Influence of low oxygen concentrations on color stability of modified atmosphere packaged beef

• For color stability of beef oxygen must be totally excluded from the packages • The oxygen content decreases stronger at higher initial oxygen content in the packages • The discoloration and oxygen content were measured optically through the packaging • The oxygen sensor spots can be reused due to application to microscope slides • The non-invasive methods allow reproduction of the experiment in slaughterhouses The influence of low oxygen concentrations on the development of color and the myoglobin redox states over storage time was analyzed, to determine whether there are conditions that increase discoloration. Beef slices were packaged in atmospheres containing nitrogen gas and 0%, 0.5%, 1%, 1.5%, 3%, and 5% of oxygen. The samples were stored at 2°C for 14 days. During storage, color, reflectance and oxygen concentration were measured optically through the packaging. The color difference ΔE 2000 and the relative oxymyoglobin (OMb), deoxymyoglobin (DMb), and metmyoglobin (MMb) levels were calculated. After 14 days, the oxygen concentrations changed to 0.09% (0%), 0.36% (0.5%), 0.92% (1%), 1.28% (1.5%) 2.55% (3%), and 4.29% (5%). Regarding MMb formation, the 0% samples (ΔMMb 0-14d 11.1%) were significantly ( p