Trends in Food Science & Technology 22 (2011) 611e617

* Corresponding author.

0924-2244/$ - see front matter � 2011 Elsevier Ltd. All rights reserved.doi:10.1016/j.tifs.2011.01.007

Nanotechnology for

bioplastics:

opportunities,

challenges and

strategies

Jose M. Lagaron* and

Amparo Lopez-Rubio

Novel Materials and Nanotechnology Group,

IATA, CSIC, Avda. Agust�ın Escardino 7,

46980 Paterna, Valencia, Spain

(Tel.: D34 963 900 022; fax: D34 963 636 301;

e-mail: lagaron@iata.csic.es)

Recent years have witnessed a tremendous expansion of

research and technology developments in the nanotechnology

field resulting in significant application developments in the

food and agricultural areas. This is particularly the case of

the food packaging field, where significant advances in the

nanoreinforcement of biobased materials provide a more solid

ground towards increasing the technical and economical

competitiveness of renewable polymers for different applica-

tions. However, there is still a long way to go, not only in

the materials development and energy consumption minimi-

zation parcels, but also regarding the widespread commercial-

ization of these novel nanostructured biopolymers and the full

characterization of any particular potential toxicological and

environmental impacts. In this paper, the current situation of

these novel nanobiostructured packaging materials is

described, together with the global challenges to be faced

and the possible strategies to overcome some of the pending

issues in this exciting and potentially world changing research

and development area.

IntroductionIn the last decades there has been a significant increase in

the amount of plastics being used in various sectors, partic-ularly in food packaging applications. In fact, the largest ap-plication for plastics today is packaging, and within thepackaging niche, food packaging amounts as the largest plas-tics demanding application (Lagaron&Lopez-Rubio, 2010).This is so, because plastics bring in enormous advantages,such as thermosealability, flexibility in thermal and mechan-ical properties, permit integrated processes (i.e. plastic pack-ages can be formed, filled and sealed in a continuous mannerwithin the production line), lightness and low price. How-ever, polymers do also have a number of limitations for cer-tain applications when compared with more traditionalmaterials like metals and alloys or ceramics. The chief lim-itation being their inherent permeability to the transport oflow molecular weight components which leads to issuessuch as food oxidation by penetration of oxygen, migrationof toxic elements from the plastic and scalping of food com-ponents on the packaging with the consequent losses in foodquality and safety attributes. Among these, the potentialmigration beyond the legal limits of polymer constituentsand additives is perhaps the most widely recognized issueregarding packaged food safety. In spite of this, plasticmaterials continue to expand and replace the conventionaluse of paperboard, tinplated steel cans and glass which, inthe case of the latter two materials, have been typicallyused as monolayer systems in food applications. Initially,most plastic packagings were made of monolayer semi-rigidor flexible materials but, as the advantages of plasticpackaging became more established and developed, theincreasingly demanding food product requirements led, inconjunction with significant advances in plastic processingtechnologies, to more and more complex polymeric packag-ing formulations. This resulted in complex multicomponentstructures such as the so-called multilayer packaging-basedsystems widely used today, which in many cases can makeuse of metalized layers. Still, there are significant advantagesin terms of costs, ecopackaging strategies (that consists inreducing packaging materials consumption per packageunit) and other issues such as ease of recycling in developingsimpler, less environmentally concerned packaging formula-tions. As a result, strong efforts inmaterials development andin blending strategies have been carried out over the lastdecades to reduce complexity in food packaging structureswhile tailoring performance.

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Although packaging can help reduce organic waste bypreserving foods, the substantial increase in the use of plas-tics has also raised a number of environmental concerns fromawastemanagement point of view. As a result, there has beena strong research interest, pushed by authorities at nationaland international levels, and a concomitant industrial grow-ing activity in the development and use of biodegradableand/or biobased materials. The term “biodegradable” refersto materials that can disintegrate or break down naturallyinto biogases and biomass (mostly carbon dioxide and water)as a result of being exposed to a microbial environment andhumidity, such as the ones found in soil, hence reducing plas-tic waste, whereas “biobased” sustainable materials, apartfrom being typically biodegradable albeit not necessarily,consume carbon dioxide during their production, hence cre-ating the potential for the new concept of “carbon neutral ma-terials” (Haugaard et al., 2001; Lagaron, Gimenez, &Sanchez-Garcia, 2008; Petersen et al., 1999).

Amongst biobased materials, three families are usuallyconsidered: Polymers directly extracted from biomass,such as the polysaccharides chitosan, starch, carrageenanand cellulose; proteins such as gluten, soy and zein; and var-ious lipids. A second family makes use of biomass-derivedmonomers but uses classical chemical synthetic routes toobtain the final biodegradable and/or renewable polymers,including thermoplastics and thermosets such as thoseobtained derived from vegetable oils. In regard to thermo-plastics, this is the case of polylactic acid (PLA) and thenon-biodegradable sugar cane ethanol-derived biopolyethy-lene (Haugaard et al., 2001; Lagaron et al., 2008; Petersenet al., 1999). The third family makes use of polymers pro-duced by natural or genetically modified micro-organismssuch as polyhydroxyalkanoates (PHA) and polypeptidessuch as the elastin-like polymers (Reguera et al., 2003).Amongst non-biobased materials, i.e. using either petro-leum-based monomers or mixtures of biobased- and petro-leum-based monomers, there are also a number ofbiodegradable resins such as polycaprolactones (PCL), poly-vinyl-alcohol (PVOH) and its copolymers with ethylene(EVOH) and some biopolyesters. Nevertheless, it seemsclear that although biodegradability can help reduce plasticwaste, from a “green house” perspective, biobased sustain-able materials, the so-called bioplastics, are currently con-sidered the way to go and may be the only alternative inthe future as fossil resources become exhausted.

