highlights that the selection of the processing technique and conditions to obtain active PLA depends on the type of the AA regarding its volatility, solubility, and thermosensitivity.     

2019年上海市微波食品包装中邻苯二甲酸酯类塑化剂迁移风险监测

目的 评估微波食品包装中的邻苯二甲酸酯类(phthalic acid esters, PAEs)塑化剂至食品中的迁移风险进行。方法 采集90批次微波加热食品, 依据GB 31604.30-2016《食品安全国家标准 食品接触材料及制品中邻苯二甲酸酯的测定和迁移量的测定》, 采用气相色谱-质谱法(gas chromatography-mass spectrometry, GC/MS)对样品中的PAEs含量进行检测, 并考察样品中PAEs的迁移风险。结果 90批次微波加热食品包装中, 共计有18批次样品中检出PAEs增塑剂, 检出率为20%。其中15批次样品检出含量在0~10 mg/kg范围内, 最高检出含量为29.86 mg/kg。迁移实验未检出有塑化剂的迁移。结论 2019年上海市微波食品包装引入塑化剂污染的风险较低, 正常使用过程中迁移风险较小。     

Release of 1-methylcyclopropene from heat-pressed polymer films

ABSTRACT:  Gaseous 1-methylcyclopropene (1-MCP) is an inhibitor of ethylene perception that is being used extensively for apples and ornamental products, and under intensive investigation for its potential benefits for other fruits and vegetables. 1-MCP is currently used in closed environments that maintain stable concentrations for several hours in order to be effective. However, food packaging materials that release 1-MCP at a predictable rate into the package headspace might be useful for application in inhibiting the deleterious effects of ethylene in the postharvest packaging and storage of some horticultural products. A 1-MCP/α-cyclodextrin (1-MCP–cd) complex was incorporated into several common packaging films by heat-pressing (dry-blend, lamination) and solution-casting methods. The release of 1-MCP from the films was quantified by gas chromatography with respect to time, loading of 1-MCP, temperature, relative humidity (RH), type of film, and film-forming method. Release of 1-MCP was rapid and high in films held at RH ≥ 75%. The rate of release was slow during the 1st 12 h and then increased during the next 24 to 36 h. Higher temperatures resulted in higher and faster release. A loading of 8 mg of 1-MCP–cd per 140 mg of polymer was found to be optimal. Pressing 1-MCP–cd containing films above 100 °C reduced the amount of 1-MCP remaining in the film. Incorporation into LDPE resulted in a higher and faster release than from PS, PVC, and PP polymers. 1-MCP release from a film matrix appears to be within the acceptable range for produce packaging applications.     

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.     

Kinetic desorption models for the release of nanosilver from an experimental nanosilver coating on polystyrene food packaging

To predict the kinetic desorption of silver from an experimental nanosilver coated polystyrene food packaging material into food simulants (0, 1, 2 and 3% acetic acid (HAc) in distilled water (dH₂O)) at 4 temperatures (10, 20, 40 and 70 °C), 5 sorption models were examined for their performance. A pseudo-second order kinetic sorption model was found to provide the best prediction of an unseen desorption validation dataset with R² = 0.90 and RMSE = 3.21. Poor predictions were witnessed for desorption at 70 °C, potentially due to re-adsorption of the silver back onto the polystyrene substrate, as shown in the kinetic migration experiments. Similarly, the temperature dependence of the desorption rate constant was satisfactorily described using the Arrhenius equation with the exception of the 70 °C scenario. The use of sorption models identified scenarios that may limit human exposure to nanosilver migrating from this experimental nanocoating, i.e. low temperature applications.Industrial relevanceThe use of antimicrobial packaging has the potential to reduce food spoilage and risk from pathogenic microorganisms while reducing food waste by extending the shelf life of food products. Coating of antimicrobial silver nanoparticles (AgNPs) to polymer surfaces is a highly advantageous technology as microbial contamination predominantly occurs on the surface of fresh and processed food products. However, uncertainty related to the potential release of nanoparticles from food packaging materials, subsequent potential human exposure and toxicology is a barrier to the uptake of these novel materials. In the European Union, where the safety assessment of these materials is stringent, mathematical models used to predict the worst case migration of nanoparticles from food packaging materials have supported the acceptance of some nanomaterials for use in food packaging. The performance of a number of desorption models was evaluated to predict the release of AgNPs from AgNP coated polystyrene. The model identified factors that influenced migration and possible industrial applications for the developed material to minimise human exposure. The study highlights the potential benefits of using predictive models to assess migration of NPs from polymers into food simulants instead of time consuming and expensive migration studies.     

