Trends in Food Science & Technology 19 (2008) S103eS112

Review Active and intelligent

Introduction food packaging: legal New food packaging technologies are developing as a re- sponse to consumer demands or industrial production trends towards mildly preserved, fresh, tasty and convenient aspects and safety food products with prolonged shelf-life and controlled quality. In addition, changes in retailing practices (such as concerns market globalisation resulting in longer distribution of food), or consumers way of life (resulting in less time spent a shopping fresh food at the market and cooking), present Dario Dainelli , Nathalie major challenges to the food packaging industry and act Gontardb,*, Dimitrios as driving forces for the development of new and improved c packaging concepts that extend shelf-life while maintaining Spyropoulos , Esther and monitoring food safety and quality. d Traditional food packaging is meant for mechanical sup- Zondervan-van den Beuken and porting of otherwise non-solid food, and protecting food Paul Tobbacke from external influences, like microorganisms, oxygen, off-odours, light etc. and, by doing so, guaranteeing conve- aSealed Air Corp., Via Trento 7, I-20017 Passirana di nience in food handling and preserving the food quality for Rho, Milano, Italy an extended time period. The key safety objective for these bAgropolymers Engineering and Emerging traditional materials in contact with foods is to be as inert Technologies, UMR IATE CC023, Universite´ de as possible, i.e., there should be a minimum of interaction Montpellier II, Pl. E. Bataillon, F-34095 Montpellier between food and packaging. cedex, France (e-mail: [email protected]) In the last decades, however, one of the most innovative cEuropean Food Safety Authority (EFSA), Largo N. Palli developments in the area of food packaging is the ‘active 5/A, 43100 Parma, Italy and intelligent’ (A&I) packaging, based on deliberate inter- actions with the food or the food environment. dTNO Quality of Life, P. O. Box 360, 3700 AJ Zeist, The purpose of the ‘active packaging’ is the extension of The Netherlands the shelf-life of the food and the maintenance or even im- e Laboratory of Food Technology, Katholieke provement of its quality. While the purpose of ‘intelligent Universiteit Leuven, p/a Karrestraat 2, 3020 Herent, packaging’ is to give indication on, and to monitor, the Belgium freshness of the food. Due to its deliberate interaction with the food and/or its ‘Active and intelligent’ (A&I) food packaging is based on a de- environment A&I packaging poses new challenges to the liberate interaction of the packaging with the food and/or its evaluation of its safety as compared to the traditional pack- direct environment. This article presents: (i) the main types aging. However, also in this case the migration of sub- of materials developed for food contact; (ii) the global market stances from the packaging to food is the main risk. and the future trends of active and intelligent packaging with Other risks could occur from the incorrect use of the pack- a special emphasis on safety concerns and assessment; and aging due to the insufficient labelling or the non-efficacious (iii) the EU Legislation and compliance testing of these novel operation of the A&I packaging. The Regulation 1935/2004 food packaging technologies. on materials and articles intended to come into contact with food already contains general provisions on the safety of active and intelligent packaging and sets the framework for the EFSA’s safety evaluation process. A new Regulation specific to (A&I) packaging is expected to be published in 2009 with provisions dedicated * Corresponding author. to this type of packaging. The EFSA’s guidelines on the 0924-2244/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.tifs.2008.09.011 S104 D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 data to be provided for safety evaluation are currently under to leaves commercialization. Beyond their use as a simple preparation to help risk managers define lists of authorised ‘barrier’, numerous varied vegetal leaves are used for their substances. ability to transfer to foods, aromatic, coloring, enzyme Many scientific publications and reviews have been re- (e.g. papa€ın) or antimicrobial substances (e.g. essential cently devoted to research on active and intelligent food oils). Vegetal leave packaging interacts with foods for mod- packaging technologies (e.g. Ahvenainen, 2003; Brody, ifying their texture, organoleptic properties or slowing down Strupinsky, & Kline, 2001; Chiellini, 2008; Han, 2005; microbial spoilage. They are also used for their ability to Ozdemir & Floros, 2004; Wilson, 2007). The objective of change colour with temperature and/or time thus playing the present article is to give an overview of history, main the role of cooking or freshness indicators. Up to four differ- types and