ARS | Publication request: Physicochemical properties of apple puree-alginate films containing plant essential oils and oil compounds active against Escherichia coli 0157:H7

Submitted to: Progress in Nutrition
Publication Type: Abstract Only
Publication Acceptance Date: October 20, 2009
Publication Date: January 1, 2010
Citation: Olsen, C.W., Rojas-Grau, M., Avena Bustillos, R.D., Friedman, M., Henika, P.R., Martin-Belloso, O., Mc Hugh, T.H. 2010. Physicochemical properties of apple puree-alginate films containing plant essential oils and oil compounds active against Escherichia coli 0157:H7. Progress in Nutrition. p. 86

Technical Abstract: The use of edible films as carriers of antimicrobial plant essential oils and other phytochemicals constitutes an approach for external protection of food systems to reduce surface microbial populations and to enhance oxygen-barrier properties, thus enhancing food safety as well as shelf life. To demonstrate this possibility, we investigated the antimicrobial effects of 0.1-0.5% suspensions in apple puree with alginate used to prepare edible films of the following essential oil/oil compounds against the foodborne pathogen Escherichia coli Ol57:H7: oregano oil/ carvacrol; cinnamon oil/cinnamaldehyde; lemon grass oil/citral, as well as their effect on physical and barrier properties of apple puree-alginate based films. Bactericidal activities (BAm values, defined as the % of sample that induced a 50% decrease in colony forming units) against E. coli was evaluated after incubation for 3, 30 and 60 min at 21"C. Water vapor and oxygen permeability, and tensile properties of films were also evaluated. BAffl values against E. coli after incubation for 60 min at 21"C ranged from 0.011% for carvacrol to 0.087% for cinnamon oil. The data also show that the approximate order of antimicrobial activities was as follows: carvacrol > oregano oil > citral > lemon grass oil > cinnamaldehydc > cinnamon oil. Addition of plant essential oils/oil compounds into the apple puree-alginate films decreased water vapor permeability, increased oxygen pcrmeability, but did not significantly alter tensile properties. These results show that the plant-derived substances can be used to prepare apple puree-alginate based antimicrobial edible films or coatings to protect foods against pathogenic microorganisms