NEW TECHNOLOGIES TO PROCESS VALUE-ADDED, HEALTHY FOODS FROM FRUITS AND VEGETABLES
Location: Processed Foods Research
Title: Antibacterial Effects of Allspice, Garlic, and Oregano Essential Oils in Tomato Films Determined by Overlay and Vapor-Phase Methods
Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 10, 2009
Publication Date: August 28, 2009
Citation: Du, W., Olsen, C.W., Avena-Bustillos, R.D., Mc Hugh, T.H., Levin, C.E., Mandrell, R.E., Friedman, M. 2009. Antibacterial Effects of Allspice, Garlic, and Oregano Essential Oils in Tomato Films Determined by Overlay and Vapor-Phase Methods. Journal of Food Science. 74(7):M390-M397.
Interpretive Summary: The results of the present study show that allspice, garlic and oregano (plant-derived) essential oils can be used to prepare tomato-based antimicrobial edible films with good water vapor penetration and stretch strength properties for food applications by both direct contact and indirectly by vapor phase diffusion from the films.
Physical properties as well as antimicrobial activities against Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes of allspice, garlic and oregano essential oils (EOs) in tomato puree film forming solutions (TPFFS) formulated into edible films at 0.5-3.0% (w/w) concentrations were investigated in this study. 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 results indicate that the antimicrobial activities against the three pathogens were in the following order: oregano oil > allspice oil > garlic oil. Listeria monocytogenes was less resistant to essential oil vapors, while E. coli O157:H7 was more resistant to EOs as determined by both overlay and vapor phase diffusion tests. The presence of plant essential oil antimicrobials reduced the viscosity of TPFFS at the higher shear rates, but did not affect water vapor permeability of films. EOs increased elongation and darkened the color of films. The results of the present study show that the three plant-derived EOs can be used to prepare tomato-based antimicrobial edible films with good physical properties for food applications by both direct contact and indirectly by vapors emanating from the films.