Antimicrobial Activity of Polylactic Acid Film Incorporated With Marjoram and Clove Essential Oils on Microbial and Chemical Properties of Minced Beef During Refrigerated Storage

Background: Active packaging is one of the new packaging technologies which causes interaction between packaging material and food with the aim of food shelf life extension while maintaining food safety and quality. Biodegradable films like polylactic acid (PLA) can be good alternatives to non-biodegradable plastics because of environmental pollution and concerns about the limitations of petroleum resources. Objective: This study was conducted to evaluate the efficacy of PLA film incorporated with marjoram and clove essential oils (EOs) (0.5 and 1% v/v) in maintaining the microbial and chemical quality of minced beef during refrigerated storage. Materials and Methods: Minced beef was packaged with PLA film incorporated with marjoram and clove EOs (0.5 and 1% v/v) alone and in combination and stored at refrigerator temperature for 10 days. Then, microbiological and chemical analyses were done at 0, 2, 4, 7 and 10 days of examination. Results: A reduction of 1 log CFU/g in total count was observed between groups with simultaneous use of EOs and control group (P<0.05) at day 7; however, there was not any significant difference between the mentioned groups at day 10. Active packaging with marjoram and clove EOs decreased the number of psychrotrophs in comparison to the control group and it was more evident at days 7 and 10. The number of Enterobacteriaceae in control and 1% clove EO/1% marjoram EO groups showed a difference of 3 log units at day 10. TVB-N of 1% clove EO/1% marjoram EO and 0.5% clove EO/1% marjoram EO showed significant differences from control at day 10 (P<0.05). Conclusion: The results of the current study have shown that the active PLA films can be a promising approach in order to maintain microbial and chemical quality of minced beef at refrigerator temperature for 10 days.