Synergic antimicrobial properties of Carvacrol essential oil and montmorillonite in biodegradable starch films

Author(s)

de Souza, Alana Gabrieli ^[1] ; Agostinho dos Santos, Nathalie Mirelle ^[2] ; da Silva Torin, Rondes Ferreira ^[2] ; Rosa, Derval dos Santos ^[1]

Affiliation

^[1] Fed Univ ABC, Engn Modeling & Appl Social Sci Ctr CECS, Santo Andre, SP - Brazil

^[2] State Ctr Technol Educ Paula Souza, Technol Fac Maua, Sao Paulo - Brazil

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 164, p. 1737-1747, DEC 1 2020.
• Web of Science Citations: 21

Abstract

This work evaluated the synergic effect of carvacrol essential oil (EO) and montmorillonite (MMT) (named hybrid compound), incorporated in thermoplastic starch (TPS) films in different contents (4.5, 9, and 15 wt%). TPS films were characterized by FTIR, FT-Raman, DSC, XRD, and antimicrobial assay. FTIR and FT-Raman indicated new hydrogen bonds between hybrid and starch, altering the thermal properties and requiring more energy to destroy the TPS-hybrid bonds. XRD analysis showed slight crystallinity changes, and TPS-15 hybrid showed an amorphous structure that allows the diffusion of EO thought the films. TPS-hybrid films showed antimicrobial behavior against E. coli due to the synergistic effect of MMT and EO, which resulted in strong antimicrobial effects due to the destabilization and partial destruction of the bacteria cellmembrane. The hybrid probably changed the E. coli cell permeability, respiration, and electron transport. TPS-15 hybrid sample presented the lowest crystallinity, facilitating the film's oil diffusion, maximizing the bacterium inhibitory effect, and acting as a biocidal agent. The results demonstrated that a hybrid compound is a good option for starch antimicrobial films for fresh food, such as fruits and vegetables. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• 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