principles, global market and future trends, with ent types of leaves are used as successive layers, each of them a special emphasis on safety concerns, legal aspects and com- having a very specific function. Leaves have also been used pliance testing of these novel food packaging technologies. for ages in Mediterranean regions of Europe, e.g., to wrap tra- ditional cheeses for allowing good maturation process. Technological evolutions and safety evaluation of In developed countries, moisture and oxygen absorbers active and intelligent food packaging were among the first series of active and intelligent packag- Definitions and brief history ing to be developed and successfully applied for improving Innovations in packaging were up to now limited mainly food quality and shelf-life extension (e.g. for delicatessen, to a small number of commodity materials such as barrier cooked meats etc.) Next to these, numerous others concepts materials (new polymers, complex and multilayer mate- such as ethanol emitters (e.g. for bakery products), ethylene rials) with new designs, for marketing purposes. However, absorbers (e.g. for climacteric fruits), carbon dioxide emit- food packaging has no longer just a passive role in protect- ters/absorbers, time/temperature and oxygen indicators etc. ing and marketing a food product. New concepts of active have been developed (Fig. 1). In a general way, the field has and intelligent packaging are due to play an increasingly been extended largely as a series of niche markets owing to important role by offering numerous and innovative solu- the current approach of packaging industries looking at it in tions for extending the shelf-life or maintain, improve or terms of new market opportunities (Rooney, 2005). The ra- monitor food quality and safety (Gontard, 2006). Various tionale in considering a range of packaging options (both terms are used for describing new packaging technologies, passive and active) as a whole and as a part of the food e.g. ‘active’, ‘interactive’, ‘smart’, ‘clever’, ‘indicators’ etc technological itinerary has not yet been commonly adopted (Fabech et al., 2000; Gontard, 2000). (Gontard, 2006). Two definitions are now included in the new Framework If compared to Japan, USA or Australia, the penetration Regulation on Food Contact Materials (1935/2004). of active and intelligent packaging in the European market is limited thus far. This time lag compared to Japan, USA (i) ‘Active food contact materials and articles’ are defined and Australia was mainly attributed to an inadequate and as materials and articles that are intended to extend the not enough flexible European regulation that could not shelf-life or to maintain or improve the condition of keep up with technological innovations in the food packag- packaged foods. They contain deliberately incorpo- ing sector (Fig. 1). European legislation has been changed rated components intended to release or absorb sub- in 2004 with the new FCM Framework Regulation (1935/ stances into or from the packaged food or from the 2004) and this change will be soon achieved with a specific environment surrounding the food. Active materials regulation entirely devoted to active and intelligent food and articles are allowed to bring about changes in contact materials. But in addition, it should be mentioned the composition or the organoleptic characteristics that the issues of acceptance by user industries as well as of the food on condition that the changes comply the more conservative behaviour of European consumers with the provisions foreseen in the Community or regarding innovations in food, are key points that still national food legislations. need to be addressed in this field. Moreover, in some cases, (ii) ‘Intelligent food contact materials and articles’ are de- efficacy, safety and benefits need to be better demonstrated fined as materials and articles that monitor the condi- and weighted to increase the number of products launched tion of packaged food or the environment onto the European market. surrounding the food. Active packaging Paradoxically, whereas the concept of active and intelli- The principles behind active packaging are based either on gent packaging is now considered as ‘modern’, the concept the intrinsic properties of the polymer used as packaging ma- belongs to ancestral traditions in all tropical areas of the terial itself or on the introduction (inclusion, entrapment etc.) world. of specific substances inside the polymer (Gontard, 2000). In these regions of Africa, Asia and South America, veg- The intrinsic properties of the polymer can give rise to etal leaves were, and still are, profusely and traditionally the active function next to, e.g., the intentional grafting of used for food packaging with important markets dedicated an active group or through the introduction of an active D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 S105

