Desenvolvimento e caracterização de filme nanocompósito de base celulósica e sua avaliação como embalagem ativa antimicrobiana

• Autor(a) principal: Almeida, Germanna Wilk Reis de
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2891
• topic: Embalagens ativas; Nanocompósitos; Biopolímeros; Nanotecnologia; Active food package; Nanocomposite; Biopolymers; Nanotechnology; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS

The quality and microbiological safety os food products are priority for food industries. In this context, many reports have shown the applicability and efficiency of antimicrobial active food package in the inhibition of foodborne microorganisms. Further environment preservation and the need for new renewable sources to reduce use of petrochemical-based plastic packaging materials have increased the interest in biodegradable packaging materials. Nanocomposites exhibit significant improvements in the mechanical and physical properties of natural biopolymer films. Therefore nanotechnology represents a good possibility for generate new materials for food package applications. The objective of this work is to develop and character cellulose based nanocompósitos containing silver nanoparticles and montmorrilonite (MMT) clays, evaluating its physical, mechanical and microscopes properties, and to test its in vitro antimicrobial efficiency against foodborne microorganisms. Cellulose acetate films thickness and water vapor transmission rate (WVTR) was not affected by the nanomaterials addition. However silver nanoparticles did not have a good interaction with Nanofil® clay, increasing the average roughness (Ra) and oxygen transmission rate (OTR), and decreasing tensile strength of Nanofil® charged nancomposites. An intercalated form in the polymer was observed for Cloisite 10A® and Cloisite 30B® clays by transmission electronic microscopy (TEM), also showing tactoids structures for Nanofil® clay. Surface electronic microscopy (SEM) had shown the galleries structure of the polymer matrix containing MMT clays, and the presence of aggregates on acetate / Nanofil® nanocomposites surface. The antimicrobial action against Escherichia coli, Salmonella enterica sorotype Choleraesuis and Staphylococcus aureus, was observed by inhibition zones formed around the nanocomposites circles in disc diffusion tests, when incubated at 7 ºC. The specific growth rate of S. enterica and L. innocua was not affected by nanocomposites. The solvent casting method was able to produce cellulose acetate / clay bio-based nanocomposites with Cloisite 10A® and Cloisite 30B® clays, but the organoclays intercalated structure is not adequate for improving cellulose acetate based nanocomposites. Its use as antimicrobial active food package should be optimized for silver ions release.