abstract
Antioxidant and antimicrobial free-standing films composed of nanofibrillated cellulose (NFC) and a polyphenolic-rich extract, viz. mango leaf extract (MLE), were produced via supercritical solvent impregnation (SSI) and conventional solvent casting film-processing methodologies. The CO2-assisted impregnation of NFC with MLE created robust films with thermal stability up to 250 ?C, good mechanical performance (Young?s modulus > 4.7 GPa), UV-light barrier properties, antioxidant capacity with maximum inhibition percentage of ca. 84%, and antimicrobial activity against Staphylococcus aureus (growth inhibition ?37%) and Escherichia coli (growth inhibition ?91%). The comparison of the NFC/MLE films prepared by SSI with those fabricated via solvent casting shows a clear advantage of the SSI methodology. Particularly, the antioxidant and antimicrobial activities are visibly higher in the films fabricated by the CO2-assisted impregnation of MLE into NFC. In fact, for the SSI films, the MLE components are mostly adsorbed at the surface and not in the bulk of the biopolymeric matrix, which translates into faster migrations and, hence, higher active properties. All these findings evinced the potential performance of the NFC/MLE films prepared by the eco-friendly SSI as UV-blocking, antioxidant, and antimicrobial bio-based materials for application as sustainable active food packaging.
subject category
Chemistry, Applied; Food Science & Technology
authors
Bastante, CC; Silva, NHCS; Cardoso, LC; Serrano, CM; de la Ossa, EJM; Freire, CSR; Vilela, C
our authors
Carla Vilela
Assistant Professor
Carmen Sofia da Rocha Freire Barros
Coordinating Researcher
Nuno Helder da Cruz Simões Silva
ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
This work was developed within the scope of the project CICECOAveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology (FCT)/MCTES. FCT is also acknowledged for the research contract under Scientific Employment Stimulus to C. Vilela (CEECIND/00263/2018). The NANOBIOINKS (CENTRO-01-0145-FEDER-031289) project is acknowledged for the research contract of N. H.C.S. Silva. The University of Cadiz is acknowledged for supporting the internship abroad of the researcher C. Cejudo Bastante by the project P18-RT-3272 of the Junta de Andalucia - FEDER funds 2014-2020.