Antimicrobial films containing hybrid systems aiming at packaging applications

Author(s)

Camani, Paulo H. ; da Silva Torin, Rondes F. ; de Souza, Clovis W. O. ; Zanata, Leonardo ; dos Santos Rosa, Derval

• Document type: Journal article
• Source: Polymer International; v. 70, n. 5, p. 8-pg., 2020-11-12.

Abstract

A critical issue in active packaging development using essential oils (EOs) is the high concentrations of these to obtain antimicrobial activity in the films. Therefore, this work was carried out to develop nanocomposite films, pursuing a potential minimal EO concentration with antimicrobial effectiveness, which could be applied in packaging. The films were prepared using low-density polyethylene (LDPE) containing a hybrid of montmorillonite and essential oil (MMT-EO), using two different EOs, carvacrol and eugenol, with 2 and 6 wt% oil concentration. The films were obtained in three steps. In the first (hybrid production), mixtures of montmorillonite clay with eugenol or carvacrol EOs were prepared. In the second (hybrid incorporation), these hybrids were incorporated into LDPE, obtaining LDPE/MMT-EO nanocomposites. Finally, a thermoforming process prepared the polymeric films. The samples were characterized by XRD and mechanical, contact angle and antimicrobial properties. The XRD results showed higher crystallinity for LDPE/MMT-EO compared to LDPE. The MMT was exfoliated into lamella forms, which could work as a physical barrier, reducing the oil diffusion. Besides, the contact angle results showed an increase in the hydrophilicity with the addition of the hybrids, which improved the antimicrobial action of the film. LDPE/MMT-E3 (1 wt% MMT and 2 wt% eugenol) showed the highest crystallinity, oil diffusivity, and mechanical and antimicrobial properties. These samples presented a reduction of a 2 log count of Staphylococcus aureus. The sum of the structural and antimicrobial properties of the LDPE/MMT-E3 film indicates its potential for food packaging. (c) 2020 Society of Industrial Chemistry (AU)

• FAPESP's process: 19/16301-6 - Starch aerogels containing modified nanocellullose for removal of heavy metals in wastewater from the industry sector
• Grantee: Paulo Henrique Camani
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/11277-7 - PBAT films with cellulose nanostructures treated with essential oils encapsulated for active packaging
• Grantee: Derval dos Santos Rosa
• Support Opportunities: Regular Research Grants