USDA and Spanish scientists develop anti-E. coli food wrap
Made from apple puree and oregano oil, product could displace traditional water-based washes; essential oils have natural antimicrobial abilities, but oregano is best against E. coli; sugary coating permits long-term adhesion to fruits and vegetables
Last Friday we reported on an anti-flu paint that could be applied to doorknobs. How about one to go directly on food? A team of scientists at the Department of Agriculture and the University of Lleida in Spain have developed an edible coating for fresh fruits and vegetables that not only kill E. coli bacteria but also provide additional flavorings and health benefits. Composed of apple puree and oregano oil — oregano being a natural enemy of bacteria — the coating could prove a worthy enemy of food coatings already on the market. “All produce-cleaning methods help to some degree, but our new coatings and films may provide a more concentrated, longer-lasting method for killing bacteria,” said Tara McHugh, of USDA’s Agricultural Research Service in Albany.
Scientists have long known about the antimicrobial abilities of plant-derived essential oils, but the apple puree and oregano oil coating is the first to incoporate them into a food safety wrap. McHugh and her colleagues tested a number of other oils, including cinnamon and lemongrass oils, but oregano performed the best, killing over 50 percent of sample bacteria in three minutes at concentrations as small as 0.034 percent. The apple puree has no antimicrobial properties but, as it is composed of sticky sugars and lipids, permits the coating to adhere to fruits and vegetables for far longer periods than water-based produce washes. The stickiness also gives the suspended antimicrobial agents a more concentrated exposure to bacterial surfaces, increasing the film’s germ-killing potential.
The research team has so far only tested its coating against E. coli, but it plans to investigate its utility in fighting salmonella and other foodborne pathogens in the near future. If all goes well, McHugh says the coating could be on the consumer market with a year or two. A full accounting of the experiment will appear in the 29 November issue of the American Chemical Society’s Journal of Agricultural and Food Chemistry.
-read more in this Science Daily report