Moreover, in order to reduce energy consumption duringthe production of bioplastics and potential competition withagricultural resources for foods and also to provideadditional raw material sources, the exploitation of foodby-products is also the current trend. Food processing efflu-ents or solid wastes are only partially exploited and aremostly disposed in landfill sites where, since they are ame-nable to putrefaction, they have to be treated according tothe restrictions identified by, for instance, the internationalLandfill Directive (Awarenet, 2004). These by-productshave rarely been used as a source of high added-value

components such as food ingredients, but they present greatpotential value for their use in the production of bioplastics(Beccari et al., 2009).

In spite of the significant potential of bioplastics tosubstitute petroleum-based materials to help reduce envi-ronmental impacts, these materials still present a numberof property and processing shortcomings that precludetheir use in many applications, particularly in the foodpackaging field. The reasons for this are generally relatedto their lower barrier properties to gases and vapours,their strong water sensitivity, lower thermal resistance,lower shelf-life stability due to ageing, migration anda number of processability issues still associated to theuse of bioplastics (Haugaard et al., 2001). In this context,nanotechnology brings in significant opportunities tominimize the latter drawbacks. The main aim of the pres-ent paper is to give an overview of the main existingnanotechnologies for food biopackaging applications, de-scribing their current situation. Furthermore, the chal-lenges and possible strategies needed to developimproved and commercially viable biobased nanocompo-sites are also exposed.

Nanotechnology for packaging applicationsNanotechnology, by definition, is the creation and subse-

quent utilization of structures with at least one dimension inthe nanometre length scale (i.e. less than 100 nm) that cre-ates novel properties and phenomena otherwise not dis-played by either isolated molecules or bulk materials(Shonaike & Advani, 2003). Since Toyota researchers inthe late 1980s found that mechanical, thermal and barrierproperties of nylonenanoclay composite material improveddramatically by reinforcing with less than 5% of nanoclay,extensive research work has been performed in the study ofnanocomposites for food packaging applications (Okada,Kawasumi, Kurauchi, & Kamigaito, 1987). The term nano-composite refers to composite materials containing typi-cally low additions of some kind of nanoparticles.Specifically in the food biopackaging sector, nanocompo-sites usually refer to materials containing, typically,1e7 wt.-%, of modified nanoclays (Lagaron et al., 2005).For reinforcing purposes, a good interaction between ma-trix and filler is highly desired, which is often one of themajor challenges faced when developing new nanocompo-site materials. It has been observed that the interactions ma-trixefiller significantly improve when reducing the size ofthe reinforcing agent, always considering that both phasesare compatible and that the filler is properly dispersed(de Azeredo, 2009). Macroscopic reinforcing componentsusually contain defects, which become less important asthe particles of the reinforcing component are smaller(Ludue~na, Alvarez, & Vasquez, 2007). Therefore, shiftingfrom micro- to nanosized particles incorporated into thepolymeric matrices leads to better performance of the com-posite materials, although it can also lead to increased ag-glomeration of the filler particles.

0.00E+00

5.00E-19

1.00E-18

1.50E-18

2.00E-18

2.50E-18

P O

2 (m

3 m

/m

2 s P

a)

PHB

PHB-Nanocomposite

PLA

PLA-Nanocomposite

PET

PET-Nanocomposite

Fig. 1. Oxygen permeability of PLA, PHB and PET and of their nano-composites (Sanchez-Garcia et al., 2007).

613J.M. Lagaron, A. Lopez-Rubio / Trends in Food Science & Technology 22 (2011) 611e617

Moreover, the high surface-to-volume ratio of manynanoscale structures which favours this improved perfor-mance of composite materials, also becomes ideal for appli-cations that involve chemical reactions and drug delivery.Examples of their usefulness include the controlled and/orburst release of substances in active and functional foodpackaging technologies and energy storage applications in,for instance, intelligent food packaging (Lopez-Rubio,Gavara, & Lagaron, 2006; Shonaike & Advani, 2003).

