AZEREDO, H. M. C. de

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 Food Security UpdateAssociation NewsRegional ReportsStudent Reports andPerspectivesInternationalRegulatory UpdatePolicy PapersCalendar of EventsEdible Films and Coatings from Tropical FruitsHenriette M. C. AzeredoAbstractDifficulties have been encountered in disposing of the huge waste volumes generated by food packaging which ismostly non-biodegradable. Biopolymers have been studied as film forming materials to be used as biodegradableand/or edible films in food packaging. Edible films from fruit purees combine the film forming properties of biopolymerswith colors and flavors provided by pigments and aroma compounds from the fruit. The production of edible films fromfruit purees is an interesting way of reducing the huge post-harvest losses of tropical fruits in Brazil. The main limitationis related to the relatively poor mechanical and barrier properties of biopolymers when compared to syntheticpolymers. Nanofillers such as cellulose nanofibers have been shown as effective reinforcements to biopolymers butthere is a need for accurate information on the effects of nanomaterials on human health.IntroductionFood and beverage packaging accounts for more than half the worldwide packaging market (Stevens 2002). Thislarge volume of food packaging is meant to be quickly discarded, and the waste volume has not been greatly reducedby the recycling programs, because of high recycling costs and difficulties related to polymer separation (Azapagic andothers 2003).Several biopolymers such as polysaccharides or proteins have had their film-forming properties studied in order toproduce edible films to be used in food packaging. They are not intended to completely replace synthetic plastics butrather to improve their efficiency, thus reducing the amount of synthetic polymers required for each application. Anedible film is obtained by drying a thin layer of a film-forming material which is subsequently applied to a food surface;edible coatings, on the other hand, are produced by direct application of the film-forming material on the food surfaceand then drying.Fruit Purees as Film-forming MaterialsResearchers from USDA/ARS/WRRC (Albany, CA, USA) were the first to study fruit purees and concentrates asfilm-forming edible materials (McHugh and others 1996; McHugh and Senesi 2000; Senesi and McHugh 2002). Suchapplication of fruit purees is related to the presence of biopolymers (predominantly polysaccharides such as pectin,starch and cellulose derivatives) in their composition (Kaya and Maskan 2003). Edible films produced from fruit pureescan combine the mechanical and barrier properties from the film-forming components with the color and flavor providedby the pigments and volatile compounds of the fruit. Moreover, the production of edible films is an interesting andpromising way of using co-products of fruit processing. Films produced from fruit purees have been shown to be goodbarriers to gas diffusion but poor barriers to water vapor, properties which make them able to create a modifiedatmosphere when applied to fresh produce (Baldwin 1994).The variety of flavors found in tropical fruits is appreciated worldwide. Some tropical fruits, however, are hardly knownin temperate regions, because of the high costs and technical difficulties related to their importation from tropicalcountries. On the other hand, tropical fruit losses in Brazil are estimated to be higher than 40% of production, or about14 million tons per year (Silva et al. 2000). Most losses are due to inadequate handling, transportation, and storagefacilities. One of the primary goals of fruit processing is to convert perishable fresh fruits into more stable products,thereby reducing postharvest losses. The production of fruit purees is an interesting way of reducing such losses,since purees, in contrast to products made from whole fruits, can be produced from fruits with minor superficialdamage, provided the quality of the pulp is preserved. Fruit purees are usually commercialised as frozen purees, orprocessed into juices and nectars. The production of edible films and coatings can be a very interesting way of usingtropical fruit purees. Some studies have been made on edible films from tropical fruits such as banana (Sothornvit andPitak 2007) and mango (Sothornvit and Rodsamran 2008; Azeredo et al. 2009). Such films and coatings can functionas primary packaging materials for a variety of foods, such as fresh and processed fruits, cheeses, nuts, andconfectionery