Control of bacteria growth on ready-to-eat beef loaves by antimicrobial plastic packaging incorporated with garlic oil

- Garlic oil added into polyethylene plastic film for antibacterial purpose.
- L. monocytogenes reduced significantly when contact with the antimicrobial films.
- Films with higher amount of garlic oil have weaker barrier to water vapor.
- Plastic films contained garlic oil has good potential to be used as food packaging.

This study was designated to ascertain the effectiveness of low density polyethylene (LDPE) based film incorporated with garlic oil for inhibition of food pathogen on ready-to-eat beef loaves. The blown film extrusion method was employed to produce film samples added with garlic oil in 2, 4, 6 and 8% w/w as well as sample with 0% w/w which served as control throughout the study. Besides, several analyses were also conducted to determine the water vapour barrier properties, thermal stability and bonding interaction of the plastic packaging as influenced by the incorporation of garlic oil. The outcomes of challenge test showed that regardless of the garlic oil amount (2-8% w/w), the antimicrobial plastic packaging was able to reduce the number of Listeria monocytogenes on beef loaves after 3, 6, 9 and 15 days of storage at 4 °C. However, there were insignificant effects on both Escherichia coli and Brochothrix thermosphacta. For water vapour barrier properties, films with higher amount of garlic oil proved to have weaker barrier properties. There was lack of significant difference in the thermal stability for all samples when tested with thermogravimetry analyser. Also, the infrared analysis indicated garlic oil does not change the polymer structure.