RESUMO
The aim of this work was to develop and optimize a pH-responsive nanoparticle based on poly(D,L-lactide-co-glycolide) (PLGA) and chitosan (CHIT) for delivery of natural antimicrobial using trans-cinnamaldehyde (TCIN) as a model compound. The optimization was performed using a central composite design and the desirability function approach. The optimized levels of variables considering all significant responses were 4% (w/w) of TCIN and 6.75% (w/w) of CHIT. After, optimized nanoparticles were produced and characterized according to their physicochemical properties and their antimicrobial activity against Salmonella Typhimurium and Staphylococcus aureus. Optimized nanoparticles characterization indicated a satisfactory TCIN encapsulation (33.20⯱â¯0.85%), spherical shape, pH-responsive controlled release, with faster release in the presence of CHIT at low pH, and enhanced antimicrobial activity against both pathogens. TCIN encapsulation using PLGA coated with CHIT enhanced its antimicrobial activity and generated a delivery system with pH-sensitivity for controlled release with promising properties for food safety applications.
Assuntos
Anti-Infecciosos/química , Quitosana/sangue , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Acroleína/análogos & derivados , Acroleína/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Varredura Diferencial de Calorimetria , Quitosana/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Salmonella/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
Consumers are increasingly demanding foods with lower synthetic preservatives. Plant essential oils are natural compounds with remarkable antimicrobial properties and may be incorporated as emulsions into water-soluble polymers to form antimicrobial films. Coarse emulsions (diameters of 1.3-1.9 µm) and nanoemulsions (diameters of 180-250 nm) of clove bud (Syzygium aromaticum) and oregano (Origanum vulgare) essential oils were produced through low-speed mixing and ultrasonication, respectively. Methylcellulose was added for film-forming purposes. Both essential oils reduced the rigidity and increased the extensibility of the methylcellulose films, effects that were even more pronounced for nanodroplets. Both essential oils lessened the counts of yeasts and molds in sliced bread during 15 days, and droplet size reduction provided a further improvement in antimicrobial properties. Due to increased bioavailability, less preservative content might be used and still deliver the same antimicrobial efficiency if encapsulated in smaller particles.
