Incorporation of spice essential oils into poly-lactic acid film matrix with the aim of extending microbiological and sensorial shelf life of ground beef

Plant-derived essential oils (EOs) are generally accepted as great potential to be used for extending shelf life of meat and meat products. In this study, biodegradable active PLA composite films were produced via addition of different percentage of Mentha piperita EO (MPO), Bunium percicum EO (BPO) and nanocellulose (NC), and their organoleptic and antibacterial effects were assessed in ground beef during 12 days storage at 4 °C. Physical examinations of the films revealed that regardless of type of the EOs, a negative correlation was recorded between water vapor permeability of the composites and the concentration of active agents, and with addition of the EOs yellowness and lightness parameters of the resultant composites negatively changed. Based on microbiological analysis of the meat samples, both MPO and BPO showed effective antibacterial activity against all of the tested microorganisms, where in terms of total bacterial counts, combination of higher concentrations (1% v/v) of both EOs in the primary formulation of active film extended the product shelf life (from 4 to 7 days) in comparison with control sample. Furthermore, concerning organoleptic characteristics, the treated ground beef samples were generally acceptable and treatment with PLA/0.5MPO/NC film resulted in the best outcome.