NanoclaysAmongst the various existing nanotechnologies available,

the one that has attracted more attention in the bioplasticsfield is the nanoclay-based nanocomposites. It has beenbroadly reported in the scientific literature that the additionof low loadings of nanolayered clay particles, i.e. nanoclays,with thickness in the nanometre scale and with high aspectratios, to biopolymers can have a profound enhancing effectover somematerial properties, such as mechanical properties,thermal stability, UVevis protection, conductivity, process-ability and gas and vapour barrier properties (Cabedo,Gim�enez, Lagaron, Gavara, & Saura, 2004; Cyras,Manfredi, Ton-That, & V�azquez, 2008; Lagaron et al.,2005, 2008; Park, Lee, Park, Cho, & Ha, 2003; Petersson &Oksman, 2006; Sanchez-Garcia, Hilliou, & Lagaron, 2010;Xu, Ren, & Hanna, 2006; Yu, Lin, Yeh, & Lin, 2003). More-over, the addition of low amounts of nanoadditives does notalter to a significant extent, inherently good properties ofpolymeric matrixes such as transparency and flexibility(Marras, Kladi, Tsivintzelis, Zuburtikudis, & Panayiotou,2008; Sanchez-Garcia, Hilliou, et al., 2010; Sanchez-Garcia, Lagaron, & Hoa, 2010; Wan, Qiao, Zhang, &Zhang, 2003). Important issues associated to the use of bio-plastics, such as the non-intendedmigration of plastic compo-nents to foods, can also be potentially reduced by the use ofthese nanoclays and, sincemore recently, they also offer greatadvantages in the formulation of active packaging technolo-gies based on bioplastics such as more efficient antioxidant,oxygen scavenging or antimicrobial biopackaging, whichhas more direct implications in increasing packaged foodsquality and safety (Busolo, Ocio, & Lagaron, 2009;Lagaron, Gimenez, & Cabedo, 2007; Lopez-Rubio et al.,2006; Sanchez-Garcia, Ocio, Gimenez, & Lagaron, 2008).

Fig. 1 shows, as an example, that the performance ofbiopolyesters, in terms of oxygen barrier, is alreadysignificantly improved by melt compounding addition offood-contact complying nanoclays (Sanchez-Garcia,Gimenez, & Lagaron, 2007). Although in comparison withPLA, the PLA nanocomposite approaches more closely thebarrier performance of the petroleum-based polyester coun-terpart polyethylene terephthalate (PET), it does not yet out-perform the polyester oxygen barrier and furtheroptimization work is required. On the other hand, the nano-clay-based PHB does already outperform PET (Sanchez-Garcia et al., 2007) and, hence, this microbial biopolymerhas a good potential in food packaging applications.

As the worldwide production capacity of biopolyesterscontinues to grow, their cost will soon be comparable to theirpetroleum-based counterparts. Currently, it is estimated thatthe consumption of petroleum-based plastics amounts to ca.52 million tons/year vs. only ca. 750,000 tons/year for bio-plastics. Ideally, the biopolymers cost should be below2 €/kg for mass replacement of their petroleum-based coun-terparts. Food-contact complying nanoclays, on the otherhand, are currently mass produced. Depending on the grade,their cost can be below 10 €/kg (information provided byNanoBioMatters S.L., Spain), fact that together with the rec-ommended low dosages, i.e. typically below 5 wt.-%, con-vert these nanoadditives in truly accessible commoditiesfor food biopackaging applications.

Other nanofillersMost applications of nanocomposites in bioplastics for

packaging have made use of laminar clays, but also, tosome extent, of carbon nanotubes (Sanchez-Garcia,Lagaron, et al., 2010) and nanoparticles of metals and oxides(Travan et al., 2009). However, there are other types of rein-forcing elements such as biodegradable cellulose nano-whiskers (CNW) and nanostructures obtained byelectrospinning, which are very promising in a number ofapplication fields (Huang, Zhang, Kotaki, & Ramakrishna,2003; Lopez-Rubio et al., 2007; Olsson et al., 2010;Sanchez-Garcia, Gimenez, & Lagaron, 2008; Torres-Giner,Gimenez, & Lagaron, 2008). The use of biobased nanofillersto reinforce bioplastics has the additional value of generatingfully biobased formulations. These nanobiofillers (CNWandelectrospun nanofibers) have a very large surface to massratios (up to 103 higher than amicrofiber), excellent mechan-ical strength (this is true for the CNW and for some rein-forced electrospun fibres), flexibility, lightness and, insame cases, edibility since they can be made of food hydro-colloids (Capadona et al., 2009; Helbert, Cavaill�e, &Dufresne, 1996; Rojas, Montero, & Habibi, 2009). As previ-ously commented for the clay-based nanocomposites, theresulting properties of nanocomposites with cellulose fibresare strongly related to the dimensions and aspect ratio of thefibres (shifting from micro- to nanosized fibres improve-ments in optical and mechanical properties have beenobserved), as well as to the compatibility with the polymer

614 J.M. Lagaron, A. Lopez-Rubio / Trends in Food Science & Technology 22 (2011) 611e617

matrix (Dubief, Samain, & Dufresne, 1999; Hubbe, Rojas,Lucia, & Sain, 2008; Siaueira, Bras, & Dufresne, 2009).Aspect ratios are mainly related to the origin of the celluloseused and to the nanowhisker preparation conditions (AziziSamir, Alloin, & Dufresne, 2005). The advantage of applica-tion of these nanomaterials has already been considered inthe controlled release of bioactive substances in the pharma-ceutical and biomedical fields and can also be applied asreinforcing fillers (Sanchez-Garcia & Lagaron, 2010). Otheruses include the controlled release of active and bioactivecompounds in food packaging applications, as well as forthe nanoencapsulation of functional added-value foodadditives (Fernandez, Torres-Giner, & Lagaron, 2009;Lopez-Rubio, Sanchez, Sanz, & Lagaron, 2009).

