title: Optimized pH-responsive film based on a eutectic mixture-plasticized chitosan.
abstract: Chitosan (CS, 2g/100mL)/curcumin 1g/100mL in acetic acid aqueous solution were used to prepare films to be used as food indicator. Microcrystalline cellulose (MCC) and a eutectic mixture (DES) were incorporated as reinforcing and plasticizing agents, respectively. The MCC content (133 mas%) and DES composition (7.93 mass%), based on CS dry mass, were optimized. The properties of the DES-plasticized film were compared to those for the unplasticized and glycerol (G)-plasticized CS films. The DES-plasticized film presented initial temperature of thermal decomposition at 267.7°C, dynamic glass transition at 149.3°C, water vapor permeability of 7.21×10-10gs-1m-1Pa-1, water solubility of 3.07% and stress at break of 20.1MPa. The incorporation of MCC contributed to increase the crystallinity of the composite films. Colorimetric tests, carried out in aqueous environments for the DES-plasticized film, revealed accentuated color changes, mainly at pHs higher than pH 8.
authors.affiliation: Programa de Pós-Graduação em Ciência de Alimentos, Instituto de Química, Universidade Federal do Rio de Janeiro, Avenida Athos da Silveira Ramos 149, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Pamela F
authors.initials: PF
authors.lastname: Pereira
authors.affiliation: Programa de Pós-Graduação em Ciência de Alimentos, Instituto de Química, Universidade Federal do Rio de Janeiro, Avenida Athos da Silveira Ramos 149, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Avenida Horácio Macedo 2030, 21941-598 Rio de Janeiro, RJ, Brazil. Electronic address: ctandrade@ima.ufrj.br.
authors.forename: Cristina T
authors.initials: CT
authors.lastname: Andrade
keywords: Chitosan; Chitosan (PubChem CID: 71853); Choline chloride (PubChem CID: 6209); Curcumin; Curcumin (PubChem CID: 969516); Eutectic mixture; Glycerol (PubChem CID: 753); Intelligent packaging; Microcrystalline cellulose; Microcrystalline cellulose (PubChem CID: 62698)