University of Lille, France
Title: Antimicrobial films based on polyvinyl alcohol and hydroxypropyl-β-cyclodextrin for the prolonged release of sodium benzoate for potential food packaging application
Biography: Stephanie Degoutin
Our work concerns new poly(vinyl alcohol) (PVOH) cast films crosslinked with citric acid (CTR) and hydroxypropyl-β-cyclodextrin (HPβCD) and loaded with sodium benzoate (NaBz) as preservative agent, with different compositions of CTR, NaBz and HPβCD. The influence of HPβCD and processing parameters such as the crosslinking time on the physico-chemical and antimicrobial properties of the films were discussed. Permeability tests demonstrate that the presence of CTR and HPβCD does not modify PVOH barrier properties. Raman spectroscopy cartography shows that the NaBz distribution in the films is homogeneous, especially with HPβCD. The NaBz release in water is prolonged with HPβCD on one hand for high crosslinking times and, on the second hand, in the assays carried out at low temperature (4°C). The released quantity is increased from 40% to 70% when NaBz is included into HPβCD cavity. Antimicrobial assays were performed against S. aureus, E. coli, Candida albicans and Aspergillus niger. Without HPβCD, all films present a contact antimicrobial activity thanks to grafted CTR and the best diffusion activity was obtained for 6 wt% NaBz for the four microorganisms. With HPβCD, the antimicrobial activity by diffusion was increased with crosslinking times. These results demonstrate the high potential of PVOH/CTR/HPβCD cast films as antimicrobial food packagings.