Edible Chitosan Films and Their Nanosized Counterparts Exhibit Antimicrobial Activity and Enhanced Mechanical and Barrier Properties
Laidson P. Gomes,
Hiléia K. S. Souza,
José M. Campiña,
Cristina T. Andrade,
António F. Silva,
Maria P. Gonçalves,
Vania M. Flosi Paschoalin
Affiliations
Laidson P. Gomes
REQUIMTE/LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Hiléia K. S. Souza
REQUIMTE/LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
José M. Campiña
Departamento de Química e Bioquímica, Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Ciências, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
Cristina T. Andrade
Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Av. Horácio Macedo, 2030-Cidade Universitária, 21941-598 Rio de Janeiro, Brazil
António F. Silva
Departamento de Química e Bioquímica, Centro de Investigação em Química da Universidade do Porto (CIQ-UP), Faculdade de Ciências, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
Maria P. Gonçalves
REQUIMTE/LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Vania M. Flosi Paschoalin
Instituto de Química, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, Cidade Universitária, 21941-909 Rio de Janeiro, Brazil
Chitosan and chitosan-nanoparticles were combined to prepare biobased and unplasticized film blends displaying antimicrobial activity. Nanosized chitosans obtained by sonication for 5, 15, or 30 min were combined with chitosan at 3:7, 1:1, and 7:3 ratios, in order to adjust blend film mechanical properties and permeability. The incorporation of nanosized chitosans led to improvements in the interfacial interaction with chitosan microfibers, positively affecting film mechanical strength and stiffness, evidenced by scanning electron microscopy. Nanosized or blend chitosan film sensitivity to moisture was significantly decreased with the drop in biocomposite molecular masses, evidenced by increased water solubility and decreased water vapor permeability. Nanosized and chitosan interactions gave rise to light biobased films presenting discrete opacity and color changes, since red-green and yellow-blue colorations were affected. All chitosan blend films exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. The performance of green unplasticized chitosan blend films displaying diverse morphologies has, thus, been proven as a potential step towards the design of nontoxic food packaging biobased films, protecting against spoilage microorganisms, while also minimizing environmental impacts.
