ABSTRACT
Despite centuries of use for the preservation of foods and treatment of infections, plant-derived antimicrobials enjoy a renewed interest amongst food safety researchers and food product developers. This has come about in large part due to changing consumer purchase trends wherein foods with greater fresh-like characteristics but without compromise on food safety and quality are more desirable than foods using traditional preservatives. A substantial number of sources of plant-derived antimicrobials (PDAs) has been reported in the scientific literature, including numerous spice-bearing plants and their components (e.g., bark, leaves, stems, petals, etc.) with an equally diverse number of compound classes reported to bear antimicrobial activity against foodborne bacteria and fungi. Plant essential oils, or their components, are reported to inhibit foodborne microbes through membrane permeabilization, membrane electrical potential loss, causing leakage of ATP and other small molecules, or by the synergistic interaction with other antimicrobial preservatives or physical processes (e.g., heating, high pressure processing). PDAs have been applied in liquid suspensions, sometimes using encapsulation, or via vapor phase methods, to deliver antimicrobials to the food product to inhibit contaminating microorganisms. This chapter reviews the key compounds, application methods, uses, and limitations of plant-sourced antimicrobials for food preservation purposes.
