Antimicrobial volatile essential oils in edible films for food safety

Plant-derived essential oils (EOs) and oil compounds usually have a relatively high vapor pressure and are capable of reaching microbial pathogens through the liquid and the gas phase. Bioactivity of EOs in the vapor phase makes them useful as possible fumigants for stored commodity protection. The use of edible films as carriers of natural antimicrobials constitutes an approach for external protection of foods. These films can reduce surface microbial populations, enhance oxygen-barrier, reduce the need for synthetic packaging materials, and improve their recyclability by simplifying their structure. Incorporating antimicrobial compounds into edible films provides a novel way to improve the safety and shelflife of ready-to-eat foods. The evaluation of antimicrobial effectiveness of EOs in edible films can be done by different methods depending on relevant applications. The overlay method represents the direct contact of the films on food surfaces and the vapor phase method involves the inactivation of pathogens from a distance without direct contact of the films with the contaminated food. The antimicrobial data obtained with vapors diffused from edible films can serve as a guide for selection of appropriate levels of volatile EOs and their active constituents for incorporation into antimicrobial edible films for non-direct contact applications on food. Edible films containing plant-derived volatile EOs provide new ways to enhance microbial safety and shelf-life of foods.