Effects of Allium sativum essence oil as antimicrobial agent for food packaging plastic film

• A. sativum essential oil (AEO) added into plastic film for antibacterial purpose
• L. monocytogenes reduces significantly when contact with the antimicrobial films.
• Gram-negative bacteria such as E. coli are more resistant to AEO.
• Addition of AEO slightly affected the film mechanical properties.
• The film crystallinity increases significantly with the addition of AEO.

This research is focused on the development of antimicrobial (AM) plastic packaging by using blown film extrusion machine. Plastic films incorporated with 0, 2, 4, 6 and 8% Allium sativum essence oil (AEO) (% w/w) were tested for AM activities against beef related bacteria namely Listeria monocytogenes, Escherichia coli and Brochothrix thermosphacta. Mechanical properties, thermal properties and microstructure of films were investigated to justify the effects of AEO on the film physicomechanical functionality. The retraction zone in agar disk diffusion result shows that low-density-polyethylene/ethylene-vinyl-acetate (LDPE/EVA) co-polymer film with 8% AEO significantly reduce the concentration of bacteria with inhibition strength of L. monocytogenes > B. thermosphacta > E. coli. For challenge test, the AM films sufficiently reduced the growth rate of L. monocytogenes on cooked beef at 4 °C. High amount of AEO only slightly weakens the mechanical properties whereby film crystallinity increases significantly when small amount of AEO incorporated.Industrial relevanceThe current innovation is applied for the meat industry where a prolong storage of meat is required. A. sativum extract is a natural essential oil which will not cause health risk when in contact with food when applied in the packaging.