Antimicrobial effectiveness of oregano and sage essential oils incorporated into whey protein films or cellulose-based filter paper.
BACKGROUND
In this study the antimicrobial effectiveness of oregano and sage essential oils (EOs) incorporated into two different matrices, whey protein isolate (WPI) and cellulose-based filter paper, was analysed.


RESULTS
Antimicrobial properties of WPI-based films containing oregano and sage EOs were tested against Listeria innocua, Staphylococcus aureus and Salmonella enteritidis. Oregano EO showed antimicrobial activity against all three micro-organisms. The highest inhibition zones were against L. innocua. However, sage EO did not show antimicrobial activity against any of the micro-organisms. Antimicrobial activity was confirmed for both EOs using cellulose-based filter paper as supporting matrix, although it was significantly more intense for oregano EO. Inhibition surfaces were significantly greater when compared with those of the WPI films. This finding is likely due to the higher porosity and diffusivity of the active compounds in the filter paper.


CONCLUSIONS
The interactions between the EOs and the films have a critical effect on the diffusivity of the active compounds and therefore on the final antimicrobial activity. As a result, to obtain active edible films, it is necessary to find the equilibrium point between the nature and concentration of the active compounds in the EO and the formulation of the film.
Royo
Maite
M
Departamento de Tecnología de Alimentos, Universidad Pública de Navarra, Campus Arrosadía S/N, Pamplona, Spain.
Fernández-Pan
Idoya
I
Maté
Juan I
JI
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002482:Cellulose / Q000737:chemistry*; D004058:Diffusion; D004305:Dose-Response Relationship, Drug; D005516:Food Microbiology; D018857:Food Packaging / Q000295:instrumentation*; D008087:Listeria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008894:Milk Proteins / Q000737:chemistry*; D009822:Oils, Volatile / Q000494:pharmacology*; D031341:Origanum / Q000737:chemistry*; D010209:Paper; D016062:Porosity; D012477:Salmonella enteritidis / Q000187:drug effects; D027543:Salvia officinalis / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects; D013997:Time Factors; D000067816:Whey Proteins
D000890:Anti-Infective Agents; D008894:Milk Proteins; D009822:Oils, Volatile; D000067816:Whey Proteins; D002482:Cellulose