title: Effect of replacement of corn starch by whey protein isolate in biodegradable film blends obtained by extrusion.
abstract: The aim of this study was to evaluate the effect of replacing corn starch by whey protein isolated (WPI) in biodegradable polymer blends developed by extrusion. X-ray diffraction showed the presence of a Vh-type crystalline arrangement. The films were homogeneous, indicating strong interfacial adhesion between the protein and the thermoplastic starch matrix (TPS) as observed in scanning electron microscopy. The addition of WPI on TPS matrix promoted an increase in the thermal stability of the materials. It was observed 58.5% decrease in the water vapor permeability. The effect of corn starch substitution by WPI on mechanical properties resulted in a more resistant and less flexible film when compared the TPS film. The addition of WPI caused greenish yellow color and less transparent films. The substitution of corn starch by WPI made it possible to obtain polymer blends with improved properties and represents an innovation for application as a packaging material.
authors.affiliation: Food Science Department, Federal University of Lavras (UFLA), 37200-000, Lavras, MG, Brazil. Electronic address: vmachadoazevedo@gmail.com.
authors.forename: Viviane Machado
authors.initials: VM
authors.lastname: Azevedo
authors.affiliation: Food Science Department, Federal University of Lavras (UFLA), 37200-000, Lavras, MG, Brazil.
authors.forename: Soraia Vilela
authors.initials: SV
authors.lastname: Borges
authors.affiliation: National Agricultural Nanotechnology Laboratory, Embrapa Instrumentação, São Carlos, 13560-970, SP, Brazil.
authors.forename: José Manoel
authors.initials: JM
authors.lastname: Marconcini
authors.affiliation: Chemistry Department, Federal University of Minas Gerais, 37200-000, Belo Horizonte, MG, Brazil.
authors.forename: Maria Irene
authors.initials: MI
authors.lastname: Yoshida
authors.affiliation: National Agricultural Nanotechnology Laboratory, Embrapa Instrumentação, São Carlos, 13560-970, SP, Brazil.
authors.forename: Alfredo Rodrigues Sena
authors.initials: ARS
authors.lastname: Neto
authors.affiliation: Food Science Department, Federal University of Lavras (UFLA), 37200-000, Lavras, MG, Brazil.
authors.forename: Tamara Coelho
authors.initials: TC
authors.lastname: Pereira
authors.affiliation: Food Science Department, Federal University of Lavras (UFLA), 37200-000, Lavras, MG, Brazil.
authors.forename: Camila Ferreira Gonçalves
authors.initials: CFG
authors.lastname: Pereira
mesh_terms: D010539:Permeability; D019064:Product Packaging; D013213:Starch / Q000737:chemistry*; D013227:Steam; D000067816:Whey Proteins / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry
chemical_list: D013227:Steam; D000067816:Whey Proteins; D013213:Starch
keywords: Blends; Extrusion; Morphological properties; Polymers; Thermal stability