Japan

CO2 absorber/emitters Antimicrobial packaging

Ethylen absorber USA Pathogen indicator

Self-cooling or self- Leak indicator heating packaging EU Time-temperature SO2 emitter indicators

Oxygen absorber

Moisture absorber

Legislation

The roots: traditional vegetal leaves in tropical area of Africa, Asia and South America

Fig. 1. Active packaging tree: the roots in active vegetal leaves of tropical countries, example of the main active packaging materials marketed in developed countries and main countries where these materials were developed (N. Gontard pictures). monomer inside the polymer chain. An active agent can be food. The most well known examples of non-migratory ac- incorporated inside the packaging material or onto its sur- tive packaging are moisture absorbers, mostly based on the face, in multilayer structures or in particular elements asso- adsorption of water by a zeolite, cellulose and their deriv- ciated with the packaging such as sachets, labels or bottle atives etc. The tendency in the market of moisture ab- caps. sorbers systems is to introduce the absorbing substances The nature of the active agents that can be added is very inside the packaging material in order to make the active diverse (organic acids, enzymes, bacteriocins, fungicides, system invisible for the consumer such as, e.g., absorbing natural extracts, ions, ethanol etc.) as well as the nature trays for fresh meat or fish. of the materials into which they are included such as Other well known active packaging systems are oxygen papers, plastics, metals or combinations of these materials. absorbers, mostly based on iron oxidation but they can also The active systems can be placed outside the primary be based on ascorbic acid or catechol oxidation, on packaging, in between different parts of the primary pack- enzymatic catalysis as well as on many other reactions. aging or inside the primary packaging. In this last case, the The development of oxygen scavenging systems was first systems can be in contact only with the atmosphere based on self-adhesive labels, others adhesive devices or surrounding the food, in contact with the food surface or loose sachets to be included in the packaging with the placed inside the food itself (for liquid foods). This diver- food. A second concept, developed later, was based on sity accounts for the innovation potential in this field but the design of active substances for being included in the it also represents a real challenge for the safety assessment. packaging material itself, using monolayer or multilayer Active packaging can be classified into two main types: materials or reactive closures liners for bottles and jars non-migratory active packaging acting without intentional (Rooney, 2005). Ethylene scavengers, based on various re- migration, and active releasing packaging allowing a con- actions, are extensively used to slow down the maturation trolled migration of non-volatile agents or an emission of rate of climacteric fruits, a crucial point for import-export volatile compounds in the atmosphere surrounding the of fresh fruits and vegetables. Another example of non-mi- food (Fig. 2). gratory packaging is the antimicrobial packaging based on Non-migratory active packaging is a packaging which the entrapment in a silicate network of silver ions, a widely elicits a desirable response from food systems without the marketed antimicrobial agent. Nevertheless, even food con- active component migrating from the packaging into the tact antimicrobial systems with an assumed non-intended S106 D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112

Non Migratory Active FCM: - Effect without intentional migration (covalent grafting or immobilisation of active functions)

Active Releasing FCM: - contact effect for controlled migration of non- volatile active agents

- controlled/ triggered emission of active volatile compounds into headspace atmosphere surrounding food

