Antibacterial effects of allspice, garlic, and oregano essential oils in tomato films determined by overlay and vapor-phase methods.
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% to 3% (w/w) concentrations were investigated in this study. Antimicrobial activities were determined by 2 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 3 pathogens were in the following order: oregano oil > allspice oil > garlic oil. Listeria monocytogenes was less resistant to EO 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 EO 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 3 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.
Du
W-X
WX
Processed Foods Research, Western Regional Research Center, US Dept of Agriculture, Agricultural Research Service, 800 Buchanan St, Albany, CA 94710, USA.
Olsen
C W
CW
Avena-Bustillos
R J
RJ
McHugh
T H
TH
Levin
C E
CE
Mandrell
R
R
Friedman
Mendel
M
D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004548:Elasticity; D004755:Enterobacteriaceae / Q000187:drug effects*; D019453:Escherichia coli O157 / Q000187:drug effects; D005516:Food Microbiology; D018857:Food Packaging / Q000295:instrumentation; D005638:Fruit / Q000737:chemistry*; D005737:Garlic / Q000737:chemistry; D008089:Listeria monocytogenes / Q000187:drug effects*; D018551:Solanum lycopersicum / Q000737:chemistry*; D008826:Microbial Sensitivity Tests / Q000379:methods; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D031341:Origanum / Q000737:chemistry; D010539:Permeability; D010858:Pigmentation; D027841:Pimenta / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D019779:Salmonella enterica / Q000187:drug effects; D013718:Tensile Strength; D014783:Viscosity
D000890:Anti-Infective Agents; D009822:Oils, Volatile