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The electrospinning of cellulose acetate (CA) was investigated to develop biodegradable nanostructured membranes for the controlled release of drugs used to treat skin wounds. CA nanofibers were successfully prepared via the electrospinning in the four mixed solvents acetic acid : water; acetone : water; DMAc : acetone; DMAc : acetone : water. Design of experiments (DOE) was applied to see what combinations of parameters could affect the production of electrospun microfibers and nanofibers to optimize the process. The results of this work indicated that both the processing parameters and the solvent mixtures were responsible for the fiber diameter and nanostructure membrane appearance. The optimized condition for each solvent mixture was obtained and compared with each one of the others. The best conditions achieved were dimethylacetamida (DMAc) : acetone with 17% of CA, which provided homogeneous and free bead fibers with an average diameter of 295 nm. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

The performance of oxygen scavengers can be influenced by several conditions, such as temperature (T) and relative humidity (RH), which are considered to be the two major factors. Therefore, the development of new scavengers requires the study of their performance, with these conditions varied. In this paper, the response surface methodology (RSM) was used to study the performance of a newly developed oxygen scavenger sachet and to model the influences of T and RH and their interaction on the absorption capacity and rate constant of the developed sachet. Commercial oxygen scavenger sachets were used for comparison purposes. The oxygen absorption capacity and rate constant were evaluated with a 22 factorial design with a central point. The results showed that each absorber sachet presented a different behaviour and there were significant interactions between T and RH; so, the RSM was the most appropriate for these studies. The developed sachet presented a better performance compared with the commercial ones at 23°C and 53% RH, which represents the condition for commercialization at room temperature of foods of intermediary water activity, while in the extreme conditions (100% RH and 37°C) all sachets present a similar absorption capacity. Copyright © 2010 John Wiley & Sons, Ltd.

Porous macrospheres with controlled diameter were produced using N-methylolacrylamide and urea–formaldehyde resins synthesized in our laboratories. Hot silicon oil was used to form the porous macrospheres which were characterized by using infrared spectroscopy (FTIR), scanning electron microscopy, mercury porosimetry and surface area determination (BET). Porous macrospheres of amino-polymers were used as support in immunoassays type ELISA (enzyme linked immunosorbent assay) in which mouse immunoglobulin (IgG) was immobilized, and detected by rabbit anti-mouse immunoglobulin (a-IgG) labeled with horseradish peroxidase. Responses were obtained up to a dilution ratio of 1:4000 of the conjugate standard (1 mg/ml) and 10 μ g/ml of IgG solution to recover the spheres in pH=4.5.

O presente estudo teve como objetivo apresentar as mais recentes tendências do setor de embalagens alimentícias no mercado nacional e internacional. Foram abordados os conceitos de embalagens ativas e inteligentes, assim como suas funções, a composição, o formato, as reações químicas envolvidas, a forma de atuação de alguns tipos de embalagens, aplicações e os benefícios da sua utilização pela indústria de alimentos. Essas embalagens são planejadas e permitem interações com os alimentos a fim de manter a qualidade, a integridade, o frescor e a segurança do produto embalado. As inovações tecnológicas já são estabelecidas e bem aceitas em alguns países e conferem benefícios à conservação de grande variedade de alimentos. No Brasil, essas embalagens são tecnologias emergentes que estão em fase de adaptação no mercado nacional e de desenvolvimento por meio da pesquisa de novos mecanismos que podem ser empregados nas mais diversas aplicações.