title: Antimicrobial nanostructured starch based films for packaging.
abstract: Montmorillonite modified with a quaternary ammonium salt C30B/starch nanocomposite (C30B/ST-NC), silver nanoparticles/starch nanocomposite (Ag-NPs/ST-NC) and both silver nanoparticles/C30B/starch nanocomposites (Ag-NPs/C30B/ST-NC) films were produced. The nanoclay (C30B) was dispersed in a starch solution using an ultrasonic probe. Different concentrations of Ag-NPs (0.3, 0.5, 0.8 and 1.0mM) were synthesized directly in starch and in clay/starch solutions via chemical reduction method. Dispersion of C30B silicate layers and Ag-NPs in ST films characterized by X-ray and scanning electron microscopy showed that the presence of Ag-NPs enhanced clay dispersion. Color and opacity measurements, barrier properties (water vapor and oxygen permeabilities), dynamic mechanical analysis and contact angle were evaluated and related with the incorporation of C30B and Ag-NPs. Films presented antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans without significant differences between Ag-NPs concentrations. The migration of components from the nanostructured starch films, assessed by food contact tests, was minor and under the legal limits. These results indicated that the starch films incorporated with C30B and Ag-NPs have potential to be used as packaging nanostructured material.
authors.affiliation: Institute of Polymers and Composites (IPC) and Institute of Nanostructures, Nanomodelling and Nanofabrication (I3N), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal. Electronic address: anasofiaabreu@dep.uminho.pt.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Abreu
authors.affiliation: Institute of Polymers and Composites (IPC) and Institute of Nanostructures, Nanomodelling and Nanofabrication (I3N), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Oliveira
authors.affiliation: Institute of Polymers and Composites (IPC) and Institute of Nanostructures, Nanomodelling and Nanofabrication (I3N), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
authors.forename: Arsénio
authors.initials: A
authors.lastname: de Sá
authors.affiliation: Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Rui M
authors.initials: RM
authors.lastname: Rodrigues
authors.affiliation: Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cerqueira
authors.affiliation: Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: António A
authors.initials: AA
authors.lastname: Vicente
authors.affiliation: Institute of Polymers and Composites (IPC) and Institute of Nanostructures, Nanomodelling and Nanofabrication (I3N), University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal.
authors.forename: A V
authors.initials: AV
authors.lastname: Machado
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D000077215:Clay; D003116:Color; D055119:Elastic Modulus; D004926:Escherichia coli / Q000187:drug effects; D005502:Food; D018857:Food Packaging; D053768:Metal Nanoparticles / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D049329:Nanostructures / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis; D010539:Permeability; D012834:Silver / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects; D013213:Starch / Q000737:chemistry*; D013227:Steam; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D000890:Anti-Infective Agents; D013227:Steam; D014867:Water; D012834:Silver; D013213:Starch; D010100:Oxygen; D000077215:Clay
keywords: Antimicrobial activity; Food packaging; Nanostructured films; Organoclay; Silver nanoparticles; Starch