Challenges and strategiesIn the bioplastics field the two main challenges are asso-

ciated with functionality, specifically generating reproduc-ible performance of bioplastics as petroleum-basedcounterparts, and achieving truly positive life-cycle analy-sis, i.e. achieving the goal of carbon neutral materials orminimizing fossil energy consumption. In these issues, asthe physicist Richard P. Feynman (1959) anticipated, “thereis plenty of room at the bottom”, i.e. there is no doubt thatnanotechnology will play a significant role, due to the po-tential property enhancements that can be achieved incor-porating nanoparticles. Since more recently, there is alsothe debate of potential competition between the use ofcrops for foods and to obtain biobased products, in whathas been claimed as the cause for recent increases in theprice of foods. The latter issue is perhaps not so relevantwhen it comes to bioplastics, since consumption of foodcompeting resources to make biobased plastics is currentlyvery small (Carus & Piotrowski, 2009). In any case, as bio-plastics demand and production grows bigger in the future,this issue can surely be minimized by, for instance, valor-isation of food by-products and by optimization of micro-bial-based plastics (Awarenet, 2004; Beccari et al., 2009).

Regarding nanoparticles, it is reckoned that to achievethe level of performance associated to the use of nanotechsa high dispersion should be achieved in the bioplastic ma-trix. Hence, nanoparticles dispersion still remains a chal-lenge for the full delivery of the expected properties asannounced by the early modelling work. There are severaltechnologies to achieve nanodispersion in biopackagingmaterials being the most common, in situ polymerization,dispersion in solution and dispersion via melt-blending.Despite the two formers being more efficient in achievingnanodispersion in most cases, the latter route, less efficientin achieving dispersion, is without doubt the mostdemanded technology from an applied viewpoint, becauseit makes use of industry available machinery and processesto convert plastics into final articles. Other emerging pro-cessing routes to achieve nanodispersion are ball milling,multiple nanolayer extrusion and vapour depositionnanocoatings.

As stated above most nanocomposite technologies in themarket today make use of chemical or otherwise modifiedcommodity layered 2:1 or 1:1 phyllosilicates, the so-callednanoclays. A chemical and/or physical modification isneeded to both compatibilize highly hydrophilic clayswith the more organic apolar chemical constitution ofmost thermoplastic biopolyesters and to increase the clayintergallery space (basal space between adjacent layers),hence facilitating both intercalation and exfoliation, i.e.nanodispersion, of the clay laminar components in the ma-trix during compounding. In the food chain, special cautionis needed because the modifications should comply with thestringent migration regulations, i.e. functional barrier sta-tus, and preferably make use of food-contact approved sub-stances as valid modifiers. Currently, many of the existingnanoadditives, such as those modified with some ammo-nium salts which are commercially available, do not com-ply with, for instance, the current European food-contactdirective issued by the European Food Safety Authority(EFSA) (Commission Directive 2007/19/CE, 2007).

Therefore, it is a very important concern that most of thenanocomposite formulations (first generation nanocompo-sites, i.e. containing standard or general purpose organic-modified nanoclays) in the market are currently makinguse of ammonium salts as organophilic chemical modifiers,which have been devised to enhance the properties of engi-neering polymers in structural applications. However, forfood packaging applications, as mentioned above, onlyfood-contact approved materials and additives should beused, and should do so below their corresponding thresholdspecific migration levels. Thus, second generation nano-composites, specifically designed to comply with currentregulations and, at the same time, be cost effective and spe-cifically formulated to target particular materials (includingbiopolymers), materials properties or production technolo-gies are more suitable for the food biopackaging market.In essence, second generation nanocomposites refer to ma-terials with targeted specifications rather than wide spec-trum generic formulations.

In general, there is a lack of knowledge about the impactof nanomaterials when inserted into bioplastics during ser-vice. For instance, very little is known about their stabilityduring processing and potential toxicity issues related todecomposition and/or migration and also as to how theywill affect the actual inherent bioplastic migration levelsand the current establishment of afterlife disposal channelssuch as incineration, composting or recycling. However,and regarding this issue, the prospects for natural additivessuch as food-contact complying nanoclays, essentially mi-croparticles, and nanobiofibers due to edibility and/or re-sorbability or biocompatibility may not be of so muchconcern in biopackaging. For instance, regarding the after-life disposal, we have found out in our research that nano-clays in biodegradable matrices do not delaybiodegradation during composting, since it is a processthat occurs from the outside towards the inside and that

615J.M. Lagaron, A. Lopez-Rubio / Trends in Food Science & Technology 22 (2011) 611e617

the nanoclays, due to their inherent high surface energy,re-attach to each other to become microparticles of soilonce the polymer matrix disappears (Lagaron & Fendler,2009). Similarly, several studies have demonstrated thataddition of nanoclays to various synthetic polymers led toenhanced or accelerated degradation in comparison withthe kinetics observed for the neat polymers (Kumanayaka,Parthasarathy, & Jollands, 2010; Qin, Zhao, Zhang, Chen,& Yang, 2003; Tidjani & Wilkie, 2001). As a result, nano-composites containing nanoclays can be regarded, in thissense, as more environmentally friendly materials, evenwhen the matrix is a synthetic polymer. When the disposalroute is incineration, it has been observed that, at elevatedtemperatures a gradual decomposition of the surfactant inthe surface of the nanoclays takes place with the conse-quent removal of the polymeric matrix molecules fromthe exfoliated particles, leading to aggregation of theselayers which result in non-colloidal microcomposite parti-cles (Huang, Lewin, Tang, Fan, & Wang, 2008).

