The scientists report that their study shows that an extract of rosemary added to packaging keeps meatpink for weeks. The use of carbon monoxide (CO) to keep packaged meat looking fresh is used inthe US and in other countries but is banned in the EU due to food safety concerns.
Rosemary has been traditionally used as an antioxidant and food preservative. The researchers in Spainsaid they added an extract of the popular herb to the polypropylene film used to package freshly cut meat in supermarket displays.
The addition created an "active packaging," the scientists explain in a report in the 6 Septemberissue of the American Chemical Society's Journal of Agricultural and Food Chemistry.
Such packaging goes beyond passively sealing food away from the environment, and plays an active role in keeping food fresh.
The rosemary-enhanced plastic film kept beef steaks looking pink and fresh for 14 days under conditions found in supermarkets.The use of rosemary also increased average display life by about two days compared to meat packaged in a traditional modified atmosphere mixture of oxygen,carbon dioxide and nitrogen gas.
"The usefulness of the present work is obvious and finds immediate application in the food industry," theresearchers reported.
The researchers are based at the University of Zaragoza.
During production, processing, distribution, and storage, food undergoes deterioration from chemical and microbiological processes. Typically, the oxidative deterioration of meat and meat products is caused by the degradation reactions of fats and pigments.
Consumers also perceive that a bright red colour indicates freshness, wholesomeness, and good quality.
Meat surface discoloration mostly depends on the oxidation rate of the red oxymyoglobin ontometmyoglobin, which gives meat an unattractive brown colour.
The most important factors influencing pigment oxidation are temperature, relative humidity, oxygen partial pressure, light, and lipid oxidation.
Both traditional food packaging and producers resolve food oxidation by adding synthetic antioxidants to the food productsduring processing.
Carbon monoxide is often used in modified atmosphere packaging (MAP) as a packaging technique for maintaining food quality by altering the atmospheric conditions within the package.
However, carbon monoxide also makes meat appear fresher than it actually is giving it a bright red pigment that masks any of the natural aging and spoilage of meats, according to critics of the practice.