RESUMO

Tannins from Acacia mearnsii were encapsulated using four different sol-gel methods acid (SGAR), basic (SGBR), silicate (SGSR) and non-hydrolytic (SGNHR) routes. The hybrid materials were analyzed using a set of techniques to characterize their structure, texture and morphology. The antimicrobial performance of the encapsulated materials was evaluated against different microorganisms (Staphylococcus aureus, Escherichia coli, Aspergillus niger and Candida sp.). The data showed that the encapsulation route significantly affects the characteristics of the resulting hybrid materials. Better functional performances were obtained using the silicate route, which produced mesoporous materials with a small surface area (0.96m2g-1) and small particle size (<1nm). These characteristics promoted the gradual release of tannins in an aqueous medium and improved their interactions with microorganisms. Furthermore, the process demonstrated the preservation of tannins after synthesis and increased antimicrobial activity (via a controlled tannin release), as demonstrated by the moderate activity against filamentous fungi and yeast.

Assuntos

Acacia/química , Anti-Infecciosos/química , Transição de Fase , Taninos/química , Adsorção , Aspergillus niger , Candida/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Hidrólise , Microscopia Confocal , Microscopia Eletrônica de Varredura , Nitrogênio/química , Tamanho da Partícula , Porosidade , Espalhamento de Radiação , Silicatos/química , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Raios X