Characterization of Fucopol Films for Food Packaging

Transcription

1 Characterization of Fucopol Films for Food Packaging Ana R. V. Ferreira 1, Cristiana A. V. Torres 1, Filomena Freitas 1, Maria Reis 1, Vítor D. Alves 2, Isabel M. Coelhoso 1 1. REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, Caparica, Portugal 2. CEER-Biosystems Engineering, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, Lisbon, Portugal 1

2 State of art Plastics: Packaging sector, on Europe, uses 18 million tonnes of plastic. PE-LD & PE-LLD PE-HD PP PET Global plastics production increased to 288 million tonnes in European production was 57 million tonnes and collected post-consumer was 25 million tonnes. Landfill disposal 38,1 Packaging 39,4% Plastic packaging is essential for processing, storing, transporting, protecting and preserving food. Others 22,4% Building & Construction 20,3% Automotive 8,2% Electrical & Electronic 5,5% Agriculture 4,2% [Source: PlasticsEurope - Association of plastic manufacture 2013] Energy recoery 35,6 Recycling 26,3 2

3 State of art Food Industry: Packaging materials by natural compounds Biopolymers The natural polysaccharides are polymer materials biologically produced, that exhibit unique functional properties and are environmentally friendly. Extracted from biomass Synthesized through bio-monomers Produced by microorganisms e.g. Pectin, starch, chitosan Polylactic acid (PLA) Polysaccharides PHAs Polysacharides: Plants Algae Animals Starch Pectin Carrageenan Alginate Chitin Chitosan 3

4 State of art Advantages Higher production rate Favorable to manipulation growth and / or production New/improved properties Microorganisms Xanthan Bacterial alginate Need to find low-cost substrates Disadvantages Cost of substrates Glycerol byproduct from biodiesel industry: European biodiesel productive capacity (2013): 25.2 million tonnes. European biodiesel production (2013): 10,2 million tonnes. 10% of biodiesel production is glycerol. 4

5 FucoPol production and characterization Fucose-containing exopolysaccharide (FucoPol) The FucoPol is produced by Enterobacter strain A47 (DSM 23139). Carbon source: Glycerol byproduct from biodiesel industry. Operating conditions: Batch and fed-batch mode Microscopic observation of Enterobacter sp. broth sample Temperature 30.0±0.1ºC ph 6.8±0.05 Aeration rate Stirring rate vvm rpm Reis M. et al; Fucose-containing bacterial biopolymer; International Publication Number WO 2011/ A2, June

6 FucoPol production and characterization FucoPol characteristics: Heteropolysaccharide Anionic character Molecular weight: 0.9 x x 10 7 Purification method: Diafiltration 6

7 FucoPol production and characterization FucoPol characteristics: Heteropolysaccharide Anionic character Molecular weight: 0.9 x x 10 7 Chemical composition: Fucose Galactose Glucose Acyl groups Pyruvate Acetate Succinate 7

8 Results Films preparation Dissolve dried FucoPol in 1 st deionized water 2 nd Add citric acid Transfer to Teflon Petri dishes 3 rd Dry at 40ºC during 12h Flexible films Bending without breaking Homogeneous Biodegradable SEM image Surface Cross-section 8

9 Results Films characterization Transparency: Transparency FucoPol (Present work) 3.7 ± 0.4 Chitosan 1%(w/w)* 1.1 ± 0.1 GalactoPol (From Pseudomonas Oleovorans) 5.9 ± 0.7 *Rivero, S.; Composite and bi-layer films based on gelation and chitosan; 2009; J. Food Eng

10 Results Films characterization Transparency: Transparency FucoPol (Present work) 3.7 ± 0.4 Chitosan 1%(w/w)* 1.1 ± 0.1 GalactoPol (From Pseudomonas Oleovorans) 5.9 ± 0.7 Colour alteration: o Colour alteration is perceived by human eye ( Eab > 3) o Decrease in colour saturation Parameters a* and b* of the CIELAB system for coloured paper sheets uncovered (diamonds) and covered (circles) by the test films and calculated colour differences. *Rivero, S.; Composite and bi-layer films based on gelation and chitosan; 2009; J. Food Eng