我国食品及包装机械面临产业升级——访中国食品和包装机械工业协会副会长 何南至

<正> 我国食品工业和食品包装机械真正形成行业也就20年的时间。这20年是世界技术发展最快的时期,新技术不断在行业上应用,而我国食品工业整体基础薄弱,技术及科研力量不足,因而造成我国食品机械工业的发展相对滞后。大量技术含量高的成套食品机械设备仍依靠进口。要改变这种状况,我国食品机械面临产业升级。日前,记者特别专访了中国食品和包装机械工业协会副会长何南至,倾听他的独到见解。     

Study of the Degradation Products Formed During Extrusion Lamination of an lonomer

Headspace concentration techniques were used to tentatively identify the volatile products formed during the extrusion process of thermoplastic polymers to produce ionomers which have many applications as food packaging materials. Compounds representing alcohols, aldehydes, ketones, and hydrocarbons were tentatively identified. Time/temperature studies showed that the quantity of compounds formed depended on the conditions used for resin processing. The rate of release of compounds was also found to be temperature dependent. Sensory evaluation data confirmed the instrumental findings.     

静电纺丝纳米纤维在食品领域中的应用进展

静电纺丝纳米纤维由于具有高比表面积、高孔隙率、制备简单、可控性良好、易功能化、仪器便宜、工艺简单、对材料要求低、可以实现工业化生产等特点,已经被广泛应用于食品科技领域的研究。本文主要综述了静电纺丝纳米纤维在食品科技领域的四方面主要应用:食品包装材料开发;食品快速检测技术开发;食品载体技术开发;食品添加剂开发,并从纳米纤维制备技术角度对每一个应用领域进行了亚类分类。本文将为静电纺丝纳米纤维用于食品科技领域提供总结与指导。      

Antimicrobial effectiveness of bioactive packaging materials from edible chitosan and casein polymers: assessment on carrot, cheese, and salami

Antimicrobial packaging is one of the most promising active packaging systems for controlling spoilage and pathogenic microorganisms. In this work, the intrinsic antimicrobial properties of chitosan (CH) were combined with the excellent thermoplastic and film-forming properties of sodium caseinate (SC) to prepare SC/CH film-forming solutions and films. The antimicrobial effectiveness of SC, CH, and SC/CH coatings on the native microfloras of cheese, salami, and carrots was evaluated. In vitro assays through the test tube assay indicated that the most significant antimicrobial effect was achieved by CH and SC/CH solutions on carrot and cheese native microfloras. SC film-forming solutions did not exert antimicrobial activity on any of the native microflora studied. SC, CH, and SC/CH films stored in controlled environments showed that the retention of the antimicrobial action was observed until 5-d storage, at 65% relative humidity in both temperatures (10 °C and 20 °C). In vivo assays were also performed with SC, CH, and SC/CH applied as coatings or wrappers on the 3 food substrates. CH and SC/CH applied at both immersion and wrapper exerted a significant bactericidal action on mesophilic, psychrotrophic, and yeasts and molds counts, showing the 3 microbial populations analyzed a significant reduction (2.0 to 4.5 log CFU/g). An improvement of the bactericidal properties of the CH/SC blend respect to those of the neat CH film is reported. The ionic interaction between both macromolecules enhances its antimicrobial properties. Practical Application: The continuous consumer interest in high quality and food safety, combined with environmental concerns has stimulated the development and study of biodegradable coatings that avoid the use of synthetic materials. Among them, edible coatings, obtained from generally recognized as safe (GRAS) materials, have the potential to reduce weight loss, respiration rate, and improve food appearance and integrity. They can be used in combination with other food preservation techniques in order to extend the effectiveness of the food preservation chain. Moreover, antimicrobial films and coatings have innovated the concept of active packaging and have been developed to reduce, inhibit, or delay the growth of microorganisms on the surface of food in contact with the package. The use of antimicrobials packaging films to control the growth of microorganisms in food can have a significant impact on shelf-life extension and food safety. In addition, antimicrobial films can be prepared by the combination of inherent antimicrobial materials (that is, CH), with good film-forming protein-based ones (that is, SC). Therefore, the objective of this work is to study the performance of 2 biodegradable and edible biopolymers and their combination as natural packages for selected food products.