Efficacy of polyethylene-based antimicrobial films containing principal constituents of basil

Abstract

The feasibility of low-density polyethylene (LDPE)-based films containing linalool or methylchavicol as antimicrobial (AM) packages to retard microbial growth on food surfaces was investigated. The AM LDPE-based films were tested for inhibition against selected microorganisms. Both compounds retained their AM activity, after an extrusion film-blowing process, against Escherichia coli in solid medium. Cheddar cheese was wrapped with the AM films and the packaged cheese samples were stored at 4 °C. The changes in the mesophilic aerobic bacteria and coliform, as well as yeast and mould counts were monitored. In addition, cheese samples inoculated with E. coli or Listeria innocua were wrapped with the AM films, stored at refrigerated (4 °C) or at abuse (12 °C) temperatures and the count of these microorganisms was monitored as a function of time. The results showed an inhibitory effect of these AM films against microbial growth in naturally contaminated cheese and in inoculated samples. The effect on suppression of E. coli and L. innocua growth was more pronounced at the abuse temperature. Methylchavicol-LDPE-based film exhibited a higher efficacy of inhibition than that of linalool-LDPE-based film. In addition, a sensory evaluation was performed with regards to possible taint in the flavour of the cheese. Taint in flavour as affected by linalool or methylchavicol was not significantly detectable by the panelists at the end of the storage period of 6 weeks. This study shows the potential use of polymeric films containing the principal constituents of basil as the AM components for enhancing quality and safety of cheeses.