Fig. 2. Scheme of the two different types of active food contact materials (FCM) classified as a function of intentional or unintentional migrations. migration (e.g. silver or silver based systems, other immo- Another example of active releasing materials is a plastic bilised or grafted biocides), are known to exhibit some film commercially available in Japan, containing allyl degree of migration. Thus, there is a strong need to better isothiocyanate (AITC), a strong antimicrobial substance understand the active agent principles and mechanisms as extracted from mustard or wasabi. AITC is entrapped in well as to optimise their use in order to design active pack- cyclodextrins for protecting the volatile active agent from aging elements that (i) are sufficiently effective and reduce being thermally degraded during extrusion. When exposed detrimental side effects and (ii) permit an accurate, knowl- to high moisture conditions after the packaging of the food edge-based, assessment of potential risks. It is clear from product, cyclodextrins have the ability to change in struc- the existing literature in the challenging field of antimicro- ture and to release the antimicrobial agent in the atmo- bial packaging that research results on antimicrobial sys- sphere surrounding the food (Lee, 2005). tems are often not reproducible or even contradictory, Research in the area of antimicrobial food packaging i.e. the case of chitosan or chitosan-based systems of which materials has significantly increased during recent few biocide phenomenology and the optimum efficiency have years as an alternative method for controlling microbial just recently been understood on the basis of the positive contamination of foods by the incorporation of antimicro- migration of glucosamine fractions (Fernandez-Saiz, bial substances in or coated onto the packaging materials Ocio, & Lagaron, 2006) and related to food composition (Benarfa, Presiozi-Belloy, Chalier, & Gontard, 2007). (Fernandes et al., 2008). It should be mentioned that an Much research is devoted to the design of antimicrobial extensive research is underway on in-package enzymatic packaging containing natural volatile antimicrobial agents processing and non-migratory antimicrobial packaging, for specific or broad microbial inhibition depending on including the grafting of active agents onto the polymer sur- the nature of the agents used or on their concentration. Dif- face (Goddard, Talbert, & Hotchkiss, 2007). These agents ferent types of antimicrobial delivery systems and packag- can be, e.g., antimicrobials, antioxidants or enzymes that ing materialefood combinations are developed to can act either on the surface of a solid food or in the maximize the efficacy of the system (Gontard, 2007). bulk of liquid foods. In active packaging, nanotechnology has a great interesting In the field of active releasing packaging, one of the potential because nanostructures display a high surface-to- best-known products is an ethanol releaser which is able volume ratio and specific surface properties. Nanotechnol- to slow down mould growth and thus increasing the ogies such as nano(bio)composites and electro spun shelf-life of bakery products. Water-vapour releasing sa- nano-fibre based structures are able to enhance desired prop- chets are a key element of successful innovative packaging erties or to introduce new additional effective functionalities for ready-to-cook fresh vegetables. Combined with a valve with small amount of nanofillers (Lagaron, Cava, Cabedo, placed onto the plastic pouch, they permit to cook fresh Gavara, & Gimenez, 2005). Recent studies also show that vegetables in a microwave oven and to obtain, in only nano-particles can be tailored for both controlled release a few minutes, a freshly cooked meal with improved organ- and/or specificity in the action of the active agent having mois- oleptic and nutritional quality. ture or temperature as triggering mechanisms (second gener- Sulphur dioxide releaser packaging is extensively used ation of nano-structured materials). for preserving grapes from mould development. Some com- As for any other new technology that is coming into the mercial products are based on the reaction of calcium stage of application, a sound evaluation and a risk-benefit sulphite with moisture, while others are based on metabi- analysis needs to be carried out. In this context, nanostruc- sulphite hydrolysis. In these cases, one of the breakdown tures are generated by one- or two dimensional nano-addi- products, originating from the reaction with moisture, is tives being the other dimension more in the conventional the active agent. micro size, thus resulting in a reduced potential mobility. D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 S107

