Biobased films of nanocellulose and mango leaf extract for active food packaging: Supercritical impregnation versus solvent casting

authors	Bastante, CC; Silva, NHCS; Cardoso, LC; Serrano, CM; de la Ossa, EJM; Freire, CSR; Vilela, C
nationality	International
journal	FOOD HYDROCOLLOIDS
author keywords	Nanocellulose films; Mango leaf extract; Supercritical solvent impregnation; Solvent casting; Antioxidant and antimicrobial properties; Active food packaging
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.
publisher	ELSEVIER SCI LTD
issn	0268-005X
isbn	1873-7137
year published	2021
volume	117
digital object identifier (doi)	10.1016/j.foodhyd.2021.106709
web of science category	13
subject category	Chemistry, Applied; Food Science & Technology
unique article identifier	WOS:000640911000003