Please cite this article in press as: A.R.V. Ferreira, et al., Int. J. Biol. Macromol. (2014), http://dx.doi.org/10.1016/j.ijbiomac.2014.04.022 ARTICLE IN PRESS G Model BIOMAC-4289; No. of Pages 6 International Journal of Biological Macromolecules xxx (2014) xxx–xxx Contents lists available at ScienceDirect International Journal of Biological Macromolecules j ourna l h o mepa ge: www.elsevier.com/locate/ijbiomac Biodegradable films produced from the bacterial polysaccharide FucoPol Ana R.V. Ferreira a , Cristiana A.V. Torres a , Filomena Freitas a , Maria A.M. Reis a , Vítor D. Alves b , Isabel M. Coelhoso a,∗ a REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal b CEER-Biosystems Engineering, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal a r t i c l e i n f o Article history: Received 6 February 2014 Received in revised form 2 April 2014 Accepted 11 April 2014 Available online xxx Keywords: Bacterial exopolysaccharide Films characterization Barrier properties a b s t r a c t FucoPol, an exopolysaccharide produced by Enterobacter A47, grown in bioreactor with glycerol as carbon source, was used with citric acid to obtain biodegradable films by casting. The films were character- ized in terms of optical, hygroscopic, mechanical and barrier properties. These films have shown to be transparent, but with a brown tone, imparting small colour changes when applied over coloured surfaces. They were hydrophilic, with high permeability to water vapour (1.01 × 10 -11 mol/m s Pa), but presented good barrier properties to oxygen and carbon dioxide (0.7 × 10 -16 mol m/m 2 s Pa and 42.7 × 10 -16 mol m/m 2 s Pa, respectively). Furthermore, films have shown mechanical properties under tensile tests characteristic of ductile films with high elongation at break, low tension at break and low elastic modulus. Although the obtained results are promising, films properties can be improved, namely by testing alternative plasticizers, crosslinking agents and blends with other biopolymers. Taking into account the observed ductile mechanical properties, good barrier properties to gases when low water content is used and their hydrophilic character, it is foreseen a good potential for FucoPol films to be incorporated as inner layer of a multilayer packaging material. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Petrochemical-based plastics, such as polyethylene terephtha- late (PET), polyethylene (PE), polypropylene (PP) and polyamide (PA), have been intensively and increasingly used in food pack- aging because they are manufactured at a low-cost, presenting simultaneously interesting functional characteristics. They are heat sealable, possess good mechanical and thermal properties, as well as, suitable barrier properties to gases, aroma compounds and microorganisms [1,2]. However, their use must be reduced because they are non-biodegradable and their recyclability is limited, which causes a serious environmental impact [3]. This problem can be overcome by replacing synthetic polymers by natural/bio-based polymers [3]. Most of the bio-based polymers obtained from renewable resources are biodegradable. They may be classified according to the production method or source as: polymers directly extracted from biomass (such as plant or algal polysaccharides and proteins), polymers obtained from renewable bio-based monomers (such as polylactic acid) or polymers produced by microorganisms ∗ Corresponding author. Tel.: +351 212 948 302; fax: +351 212 948 550. E-mail address: imrc@fct.unl.pt (I.M. Coelhoso). (such as polyhydroxyalkanoates and bacterial exopolysaccharides) [4,5]. Polysaccharides are usually nontoxic and widely available [6]. They have hydrophilic character, usually forming strong films with poor water vapour barrier properties [6–8]. Nevertheless, polysac- charide films are excellent gas, aroma and lipid barriers and show good mechanical properties. The film forming capacity and film properties of different polysaccharide materials, including, chi- tosan [9–11], starch [12–15], alginate [16,17] and carrageenan [18] have been intensively studied. Microbial polysaccharides represent an alternative to others recovered from animal, algal or plant sources, because their pro- duction is not dependent on climatic or seasonal impacts. The high molecular structure variability, availability and the proper- ties of these polysaccharides turns them attractive to a wide range of applications, ranging from chemical industry to food, medicine and cosmetics [19]. Some microbial polysaccharides, such as gellan, kefiran and xanthan, have been studied to produce biodegradable films with potential final use on packaging materials [20–22]. Such microbial polysaccharide films could be applied as primary packag- ing (as stand-alone films) or coatings. However, their hydrophilic nature limits their use as moisture barrier. Thus, development of biodegradable films based on polymer blends or multilayer films http://dx.doi.org/10.1016/j.ijbiomac.2014.04.022 0141-8130/© 2014 Elsevier B.V. All rights reserved.