Therefore, these nano-carriers can be considered of less toxins as well as pathogenic bacteria themselves. Commer- safety concern than other nano-particles. On the other cially available direct indicators are, e.g., a pear maturation hand, the high surface developed by nano-particles can po- indicator based on the detection of a volatile aroma com- tentially bind unwanted substances that could be otherwise pound or a fish freshness indicator based on the detection released in contact with foods. The full understanding of of volatile amines. More sophisticated systems are based the effect on food safety of the introduction of nanostruc- on depositing, on the bar code, a plastic layer loaded with tures has still to be ascertained. specific antibodies of pathogenic microorganisms such as salmonella or listeria whose presence can be detected when the bar code is read. Intelligent packaging Despite active research in the area, the application of in- Intelligent packaging systems attached as labels, incor- telligent systems in Europe has mainly been limited to the porated into, or printed onto a food packaging material use of visual temperature or timeetemperature indicators. offer enhanced possibilities to monitor product quality, Reasons for this may have been the too high cost of an trace the critical points, and give more detailed information indicator label, legislative restrictions and even acceptance throughout the supply chain (Han, Ho, & Rodrigues, 2005). of retailers and brand owners. The fear could be that indi- Intelligent tags such as electronic labelling, designed with cators would reveal possible irregularities occurring, e.g., ink technology in a printed circuit and built-in battery ra- in the management or control of the cold chain. On the dio-frequency identity tags, all placed outside the primary other hand, a few shortcomings of these indicators also packaging, are being developed in order to increase the exist, e.g. their response to oscillating temperature patterns efficiency of the flow of information and to offer innovative (Malcata, 1990). Safety issues come mainly from direct communicative functions. Diagnostic indicators were first indicators that are required to be placed inside the primary designed to provide information on the food storage condi- packaging for direct contact with the atmosphere surround- tions, such as temperature, time, oxygen or carbon dioxide ing the food or with the food itself, because of potential content, and thus, indirectly, information on food quality, as undesirable migration of chemical components. an interesting complement to end-use dates for example (Fig. 3). Based on polymerisation rate, diffusion, chemical or en- Future trends and safety issues zymatic reactions, the most commonly used of these visual Research and development in the field of active and in- indicators are critical temperature indicators, time/tempera- telligent packaging materials is very dynamic and develops ture indicators and leak indicators. This first generation of in relation with the search for environment friendly packag- indicators can be considered as ‘‘indirect indicators’’ of ing solutions. In this context, the design of tailor-made food freshness. The trend in this field is to develop direct packaging is a real challenge and will imply the use of indicators of food quality because of their ability to provide reverse engineering approach based on food requirements more precise and targeted information on quality attributes and not anymore only on the availability of packaging (Gontard, 2004). Targeted quality markers can be volatile materials. Nanotechnologies are expected to play a major compounds (e.g. volatiles of microbial origin) such as car- role here, taking into account all additional safety consider- bon dioxide, nitrogen compounds etc. or biogenic amines, ations and filling the presently existing gap in knowledge.