Regarding inherent nanoparticle hazard assessment, due totheir small size, nanoparticles are generally much morereactive than their corresponding macro-counterparts. But itis also true that as a result of this, much smaller filler loadingsare typically required, and hence added to the matrix, toachieve the desired properties. The large surface area of nano-particles allows a greater contact with cellular membranes, aswell as greater capacity for absorption and migration (Li &Huang, 2008). Therefore, assessment of the effects of nano-particles in food packaging materials such as migration tofoods, and potential bioaccumulation needs to be consideredin the expected dosages. Currently, data on toxicity and oralexposure of nanoparticles are extremely limited and contro-versial when it comes to the studied dosages. In addition,the small size of many nanoparticles causes them to take onunique chemical and physical properties that are differentfrom their macroscale chemical counterparts. This impliesthat their toxicokinetic and toxicity profiles cannot be extrap-olated from data on their equivalent non-nanoforms. Thus, therisk assessment of nanoparticles has to be performed ona case-by-case basis (Munro, Haighton, Lynch, & Tafazoli,2009). However, it is also very important to differentiatebetween three-dimensional nanoparticles (spherical or other-wise 3D nanoparticles such as nanometals), which are capableof penetrating the cell membranes, bi-dimensional nanopar-ticles (nanofibers, with only nanodimensions in the 2Dcross-section), which are less likely to penetrate cell wallsand the least concerned, one dimensional nanoparticles(nanoclays with only one nanodimension in the thickness di-rection). Thus, nanoclays should be considered aside becausein essence they are heat stable microparticles, which remainsuch all along the process of production and commercializa-tion and to a significant extent also as two-dimensional micro-particles within the biopolymer matrix during service. In anycase, the general risk assessment of migration products result-ing from packaging materials has and continues to posea difficult challenge. As a general rule, nanocompositeswithin

the European Union must comply with the EFSA total migra-tion limit of 10 mg/dm2, with the functional barrier stringentmigration level of 0.01 mg/kg of food or food simulant and/or with the specific migration levels for their constituents incase they comprise food-contact components (CommissionDirective 2007/19/CE that modifies Directive 2002/72/CE).Some studies have shown that upon melting nanocompositeplastic films, some clay accumulation appears to occur atthe surface of the materials generating a clay-containing bar-rier (Hao, Lewin, Wilkie, & Wang, 2006; Lewin & Tang,2008). However, information about actual migration to foodor food simulants is very scarce. In a recent study, Schmidtet al. (2009) characterized the migration and size of migratedparticles from PLA nanocomposites in a fatty food stimulant(ethanol). The previous authors used an analytical platformconsisting of asymmetrical flow field-flow fractionation(AF4) coupled with multi-angle light scattering (MALS) andinductively coupled plasma mass spectrometry (ICP-MS).Even though an increase in total migration was observed forthe nanocomposite in comparison with the neat PLA matrix,the migration levels were below the total migration limitand no traces of nanoclayswere detected in themigrate. Theseresults confirm the theoretical predictions by �Simon,Chaudhry, and Bakos (2008), who concluded that consideringa polymer matrix with low dynamic viscosity that did not in-teract with the nanoparticles, only very small particles witha diameter of about 1 nmwere expected tomigrate. In anotherstudy dealing withmigration into foods, starch/clay nanocom-posites were characterized and, although an increase in the sil-ica content was observed in the vegetables tested, which wasascribed to certain nanoclay migration, the overall migrationlimit after contact with common simulants did comply withactual regulations and European directives on biodegradablematerials (Avella et al., 2005). Mauricio-Iglesias, Peyron,Guillard, and Gontard (2010) used the aluminium and siliconcontent in several food simulants as potential markers to fol-low the migration of montmorillonite nanoclay particlesfrom wheat gluten nanocomposites. The main conclusionobtained was that the greatest migration of these elementsoccurred in the low pH food simulant, being the total migra-tion below the limit established by EFSA. In view of theresults, it seems clear that the current evidence suggests thatno specific relevant issues are to be expected with nanoclaysin food contact but more research is needed in this area, notonly investigating the migration and potential toxicity ofnanoclays, but more importantly also of other nanoparticlesused in food packaging structures.

Finally, it is envisaged that the potential strategies toovercome the above and other pending issues will comefrom focussing the research efforts and political strategieson the following items:

- Boosting the creation of nanotechnology industry-based platforms with solid knowledge of the problemsto solve and of the legislation and commercializationbarriers ahead. Open innovation and collaborative

616 J.M. Lagaron, A. Lopez-Rubio / Trends in Food Science & Technology 22 (2011) 611e617

action towards more rapid product development willstrongly benefit the area. Development and commer-cialization of commodity products are a must. Thus,nanotechnology will only contribute to widespread theuse of bioplastics through the balancing of their proper-ties if they become a commodity in terms of pricing andvolumes. This could significantly happen in developingcountries since the raw materials availability for bioder-ived products is vast and venture capital grows interest.

