In this study, a researcher at Pamukkale University in Turkey assessed the potential of antimicrobial films for use in active food packaging. His full report was published in the journal Food Science and Technology.
For his experiment, the researchers packaged manti, a tortellini-like Turkish food, with antimicrobial films to extend its storage time at 4 C.
Before inoculating manti pieces with 5 log concentrations of two common food-poisoning bacteria, namely, Escherichia coli and Staphylococcus aureus, he separately incorporated polycaprolactone (PCL) with cinnamaldehyde (CNMA) and Punica granatum (pomegranate) methanolic extract (PME) to form antimicrobial diffusion films.
The films and manti pieces were then inserted in polyethylene bags that were filled with 100 percent N2 gas and monitored at 4 C for 28 days.
The researcher found that storage at low temperature and the addition of antimicrobial films effectively controlled microbial growth in the manti packages under modified atmospheric conditions for almost a month.
Both PCL-CNMA and PCL-PME films suppressed the growth of S. aureus for 21 days at 4 C, but the PCL-CNMA films had fewer colony forming units (CFU) at Day 28.
A similar result at Day 28 was observed for manti packages inoculated with E. coli; while PCL-PME films provided a bacteriostatic effect from Day 7 to Day 28, the PCL-CNMA films caused significantly larger reductions in CFU from Days 21 to 28.
Based on these findings, the researcher concluded that both cinnamaldehyde and P. granatum extract films can be used to control microbial growth in foods in modified-atmosphere packaging during cold storage.