FOOD QUALITY

INDIRECT INDICATORS DIRECT INDICATORS

Volatile compounds: organic acids (pH), Storage conditions: Microbial growth and ethanol, T¡, time, O2, CO2É spoilage - Food quality CO2, nitrogen compounds, sulfuric compounds Critical temperature indicators (SH2) etc. Time -Temperature Pathogenic indicators bacteria Biogenic amines Leak indicators ATP degradation Aroma products compounds Toxins etc.

Fig. 3. Food quality indicators: main indirect indicators and trend towards direct indicators of microbial growth and spoilage and others food qualities attribute. S108 D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112

They will be involved in the development of triggered/con- Packaging (MAP), considered as an ideal field for oxygen trolled release of active agents and for targeted indicators. absorbing packaging applications. New non-migratory materials for innovative functions The 1.4 M US$ value of the market in 2002 was fore- such as in-package food processing are also a promising seen to attain a value between 2.6 and 3.7 M US$ in field of development. 2007 thanks to the development of the bottled bier and fruit In a general way, the answer to safety issues in relation juices market, as well as the development of MAP for fresh with active and intelligent packaging should be based on meat, ready meals, fresh pasta etc. Oxygen scavengers were three main pillars: then believed to reach sales as high as 5.7 billion units in Europe in 2007 (versus 0.3 billion in 2001) and 4.5 billion (1) labelling, with the aim to prevent misuse and misunder- units in the USA in the same year (versus 0.5 billion in standing by the downstream users or consumers, e.g. to 2001). Although price was already considered one of the avoid sachets from being ingested; main limiting factors, in 2002 almost 80% of the industry (2) migration of active and intelligent substances should be was convinced that the technical progress would have carefully considered as well as all breakdown products, decreased it to an affordable level within 2005. as function of their toxicity. The compliance of releas- In fact, these optimistic forecasts have only partially ing active packaging with food legislation shall be been achieved: both Europe and the USA did not fully closely related to migration phenomena. Assessing match the expected growth, while Japan showed a steady migration implies to develop dedicated migration tests market increase in line with the previous years. Although as well as mass transfer modeling tools because those not boosted, the market of centrally food packed in MAP existing, or recommended for conventional plastics, did show an increase. But, in reality, food industries have are not adapted to active and intelligent systems; been somewhat reluctant to invest in active packaging (3) efficacy of the packaging: finally, in some very specific concepts. cases, the ability of the packaging to perform the There are two main reasons that would explain such be- claimed function can raise safety issues as for any haviour. The first is related to cost: being highly specialised food preservation technology, e.g. delivering a preserva- and containing often sophisticated technologies, active and tive or absorbing oxygen in a suitable way for prevent- intelligent materials still account for 50e100% of the ing microbial growth without inducing antimicrobial whole packaging cost. This is simply not affordable by resistance or pathogen over growth, or giving reliable most of the food industries, where packaging cost can information on pathogenic bacteria presence for direct hardly exceed 10% of the total cost of items placed on indicators. the market, and where special packaging performances may be desired provided that they are supplied at commod- A flexible legislative framework and appropriate testing ity price (this may be less critical for other markets like methods are required for supporting such a highly innova- medical packaging where the packaging cost is proportion- tive field, i.e. to keep up not only with the market as it is, ally less important). The second reason is acceptance: often but also as it will be. consumers do not perceive active and intelligent materials as a strong benefit. Consumers’ attitude is often driven by Evaluation of the global market of active and the idea that food with shorter shelf-life is fresher and a con- intelligent packaging cept like oxygen scavengers that would extend the shelf-life Active and intelligent packaging materials and articles may not be seen attractive, although convenient in certain were firstly introduced in the market of Japan in the mid situations but at the detriment of freshness. Also, time/tem- 70s, but only in the mid 90s they raised the attention of perature indicators that provide quite accurate information the industry in Europe and in the USA. In this period, there about the real freshness of the food, or whether the food un- was a proliferation of patents and market tests that created derwent stressing temperature conditions may not be seen great expectations of commercial growth. by retailers as a valid sales incentive as they would likely In 2002, the global market accounted for about 1.4 M induce consumers to choose only newly displayed items US$, more than 80% of which was represented by two spe- and would increase the amount of unsold foodstuffs. cific active concepts, namely oxygen scavengers and mois- In a study carried out by PIRA International, both brand ture absorbers (40% each), the main application being in owners and packaging converters identified as main resis- areas like optical devices, electronic tools, medical and tance to the introduction of these materials in the market pharmaceutical preparations and others. Packaging, in par- the fact that the existing materials were considered already ticular food packaging, represented a very small fraction of adequate to the market needs (Table 1)(Anonymous, 2006). the market in these years and it was almost totally concen- As already outlined, price was also seen as a strong lim- trated in Japan. However, the food packaging sector was iting factor and overall the lack of perceived consumers’ identified as the most fast growing market; that belief demand did result into a negative cost/benefit analysis. was caused by strong expectations of growth of centrally On the other hand, the perspective of the companies provid- prepared perishable foods in Modified Atmosphere ing the technology leading to these materials was rather D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 S109