products, improving the protective efficiency of the synthetic secondary packaging, and incorporatingcolor and flavor onto the food surface.Limitations and Future ProspectsThe commercial use of films based on biopolymers has been limited because of their typically poor mechanical andbarrier properties when compared to synthetic polymers. Several nanocomposites have been developed by addingreinforcing compounds (nanofillers) to biopolymers, improving their properties and enhancing their cost-price-efficiency(Sorrentino and others 2007). A uniform dispersion of nanofillers leads to a very large matrix/filler interfacial area,which changes the molecular mobility and the consequent thermal and mechanical properties of the material. Highaspect ratio fillers such as nanofibers are particularly interesting because of their high specific surface area, providingbetter reinforcing effects (Azizi Samir and others 2005). Azeredo et al. (2009) reported that the incorporation ofcellulose nanofibers into a mango puree matrix noticeably enhanced the performance of the resulting films.However, there are many safety concerns about nanomaterials, as their size may allow them to penetrate into cellsand eventually remain in the human organism. While the properties and safety of the materials in their bulk form areusually well known, the nano-sized counterparts frequently exhibit different properties from those found at the macro-scale, and there is limited scientific data about their eventual toxicological effects. So the need for accurate informationEdible Films and Coatings from Tropical Fruits file:///F:/Documentos/ETTE/Publicacoes/Publicados/2010_WoFS_Edi...1 de 2 15/3/2010 11:02on the effects of nanomaterials on human health following chronic exposure is imperative before any nanostructuredfood packaging is available for commercialisation.ReferencesAzapagic, A, Emsley, A, and Hamerton, I. (2003) Polymers - The Environment and Sustainable Development. NewYork: Wiley & Sons; 234 pp.Azeredo, HMC, Mattoso, LHC, Wood, D, Williams, TG, Avena-Bustillos, RJ, and McHugh, TH. (2009) Nanocompositeedible films from mango puree reinforced with cellulose nanofibers. J. Food Sci. 74(5): N31-N35.Azizi Samir, MAS, Alloin, F and Dufresne, A (2005) Review of recent research into cellulosic whiskers, their propertiesand their application in nanocomposite field. Biomacromol. 6(2): 612-26.Baldwin, EA. (1994) Edible coatings for fresh fruits and vegetables: past, present, and future. In: Krochta, JM, Baldwin,EA and Nisperos-Carriedo, MO (Eds) Edible Coatings and Films to Improve Food Quality. Lancaster: Technomic; pp.25–64.Kaya, S and Maskan, A (2003) Water vapour permeability of pestil (a fruit leather) made from boiled grape juice withstarch. J. Food Eng. 57(3): 295-9.McHugh, TH, Huxsoll, CC and Krochta, JM (1996) Permeability properties of fruit puree edible films. J. Food Sci.61(1): 88-91.McHugh, TH and Senesi, E (2000) Apple wraps: a novel method to improve the quality and extend the shelf life offresh-cut apples. J. Food Sci. 65(3): 480-5.Senesi, E and McHugh, TH (2002) Film e coperture eduli com matrici a base di fruta. Ind. Aliment. 41(420): 1289-94.Silva, JS, Finger, FL and Corrêa, PC (2000) Armazenamento de frutas e hortaliças. In: Silva, JS (Ed). Secagem earmazenagem de produtos agrícolas. Viçosa: Aprenda Fácil. 469-502.Sorrentino, A, Gorrasi, G and Vittoria, V (2007) Potential perspectives of bionanocomposites for food packagingapplications. Trends Food Sci. Technol. 18(2): 84-95.Sothornvit, R and Pitak, N (2007) Oxygen permeability and mechanical properties of banana films. Food Res. Int.40(3): 365-70.Sothornvit, R and Rodsamran, P (2008) Effect of a mango film on quality of whole and minimally processed mangoes.Postharv. Biol. Technol. 47(3): 407-15.Stevens, ES (2002) Green Plastics: An introduction to the new science of biodegradable plastics. Princeton:Princeton University Press; 272 pp.Dr Henriette Azeredo is a Researcher in Food Packaging and Nanotechnology at Embrapa TropicalAgroindustry, R. Dra. Sara Mesquita, 2270, CEP 60511-110, Fortaleza, CE, Brazil; E-mail:ette@cnpat.embrapa.br © Copyright 2009, IFT and IUFoST IUFoST | IFT | CONTACT  Edible Films and Coatings from Tropical Fruits file:///F:/Documentos/ETTE/Publicacoes/Publicados/2010_WoFS_Edi...2 de 2 15/3/2010 11:02

Edible films and coatings from tropical fruits.

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Edible films and coatings from tropical fruits.

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