- Focussing R&D efforts in order to provide real valuefor nanobiocomposites, i.e. developing the underpin-ning science and technology to understand and controlthe composition/properties/processing/aging relation-ship of nanobiocomposites.

- Developing new bioplastics and tailor-made reinforcingnanobioadditives that make use of only biobased prod-ucts and resources, particularly derived from valoriza-tion of food by-products.

- Establishing clear and knowledge-based legislationworldwide that defines nanoproducts and enables a clearassessment of the liability of existing ones in thevarious application fields and that provides conciseguidelines for the clearance route of new developments.It might be that there is no need to change legislation toaccommodate many existing nanomaterials and, there-fore, it is all related to complying with the currentglobal legislation for most of these. But then this hasto be clearly stated to industries and society to boostimplementation. According to FDA, it is products ona case-by-case scenario and not technologies what isto be regulated, and perhaps this should be the rightapproach.

- Deepening our understanding regarding the life-cycleanalysis of nanobiocomposites.

- Deepening our understanding about the potential toxic-ity of current and under development nanomaterials andof their nanobiocomposites. This should be carried outthrough the characterization of the stability of nanobio-composites during processing and shelf-life, full migra-tion studies and assessment of issues related to thevarious disposal channels.

References

Avella, M., De Vlieger, J. J., Errico, M. E., Fischer, S., Vacca, P., &Volpe, M. G. (2005). Biodegradable starch/clay nanocompositefilms for food packaging applications. Food Chemistry, 93,467e474.

Awarenet. (2004). Handbook for the prevention and minimisation ofwaste and valorisation of byproducts in European agro-food in-dustries. Deposito legal: BI-223-04.

de Azeredo, H. M. C. (2009). Nanocomposites for food packag-ing applications. Food Research International, 42,1240e1253.

Azizi Samir, M. A. S., Alloin, F., & Dufresne, A. (2005). Review ofrecent research into cellulosic whiskers, their properties and theirapplication in nanocomposite field. Biomacromolecules, 6,612e626.

Beccari, M., Bertin, L., Dionisi, D., Fava, F., Lampis, S., Majone, M.,et al. (2009). Exploiting olive oil mill effluents as a renewableresource production of biodegradable polymers througha combined anaerobiceaerobic process. Journal of ChemicalTechnology & Biotechnology, 84, 901e908.

Busolo, M. A., Ocio, M. J., Lagaron, J. M. (2009). Development ofantimicrobial PLA nanocomposites with silver containing layerednanoclays for packaging and coating applications.Annual Technical Conference (ANTEC), Conference Proceedings,pp. 236e239.

Cabedo, L., Gimenez, E., Lagaron, J. M., Gavara, R., & Saura, J. J.(2004). Development of EVOHekaolinite nanocomposites.Polymer, 45(15), 5233e5238.

Commission Directive 2007/19/CE (2007). Amending Directive 2002/72/EC relating to plastic materials and articles intended to comeinto contact with food. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do%3Furi¼OJ:L:2007:091:0017:0036:EN: PDF

Capadona, J. R., Shanmuganathan, K., Trittschuh, S., Seidel, S.,Rowan, S. J., & Weder, C. (2009). Polymer nanocomposites withnanowhiskers isolated from microcrystalline cellulose. Biomacro-molecules, 10(4), 712e716.

Carus, M., & Piotrowski, S. (2009). Land use for bioplastics. BioplasticsMagazine, 4, 45e49, [04,09].

Cyras, V. P., Manfredi, L. B., Ton-That, M. T., & V�azquez, A. (2008).Physical and mechanical properties of thermoplastic starch/mont-morillonite nanocomposite films. Carbohydrate Polymers, 73,55e63.

Dubief, D., Samain, E., & Dufresne, A. (1999). Polysaccharide mi-crocrystals reinforced amorphous poly(b-hydroxyoctanoate) nano-composite materials. Macromolecules, 32(18), 5765e5771.

Fernandez, A., Torres-Giner, S., & Lagaron, J. M. (2009). Novel route tostabilization of bioactive antioxidants by encapsulation in elec-trospun fibers of zein prolamine. Food Hydrocolloids, 23(5),1427e1432.

Feynman, R. P. (1959). There is plenty of room at the bottom. AnnualMeeting of the American Physical Society, Caltech, California, 29thDecember 1959. http://www.zyvex.com/nanotech/feynman.html

Hao, J., Lewin, M., Wilkie, C. A., & Wang, J. (2006). Additionalevidence for the migration of clay upon heating of clay-polypro-pylene nanocomposites from X-ray photoelectron spectroscopy(XPS). Polymer Degradation and Stability, 91, 2482e2485.

Haugaard, V. K., Udsen, A. M., Mortensen, G., Hoegh, L., Petersen, K.,& Monahan, F. (2001). Food biopackaging, in biobased packagingmaterials for the food industry e status and perspectives”. InC. J. Weber (Ed.), A European concerted action (pp. 13e14),Copenhagen.

Helbert, W., Cavaill�e, C. Y., & Dufresne, A. (1996). Thermoplasticnanocomposites filled with wheat straw cellulose whiskers. Part I:processing and mechanical behaviour. Polymer Composites, 17(4),604e611.