Table 1. Importance ranking of factors restricting the adoption of scavengers. Table 2 shows the market value of the main ac- active and intelligent packaging according to brand owners, pack- tive packaging concepts in 2001 and 2005, together with aging converters and technology providers (Anonymous, 2006). the forecast for 2010 (Anonymous, 2007). Resistance to introduction of Brand Packaging Technology Besides the interesting result of susceptors and self-vent- A&I packaging owners converters providers ing (450 M US$ in 2005), the numbers of antibacterial Existing packaging 11 8 films are worth noting. Antibacterial films may find appli- more than adequate cation in the food area, but their market remains almost Price 2 5 5 totally confined in Japan. They represent an example of No perceived demand 3 3 11 the heavy influence that regulatory issues may exert over Cost/benefit analysis 4 4 12 the market of these materials: use of antibacterial films in Unwilling to pay premium 5 2 10 Incompatible existing 65 8 food packaging has been always put in relation with relaxed pack techniques hygiene measures, which may be then compensated by the Lengthy regulatory 77 5 released antibacterial, therefore, perceived as a tool hinder- approvals process ing adoption of HACCP by food industries. As a result, no Consumer concerns 8 10 4 market exists for antimicrobial films in food packaging. Ineffective technology 8 12 1 Safety concerns 10 7 12 However, not all active and intelligent packaging con- Unproven technology 11 11 2 cepts show just steady market behaviour: there is at least Legislative concerns 12 7 2 one system the trend of which boosted in the last five years, Opposition from retailers 13 12 5 and that is Radio-Frequency Indicators (RFID). However, it is questionable whether RFID can be classified as active or different. They identified as main limiting factor the often- intelligent food packaging materials, as they do not pre- questionable efficiency of active and intelligent materials. cisely match the definition of ‘‘interacting with food or In fact, in most of the numerous patents filed during the with the atmosphere to which food is exposed, or giving in- course of the years active and intelligent concepts were formation on the conditions to which food is or has been demonstrated to perform efficiently almost always in exposed’’. in-vitro essays and under laboratory tests conditions. How- ever, when used in real food packaging applications, they Legislation and compliance testing of active and either showed a more limited activity or no activity at all. intelligent food packaging The rationale of such behaviour lies in the often very differ- Legislation ent conditions between model tests and real food, e.g. dif- Framework Regulation ferent quantity of foodstuffs packed, ratio and distribution To be on the European market, each system should com- of fat and non-fat parts, fluctuation and variability of phys- ply with the legislation. As regards the non-active part, e.g. ical and chemical parameters such as water activity, pH etc. the packaging of the active constituents, it should comply Another concern, which is perceived as a threat by technol- with the applicable food contact legislation (Fig. 1). This ogy providers, is the lack of a clear regulatory picture, lead- is the Framework Regulation (EC) 1935/2004 for all food ing to a certain degree of reluctance from food packers to contact materials. Under this regulation, there are some adopt concepts that are not fully covered by the food specific Directives, e.g. the plastic Directive 2002/72/EC. contact materials legislation. A partial answer to such a con- All food contact materials made of plastic are subjected cern has been given by the European Commission through to this Directive. However, many active and intelligent the Regulation 1935/2004/EC, although this may still be packaging systems are composed of different materials open to interpretation. Finally, in the last few years the reduction of environ- mental impact of food production and distribution (the Table 2. Global market value (million US $) of active and intelli- so-called ‘‘carbon footprint’’ concept applied to food indus- gent packaging (Anonymous, 2007). try) comes more and more into focus due to environmental Type of A&I system 2001 2005 2010 Market and economic concerns, the latter being associated with the (Forecast) share (%) strong recorded increase of oil price. As a result, supermar- Oxygen scavengers 371 660 985 37 kets and retailers should try to source food more and more CO2 scavengers/emitters 81 108 156 6 locally, at the detriment of packaging materials devoted to Ethylene scavengers 30 57 100 3 Moisture scavengers 190 287 405 16 long haul transport of food. Ethanol emitters 21 37 65 2 On the other hand, the reduced time spent in food prep- Flavour/adour absorbers 28 47 70 3 aration gave some impulse to packaging concepts that are Antioxidants 3 7 20 0 associated to ready meals and use of microwave ovens, self-venting 195 280 550 16 such as susceptor laminates and self-venting trays. Susceptor laminates 80 165 265 9 Temperature control 15 38 100 2 In fact, the global value of the market in 2005 was about 1.8 M US$, 40% being still represented by oxygen Total 1064 1786 2556 100 S110 D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 and are excluded from the Directive 2002/72/EC. These - substances that are released from active packagings materials have to comply with the national legislation shall be authorised and used in accordance with the which is present in some countries, e.g. Germany and relevant community provisions applicable to food; The Netherlands. Under the principle of mutual recogni- - active materials shall not bring about changes in the tion, other countries should accept food contact materials composition or organoleptic characteristics of the produced in these countries provided such country has no food, for instance by masking the spoilage of food, specific regulation in the relevant fields (Fig. 4). which could mislead the consumer; For the active/intelligent component in active and intel- - intelligent materials shall not give information about ligent packaging, there is no specific Directive or regulation the condition of the food which could mislead the at this moment and they have to comply with the Frame- consumer; work Regulation (EC) 1935/2004. Important articles are - adequate labelling to allow identification of non-edible Articles 3 and 4. Article 3 is applicable to the packaging parts; of the active or intelligent components. The active and - adequate labelling to indicate that the materials are intelligent components are subject to Article 4. active and/or intelligent. Article 3 of the Framework Regulation states that food contact materials shall not transfer constituents to food in Finally, Article 15 of the Framework Regulation states quantities which could: that the consumer and the food packer must be informed on how to use the active and intelligent materials and - endanger human health; articles safely and appropriate. - bring about an unacceptable change in the composition; - bring about deterioration in organoleptic characteristics thereof. Draft regulation on active and intelligent packaging materials Furthermore, labelling, advertising and presentation of In addition to the Framework Regulation, there is a spe- the material or article should not mislead the consumer. cific Regulation in preparation for the active and intelli- Article 4 of the Framework Regulation describes special gent packaging. However, it should be noted that this requirements for active and intelligent materials in which Regulation is under discussion at the moment and the the main issues are: items described below are based on our personal view based on literature (Actipak, 2001; van Dongen, de Jong, - active materials may bring about changes in the compo- & Rijk, 2007, chap. 9; van Dongen & de Kruijf, 2007, sition or organoleptic characteristics of food on the con- chap. 17). dition that the changes comply with the community or One of the major issues in this draft Regulation is that national provisions applicable to food; the active and intelligent substances require authorisation.

