(NaturalNews) An edible film based on simple tomato
puree might be able to protect foods from contamination by E. coli and
other bacteria, according to a study conducted by researchers from the U.S.
Department of Agriculture's Agriculture Research Service and the Western Regional
Research Centre, Processed Foods, and published in the Journal of Food
The researchers made an edible, food-coating, tomato-based film and added
the chemical carvacrol in concentrations of 0,
0.5, 0.75, 1.0 and 1.5 percent. They then inoculated these films with the
O157:H7 strain of E. coli.
Carvacrol is the primary ingredient in oregano
The researchers found that the carvacrol films
successfully inhibited bacterial growth and were most effective at a
concentration of 0.75 percent.
E. coli O157:H7 grew normally on agar plates with films lacking carvacrol incubated at 35°C for 24 or 48 hours,"
the researchers wrote. "By contrast, no growth was observed on the
plates around the film discs containing 0.75 per cent or 1 per cent carvacrol. The extent of bacterial growth inhibition
increased as the per cent of carvacrol in the
films was increased."
The researchers tested two different methods of making the film, and
concluded that continuous casting would be preferable for translating the
film into large-scale production.
Demand for natural antimicrobial produces is growing as consumers become
increasingly wary of synthetic preservatives. The researchers noted that
since the antimicrobial film tested in their study is tomato-based, it might
actually provide some of the same health benefits as eating the fruit.
"Consumption of tomatoes,
tomato products and isolated bioactive tomato ingredients is reported to be
associated with lowered risk of cancer, heart disease, diabetes and
hypertension," they said.
The researchers have already begun studies to test whether films based on
other fruits and vegetables can be used to inhibit pathogen growth in
Sources for this story include: www.foodnavigator-usa.com.