Resumo A preocupação com a qualidade ambiental aumentou na sociedade porque o desenvolvimento industrial e tecnológico liberou altos níveis de contaminantes no meio ambiente, como os hidrocarbonetos. Uma técnica amplamente utilizada para a biorremediação é a bioestimulação, que pode ser reforçada por microencapsulação. O objetivo desta pesquisa foi formular compostos de nitrogênio e fósforo de liberação lenta usando diferentes matrizes de polímeros (Alginato/Capsul®, Carboximetilcelulose) e compará-los com o produto agrícola Osmocote® e meio mineral Bushnell-Haas como agentes de bioestimulação hidrocarbonoclasticos no meio ambiente para biorremediação poluente. N (nitrogênio) e P(fósforo) foram imobilizados usando técnicas de liofilização e gelificação iónica. As experiências foram conduzidas usando material encapsulado e avaliadas para produção de biomassa, consumo de glicose como fonte de carbono orgânico e fornecimento de N e P. O compósito imobilizado composto por carboximetil celulose apresentou os melhores resultados de degradação glicosídica (66,7%) e bioestimulação microbiana (350 mg L-1 de proteína) em comparação com os sistemas contendo nutrientes livres (11,3% e 150 mg L-1 de degradação glicosídica e bioestimulação microbiana respectivamente). Assim, este composto é um potencial produto de liberação lenta para processos de biorremediação.

Abstract Concern for environmental quality has increased in society because industrial and technological development has released high levels of contaminants into the environment, such as hydrocarbons. A technique widely used for bioremediation is biostimulation, which may be enhanced by microencapsulation. This research formulated slow-release nitrogen and phosphorus compounds using different polymer (Alginate/Capsul®, carboxymethyl cellulose) matrices and compared them with the agricultural product Osmocote® and mineral medium Bushnell-Haas as hydrocarbonoclastics biostimulation agents in the environment for pollutant bioremediation. N (nitrogen) and P (phosphorus) were immobilized using lyophilization and ionic gelation techniques. Experiments were conducted using encapsulated material and evaluated for biomass production, glucose consumption as organic carbon source and N and P supply. The immobilized carboxymethyl cellulose compound showed the best results of glycosidic degradation (66.7%) and microbial biostimulation (350 mg L-1 protein) compared to systems containing free nutrients (11.3% and 150 mg L-1 degradation glycosidic and microbial biostimulation, respectively). Thus, this compound is a potential slow release product for bioremediation processes.

Strontium (Sr) is known to positively affect the mechanism of bone remodelling. Consequently, calcium phosphate bioceramics associated with alginate matrices containing strontium could improve bone regeneration due to gradual strontium release. This work aims to incorporate Sr on microspheres of alginate (ALG)/β-tricalcium phosphate (β-TCP) and evaluates the in vitro release of strontium ions into a buffer solution at pH 4.0 and 7.4. In this study, strontium chloride was employed as a cross-linking agent and Sr source. Energy dispersive spectroscopy (EDS) showed that strontium was incorporated mainly at the surface of the microspheres produced. The in vitro experiments revealed that there is a rapid strontium release up to 24 h at pH 7.4 due to Sr location on microspheres' surface. At pH 4.0 both calcium and strontium were released due to the β-TCP dissolution.

Microcapsules containing lactoferrin were produced by spray drying using dextrin:octenylsuccinate starch, as wall materials. Porosity characteristics of spray-dried microcapsules were investigated by mercury intrusion porosimetry and nitrogen adsorption. The outer and inner structures of microcapsules were studied by Scanning Electron Microscopy and sizes were determined by Laser Diffraction. Results indicate that all microcapsules presents adsorption isotherm of type II and that micropores on the microcapsules surface will be very few or none. Our results show that microstructure, surface area and size of microcapsules are affected by dextrin: octenylsuccinate starch proportion. Pore characteristics for various microcapsules are found to be different.

alpha-tocopherol was encapsulated in a glassy food model based on solution of maltodextrin (DE 20) and gelatin, through the use of quick freeze and freeze-drying procedures. The ratio of the maltodextrin, alpha-tocopherol and gelatin was 3:2:1 respectively. The morphology of the glassy food model was observed by scanning electron microscopy, whose analyses showed a slightly smooth surface and a rather fragile and porous structure due to cavities formed by ice crystals during freezing, and the absence of crystalline structure. It was observed by x ray diffraction that the material is an amorphous state. The samples stored in a specific plastic vessel isolated from gas and light held its amorphous state with no variations that concern to morphology and keeping 100% of the encapsulated alpha-tocopherol up to 90 days at 25 and 35 °C.