Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract only
Publication Acceptance Date: 2/11/2009
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Plant essential oils (EOs) are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contamination by pathogenic bacteria. EOs from cinnamon, allspice and clove bud are compatible with the sensory characteristics of apple-based edible films, and these films could extend product shelf-life and reduce risk of pathogen growth on food surfaces. The main objective of this study was to evaluate physical properties as well as antimicrobial activities against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes of allspice, cinnamon, and clove bud EOs in apple puree film-forming solutions formulated into edible films at 0.5-3.0% (w/w) concentrations. Antimicrobial activities were determined by two independent methods: overlay of the film on top of the bacteria and vapor phase diffusion of the antimicrobial from the film to the bacteria. The antimicrobial activities against the three pathogens were in the following order: cinnamon oil > clove bud oil > allspice. The antimicrobial films were more effective against L. monocytogenes than against the S. enterica. The presence of the EOs reduced the viscosity of the film-forming apple solutions at higher shear rates, but did not affect water vapor permeability of the films. The oils also increased elongation and darkened the colors of the films. The results of the present study show that some volatile EOs can be used to prepare apple-based antimicrobial edible films with good physical properties, and that the films are effective against major foodborne pathogens when evaluated by both direct contact and indirectly by vapors emanating from the films. Application of the antimicrobial apple films to contaminated produce and other foods merits study.