Extension of the shelf life of beef steaks packaged in a modified atmosphere by treatment with rosemary and displayed under UV-free lighting

Fresh beef steaks, either sprayed on the surface with a solution of rosemary and vitamin C or not sprayed, were packaged in 70%O₂₊20%CO₂₊10%N₂ and displayed at 1±1 °C without illumination or illuminated by a standard fluorescent lamp, a low-UV, colour-balanced lamp (Promolux®), or the fluorescent lamp with a UV filter. Metmyoglobin formation, lipid oxidation (2-thiobarbituric acid reactive substances), instrumental colour (CIE L*, a*, b*), psychrotrophic bacterial counts (PCA) and sensory discolouration and off-odour were determined. Results showed that the use of the antioxidant mixture of rosemary and vitamin C together with the absence of UV radiation significantly reduced the rates of metmyoglobin formation and lipid oxidation, as well as microbial growth, and extended the display life from about 10 to about 20 days.