Ultrastructural and antimicrobial impacts of allyl isothiocyanate incorporated in cellulose, β-cyclodextrin, and carbon nanotubes nanocomposites

Abstract

Antimicrobial nanobio packaging with controlled-release of active compounds is one of the most promising versions of active packaging. In this study, the antimicrobial effect of allyl isothiocyanate (AIT), complexed or not with β-cyclodextrin (βCD), and carbon nanotubes (CNTs) in cellulose films against Salmonella choleraesuis and Listeria innocua was investigated. Structural changes caused by AIT in bacteria were evaluated by transmission electron microscopy (TEM), as well as changes in the surface of the films, which were analyzed by atomic force microscopy and scanning electron microscopy. The active films inhibited the growth of both bacteria and caused damage to the cell membrane. The presence of inclusion complex and CNTs resulted in structural changes in films, such as the formation of lumps and reduction of roughness, respectively. Complexation of AIT with βCD and the use of CNTs increased the retention of the antimicrobial agent, which is desired to promote its controlled diffusion and consequently increase the preservative action of the film. However, when considering the use of βCD inclusion complexes, caution is necessary to prevent detrimental changes in the films' surface.