Effect of calcium and/or barium crosslinking on the physical and antimicrobial properties of natamycin-loaded alginate films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The preparation of alginate films with suitable properties requires a two-step contact with reticulating agents: initially a weakly structured pre-film is formatted which is further crosslinked in a second stage by immersion in a more concentrated solution. The present work evaluated the effects of a combined crosslinking procedure using calcium and barium ions on the physical and morphological properties of alginate-based films containing natamycin as antimicrobial agent. The release behavior of natamycin in water was evaluated as well as the antimicrobial activity against four target microorganisms, which are common cheese product contaminants. Films attributes were affected by the type of ion used in the second stage while the natamycin release rate and the antimicrobial activity were influenced by the ion used in the first stage. Films crosslinked with Ba2+ in the first and Ca2+ in the second stage (Ba-Ca films) exhibited physical properties very similar to films crosslinked with calcium in both stages. Release kinetics of natamycin in water fitted well to Fick's second law diffusional model, with effective diffusivity values ranging from 0.40 x 10(-11) to 1.74 x 10(-11) cm(-2)/s. Ba-Ca films presented the lowest natamycin diffusion coefficient and the smallest inhibition zone diameter against the four microorganisms tested. (C) 2014 Elsevier Ltd. All rights reserved.572494501Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Programa Ciencia (Portugal)COMPETE (Portugal) [PEst-C/EQB/UI0102/2011]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)COMPETE (Portugal) [PEst-C/EQB/UI0102/2011

Influence of natamycin loading methods on the physical characteristics of alginate active films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Natamycin, an antimicrobial agent sparingly soluble in water, was incorporated into alginate films in order to produce antimicrobial packaging, using three different approaches: the conventional loading method, when natamycin is added directly to the polymeric aqueous film-forming solution; the immersion procedure, by which a previously prepared films is contacted with natamycin solution, and by the supercritical solvent impregnation (SSI) method, with loading tests performed in CO2 containing natamycin, with and without addition of cosolvent (ethanol, 10% molar). The loading capacities were evaluated, as well as the influence on physical attributes of the films and on the release behavior of natamycin in water. The conventional method led to films heterogeneities with high surface roughness, and the immersion technique evinced several disadvantages like low incorporation yields, and negative influence on water vapor permeability and on the swelling degree of the film. The supercritical method showed that longer contact times and the use of ethanol as a cosolvent increased the natamycin loading yields and led to homogeneous films, where SSI (CO2 + EtOH) process produced visually attractive and tranlucent films. (C) 2013 Elsevier B.V. All rights reserved.767482Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

O monitoramento de processos físicos de esterilização em hospitais do interior do estado de Goiás

Estudo descritivo com o objetivo de identificar a realização de controles físicos, químicos e biológicos dos processos de esterilização pelo vapor saturado sob pressão e em estufas de Pasteur em Centros de Material e Esterilização - CME. Os dados foram obtidos por meio de entrevista ao responsável pelo CME do maior hospital de todas as cidades do interior do Estado de Goiás, com número de habitantes igual ou superior a 20.000, no período de agosto de 2005 a junho de 2006. Participaram 44 municípios. Foi utilizado o programa SPSS, para análise. Em 31 (94,0%) hospitais não havia enfermeiros exclusivos no CME, os responsáveis eram técnicos e auxiliares de enfermagem. A maioria não realizava os controles físicos, químicos e biológicos dos processos de esterilização e, em apenas um, esses eram realizados simultaneamente. O descumprimento da monitorização dos ciclos de esterilização, impedindo a garantia da qualidade dos processos, representa risco à população assistida