Huang, N., Lewin, M., Tang, Y., Fan, C., & Wang, J. (2008). Studies onthe migration in PA6-OMMT nanocomposites: effect of annealing onmigration as evidenced by ARXPS (angle resolved X-rayphotoelectron spectroscopy). Polymers for Advanced Technologies,19, 993e1001.

Huang, Z. M., Zhang, Y. Z., Kotaki, M., & Ramakrishna, S. (2003). Areview on polymer nanofibers by electrospinning and their appli-cations in nanocomposites. Composites Science and Technology,63(15), 2223e2253.

Hubbe, M. A., Rojas, O. J., Lucia, L. A., & Sain, M. (2008). Cellulosicnanocomposites: a review. Bioresources, 3(3), 929e980.

Kumanayaka, T. O., Parthasarathy, R., & Jollands, M. (2010). Acceler-ating effect of montmorillonite on oxidative degradation of poly-ethylene nanocomposites. Polymer Degradation and Stability, 95,672e676.

Lagaron, J. M., Cabedo, L., Cava, D., Feijoo, J. L., Gavara, R., &Gimenez, E. (2005). Improving packaged food quality and safety.

617J.M. Lagaron, A. Lopez-Rubio / Trends in Food Science & Technology 22 (2011) 611e617

Part 2: nanocomposites. Food Additives and Contaminants, 22,994e998.

Lagaron, J. M., & Fendler, A. (2009). High water barrier nanobio-composites of metil cellulose and chitosan for film and coatingapplications. Journal of Plastic Film and Sheeting, 25(1), 47e59.

Lagaron, J. M., Gimenez, E., Cabedo, L. (2007). Preparing laminarnanocomposites that contain intercalated organic materials, usefule.g. for reinforcing plastic packaging and for controlled release ofpharmaceuticals. Patent number WO2007074184-A1.

Lagaron, J. M., Gimenez, E., & Sanchez-Garcia, M. D. (2008). Ther-moplastic nanobiocomposites for rigid and flexible food packagingapplications. In E. Chiellini (Ed.), Environmentally compatible foodpackaging. Cambridge: Woodhead Publishing Ltd.

Lagaron, J. M., & Lopez-Rubio, A. (2010). Latest developments andfuture trends in food packaging and biopackaging. In M. LauraPassos, & C. P. Ribeiro (Eds.), Innovation in food engineering newtechniques and products. CRC Press, ISBN 978-1-4200-8606-5.

Lewin, M., & Tang, Y. (2008). Oxidation-migration cycle in polypro-pylene-based nanocomposites. Macromolecules, 41, 13e17.

Li, S. D., & Huang, L. (2008). Pharmacokinetics and biodistribution ofnanoparticles. Molecular Pharmaceutics, 5(4), 496e504.

Lopez-Rubio, A., Gavara, R., & Lagaron, J. M. (2006). Bioactivepackaging: turning foods into healthier foods through biomaterials.Trends in Food Science and Technology, 17(10), 567e575.

Lopez-Rubio, A., Lagaron, J. M., Ankerfors, M., Lindstrom, T.,Nordqvist, D., Mattozzi, A., et al. (2007). Enhanced film formingand film properties of amylopectin using micro-fibrillated cellu-lose. Carbohydrate Polymers, 68(4), 718e727.

Lopez-Rubio, A., Sanchez, E., Sanz, Y., & Lagaron, J. M. (2009).Encapsulation of living bifidobacteria in ultrathin PVOH electro-spun fibers. Biomacromolecules, 10, 2823e2829.

Ludue~na, L. N., Alvarez, V. A., & Vasquez, A. (2007). Processing andmicrostructure of PCL/clay nanocomposites. Materials Science andEngineering: A, 460, 121e129.

Marras, S. I., Kladi, K. P., Tsivintzelis, I., Zuburtikudis, I., &Panayiotou, C. (2008). Biodegradable polymer nanocomposites: therole of nanoclays on the thermomechanical characteristics and theelectrospun fibrous structure. Acta Biomaterialia, 4(3), 756e765.

Mauricio-Iglesias, M., Peyron, S., Guillard, V., & Gontard, N. (2010).Wheat gluten nanocomposite films as food-contact materials: mi-gration tests and impact of a novel food stabilization technology (highpressure). Journal of Applied Polymer Science, 116, 2526e2535.

Munro, I. C., Haighton, L. A., Lynch, B. S., & Tafazoli, S. (2009).Technological challenges of addressing new and more complexmigrating products from novel food packaging materials. FoodAdditives and Contaminants, 26(12), 1534e1546.

Okada, A., Kawasumi, M., Kurauchi, T., & Kamigaito, O. (1987).Synthesis of nylon 6-clay hybrid O. Polymer Preprint, 28, 447e448.

Olsson, R. T., Kraemer, R., Lopez-Rubio, A., Torres-Giner, S.,Ocio, M. J., & Lagaron, J. M. (2010). Extraction of microfibrils frombacterial cellulose networks for electrospinning of anisotropicbiohybrid fiber yarns. Macromolecules, 43, 4201e4209.

Park, H. M., Lee, W. K., Park, C. Y., Cho, W. J., & Ha, C. S. (2003).Environmentally friendly polymer hybrids: part I. Mechanical,thermal, and barrier properties of the thermoplastic starch/claynanocomposites. Journal of Materials Science, 38, 909e915.