11 Results Films characterization Water vapour sorption isotherm: GAB model m m C K 0.071± ± ±0.009 Water vapour sorption ability similar to pectin from citrus fruits, except for aw>0.8. The isotherm behavior is very similar to another bacterial polysaccharide (GalactoPol). High solubility in liquid water Film disintegration Contact angle: FucoPol films contact angle: 61±4 0 Hydrophilic surface 11 * V.D. Alves et al. Carbohydrate Polymers 83 (2011)

12 Results Films characterization Water vapour permeability: Salt Water activity at 30ºC T = 30ºC T RH Desiccator CH3COOK Petri dish NaCl Film Salt solution Salt solution Mechanical properties: Tensile test Malleable films: High elongation at break Low Young modulus FucoPol (Present work) RH (%) WVP (10-11 mol m -1 s -1 Pa -1 ) ±0.2 GalactoPol* ±0.8 Chitosan** ±0.1 Citric acid effect Conditioned at Stress at break Elongation at break (%) Young modulus (Mpa) FucoPol 44.3% RH 3.1± ±4 2.8± * V.D. Alves et al. Carbohydrate Polymers 83 (2011) ** M. Pereda et al. Food Hydrocolloids 25 (2011)

13 Results Films characterization Gas barrier properties: Film RH (%) O 2 Permeability (mol m/m 2 s Pa) CO 2 Permeability (mol m/m 2 s Pa) Selectivity (α) FucoPol ± ± Good barrier properties to oxygen and carbon dioxide. Better selectivity than synthetic polymers. Starch* Carrageenan /pectin** _ Chitosan*** ± ± LDPE* PET* *N. Gontard et al. J. of Agricultural and Food Chemistry 44 (1996) **V.D. Alves Procedia Food Science (2011) ***P. Fajardo J. of Food Engineering, 101 (2010)

14 Results Blends preparation Blends preparation: Blends of FucoPol and Chitosan (maintaining constant the overall polymer concentration). Dissolve dried FucoPol in 1%wt acetic acid solution 1 st Dissolve Chitosan in 1%wt acetic acid solution Add glycerol (plasticizer) 2 nd Add citric acid Transfer to Teflon Petri dishes 3 rd Dry at 40ºC during 12h FucoPol Film FucoPol/Chitosan film 14

15 Results Blends characterization Blends solubity: FucoPol : Totally soluble in water Fucopol/Chitosan film: Solubility in water: 33.1 ± 7.7 % (w/w) Swelling in water: 4.7 ± 0.9 % (w/w) SEM image of EPS/Chitosan films Surface Cross-section Transparency Contact angle (º) Thickness (µm) FucoPol Films 3.7 ± ± 4 57 ± 4 Blends of Fucopol and Chitosan 4.1 ± ± ± 12 15

16 Conclusions FucoPol was able to produce cohesive films, either alone, or blended with Chitosan when dissolved in acidic solutions. Both films are transparent, flexible and ductile, due to the plasticizing effect of citric acid. FucoPol films are hygroscopic with low water vapour barrier properties, hydrophilic and soluble in water. However they present good barrier properties to gases. 16

17 On going work Blends of FucoPol and Chitosan Bi-layer of FucoPol and Chitosan Applications: Packaging material Layer in a multilayer film Ductile mechanical properties Hydrophilic character Good barrier properties to gases Characterization: Surface morphology Optical properties Barrier properties Fresh Fresh-cut Dehydrated Fruits Mechanical properties Slow down respiration rate and dehydratation Avoid enzymatic browning 17

18 Acknowledgements The authors would like to acknowledge FCT-MCTES, Portugal, for funding of project PTDC/AGR-ALI/114706/2009 New edible bioactive coatings for the improvement of food products quality. The authors would like to acknowledge COST Action FA Ana R. V. Ferreira also acknowledges FCT-MCTES, Portugal, for her scholarship SFRH/BD/79101/2011. Ana Rita Ferreira 18

19 Thank you! Ana Rita Ferreira 19