Framework Regulation (EC) 1935/2004

Specific Directives Special Directives Plastics 2002/72/EC* Basic rules for migration testing Ceramics 84/500/EEC* Test conditions 82/711/EEC* Cellophane 93/10/EC* Simulant selection 85/572/EEC* Nitrosamines 93/11/EC Vinylchloride 78/142/EC*

* means amendments are connected d

Specific regulations Epoxy comp. 1895/2005 Implemented in National GMP 2023/2006 Legislation Gaskets 372/2007 Draft A&I packaging

Fig. 4. Food contact material legislation in EU. D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 S111

For authorisation, a petition should be prepared of the may be in contact with dry foods, e.g. coffee, bakery ware, active/intelligent substance in a similar way as is required fruits or with liquid foods, e.g. beer, beverages, or with for plastics. A guidance document to compile the petition (semi) solid foods, e.g. meat, fish, nuts. In case of dry dossier is in preparation. foods, specific migration of substances should be measured Other items that will likely be included in the draft Reg- directly in the food, as there are no tests prescribed with ulation are: simulants. Contact with liquid foods should be tested according to the Directives 82/711/EEC and 85/572/EEC. - the released substance is excluded from the overall In these cases, there are no reasons to deviate from the con- migration; ventional rules. Only in case of (semi) solid foods, there - food shall comply with food regulation; may be problems that need special requirements and testing - the active/intelligent packaging should be suitable and protocols. New dedicated test protocols should be used for effective for the intended purpose; this purpose described by Actipak (2001) and Lopez- - materials that may be mistaken as a part of the food Cervantes, Sanchez-Machado, Pastorelli, Rijk, and (e.g. loose sachets) must be labelled using the symbol Paseiro-Losada (2003). for the non-edible part (Fig. 5); An example is an oxygen scavenger containing iron used - the declaration of compliance and supporting for a meat product. Using the conventional test according to documentation. Directives 82/711/EEC and 85/572/EEC for the determina- tion of the overall or specific migration, the oxygen scaven- Compliance testing ger should be immersed in water or 3% acetic acid and Directives (82/711/EEC or 85/572/EEC) set require- stored for the prescribed timeetemperature conditions. ments for testing the migration from food contact materials. However, this is an unrealistic situation in case the oxygen Not all active and intelligent packaging systems can be scavenger is used for a meat product. For this purpose, tested according to these Directives. Distinction should be a dedicated test is developed to perform an overall migra- made between systems inside or outside the primary pack- tion with filter paper soaked with simulant (Fig. 2). In aging. Systems outside the packaging need in general no this test, samples are wrapped with the filter paper which migration testing as there will be a ‘‘functional barrier’’ is saturated with simulant and placed between glass plates. which reduces the potential migration significantly. In addi- To simulate the possible weight of food a total weight of tion, most intelligent systems attached on the outside of the 70 g (including the glass plate of 20 g) is placed on top packaged food concerns foods stored for a relatively short of the package (see Fig. 6). The whole package including period at lower temperatures. The risk of exceeding a lag- weight is placed in the oven and stored for the correct time in diffusion is negligible. Nevertheless, there should time/temperature conditions. After the storage period the be a judgement on a case by case basis. filter paper are extracted with the food simulant to deter- Active and some intelligent systems are always in ‘‘di- mine the overall or specific migration. rect’’ contact with food. If the active or intelligent ingredi- Comparison of the dedicated test with the conventional ent is incorporated in the plastic film, then such a material test according to Directives 82/711/EEC and 85/572/EEC shall comply with the conventional rules laid down in the showed much lower and more realistic overall migration EU Directives. Both positive list and migration behaviour for the dedicated test compared to the conventional test. should be in compliance because the way of contact as In conclusion, active and intelligent packaging systems well as the surface-to-volume ratio is equal to the normal should comply with the Framework Regulation (EC) packaging materials. 1935/2004. Main requirements in this Framework Regula- In other cases, the active or intelligent system is inserted tion are that active materials may bring about changes in in the primary packaging in the form of a box, sachet, label the composition or organoleptic characteristics of food on or sheet, containing the typical active ingredients. Gener- ally, the ratio of food to contact area is large and the contact is not very intense. To establish the requirements of such systems, the type and physical state of the food in contact 50 g with the systems should be taken into account. The system Glass plate 20 g

Filter paper with simulant

Oxygen absorbing label

Glass plate

Fig. 5. Symbol for ‘non-edible’ parts in FCM labelling. Fig. 6. Layout for dedicated migration test for oxygen absorbing label. S112 D. Dainelli et al. / Trends in Food Science & Technology 19 (2008) S103eS112 the condition that comply with the Community provisions Fernandes, J., Tavaria, F., Soares, J., Ramos, O., Monteiro, M., applicable to food. Substances are allowed to be released Pintado, M., et al. (2008). Antimicrobial effects of chitosans provided that the food is in accordance with the Food and chitooligosaccharides, upon Staphylococcus aureus and Escherichia coli, in food model systems. Food Microbiology, Law. Furthermore, active materials and intelligent packag- 25, 922e928. ing should not mislead the consumer for instance by mask- Fernandez-Saiz, P., Ocio, M. J., & Lagaron, J. M. (2006). Film-forming ing the spoilage of food or by giving incorrect information. process and biocide assessment of high-molecular-weight chitosan Finally, adequate labelling is needed. 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