Petersen, K., Nielsen, P. K., Bertelsen, G., Lawther, M., Olsen, M. B.,Nilsson, N. H., et al. (1999). Potential of biobased materials forfood packaging. Trends in Food Science and Technology, 10,52e68.

Petersson, L., & Oksman, K. (2006). Biopolymer based nanocompo-sites: comparing layered silicates and microcrystalline cellulose asnanoreinforcement. Composites Science and Technology, 66,2187e2196.

Qin, H., Zhao, C., Zhang, S., Chen, G., & Yang, M. (2003). Photo-oxidative degradation of polyethylene/montmorillonite nanocompo-site. Polymer Degradation and Stability, 81(3), 497e500.

Reguera, J., Lagaron, J. M., Alonso, M., Reboto, V., Calvo, B., &Rodriguez-Cabello, J. C. (2003). Thermal behavior and kineticanalysis of the chain unfolding and refolding and of the concom-itant nonpolar solvation and desolvation of two elastin-likepolymers. Macromolecules, 36, 8470e8476.

Rojas, O. J., Montero, G. A., & Habibi, Y. (2009). Electrospun nano-composites from polystyrene loaded with cellulose nanowhiskers.Journal of Applied Polymer Science, 113(2), 927e935.

Sanchez-Garcia, M. D., Gimenez, E., & Lagaron, J. M. (2007). NovelPET nanocomposites of interest in food packaging applications andcomparative barrier performance with biopolyester nanocompo-sites. Journal of Plastic Film and Sheeting, 23(2), pp. 133e148.

Sanchez-Garcia, M. D., Gimenez, E., & Lagaron, J. M. (2008).Morphology and barrier properties of solvent cast composites ofthermoplastic biopolymers and purified cellulose fibers.Carbohydrate Polymers, 71(2), 235e244.

Sanchez-Garcia, M. D., Hilliou, L., & Lagaron, J. M. (2010). Nano-biocomposites of carrageenan, zein, and mica of interest in foodpackaging and coating applications. Journal of Agricultural andFood Chemistry, 58, 6884e6894.

Sanchez-Garcia, M. D., & Lagaron, J. M. (2010). On the use of plantcellulose nanowhiskers to enhance the barrier properties of poly-lactic acid. Cellulose, 17(5), 987e1004.

Sanchez-Garcia, M. D., Lagaron, J. M., & Hoa, S. V. (2010). Effect ofaddition of carbon nanofibers and carbon nanotubes on propertiesof thermoplastic biopolymers. Composites Science and Technol-ogy, 70(7), 1095e1105.

Sanchez-Garcia, M. D., Ocio, M. J., Gimenez, E., & Lagaron, J. M.(2008). Novel polycaprolactone nanocomposites containing thy-mol of interest in antimicrobial film and coating applications.Journal of Plastic Film and Sheeting, 24(3e4), 239e251.

Schmidt, B., Petersen, J. H., Bender Koch, C., Plackett, D.,Johansen, N. R., Katiyar, V., et al. (2009). Combining asymmetricalflow field-flow fractionation with light scattering and inductivelycoupled plasma mass spectrometric detection for characterizationof nanoclay used in biopolymer nanocomposites. Food Additivesand Contaminants, 26(12), 1619e1627.

Shonaike, G. O., & Advani, S. G. (Eds.). (2003). Advanced polymericmaterialse Structure property relationships. Boca Raton: CRCPress.

Siaueira, G., Bras, J., & Dufresne, A. (2009). Cellulose whiskers versusmicrofibrils: influence of the nature of the nanoparticle and itssurface functionalization on the thermal and mechanical propertiesof nanocomposites. Biomacromolecules, 10(2), 425e432.

�Simon, P., Chaudhry, Q., & Bakos, D. (2008). Migration of engineerednanoparticles from polymer packaging to food e a physicochemi-cal view. Journal of Food and Nutrition Research, 47(3), 105e113.

Tidjani, A., & Wilkie, C. A. (2001). Photo-oxidation of polymeric-in-organic nanocomposites: chemical thermal stability and fire re-tardancy investigations. Polymer Degradation and Stability, 74(1),33e37.

Torres-Giner, S., Gimenez, E., & Lagaron, J. M. (2008). Characteriza-tion of the morphology and thermal properties of zein prolaminenanostructures obtained by electrospinning. Food Hydrocolloids,22, 601e614.

Travan, A., Pelillo, C., Donati, I., Marsich, E., Benincasa, M.,Scarpa, T., et al. (2009). Non-cytotoxic silver nanoparticle-poly-saccharide nanocomposites with antimicrobial activity.Biomacromolecules, 10(6), 1429e1435.

Wan, C., Qiao, X., Zhang, Y., & Zhang, Y. (2003). Effect of differentclay treatment on morphology and mechanical properties ofPVC-clay nanocomposites. Polymer Testing, 22, 453e461.

Xu, Y., Ren, X., & Hanna, M. A. (2006). Chitosan/clay nanocompositefilm preparation and characterization. Journal of Applied PolymerScience, 99(4), 1684e1691.

Yu, Y. H., Lin, C. Y., Yeh, J. M., & Lin, W. H. (2003). Preparation andproperties of poly(vinyl alcohol)eclay nanocomposite materials.Polymer, 44(12), 3553e3560.