Background and Objectives: Due to increasing food production, it seems necessary a healthy and appropriate food delivered to consumers. One of the most important reasons for packaging is to prevent the growth of spoilage and pathogenic microorganisms in food. The aim of this study was to investigate the effect of  polylactic acid (PLA) films containing different concentrations of cumin essential oil on some microbial and chemical characteristics of minced beef meat.
Materials & Methods:  In order to study the antimicrobial effect of PLA films containing different concentrations of cumin essential oil, samples were examined for total aerobic bacterial count, psychotropic bacteria, coliform and Staphylococcus aureus at different times, day 0, 1, 2, 3, 4, 6 and 8.  In order to study the effect of films on total volatile nitrogen (TVB-N) of minced beef, the intended tests, were conducted on the same days of the microbial tests.
Results: The results of the present study indicated that total aerobic bacterial count, psychotropic, coliforms and S. aureus in samples packed with PLA films containing 0.8% cumin essential oil were significantly lower than control group (P<0.05). Moreover, increasing the essential oil concentration in PLA films significantly enhanced antimicrobial effect (P<0.05). The samples packed with PLA films containing different concentrations of essential oil had lower TVB-N contents compared to control (P<0.05) and generally a dose dependant trend was observed in the effect of adding cumin essential oils.
Conclusion: Based on our findings, the use of PLA films containing 0.8 % concentration of cumin essential oil could be a good method to keep minced meat during cold storage at least 8 days without any significant microbial and chemical spoilage.